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Vafaei R, Sikkel MB, Wilkins J. Case report: unmasked Brugada pattern in a post-arrest patient after ketamine induction for intubation in the emergency department. CAN J EMERG MED 2024; 26:62-64. [PMID: 37751080 DOI: 10.1007/s43678-023-00596-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 09/04/2023] [Indexed: 09/27/2023]
Affiliation(s)
- Rod Vafaei
- Emergency Medicine Residency Program, University of British Columbia, Victoria, BC, Canada.
| | - Markus B Sikkel
- Division of Cardiology, Center for Cardiovascular Innovation, University of British Columbia, Vancouver, BC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Division of Cardiology, Royal Jubilee Hospital, Coronation Annex, Victoria, BC, Canada
| | - Jacob Wilkins
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Emergency Medicine, University of British Columbia, Vancouver, BC, Canada
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2
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Iqbal MB, Robinson SD, Nadra IJ, Das D, van Zyl M, Sikkel MB, Della Siega A. The Efficacy and Safety of an Adjunctive Transcoronary Pacing Strategy During Rotational Atherectomy: ROTA-PACE Study. JACC Cardiovasc Interv 2023; 16:2189-2190. [PMID: 37409992 DOI: 10.1016/j.jcin.2023.05.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 05/02/2023] [Accepted: 05/09/2023] [Indexed: 07/07/2023]
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3
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Sau A, Kapadia S, Al-Aidarous S, Howard J, Sohaib A, Sikkel MB, Arnold A, Waks JW, Kramer DB, Peters NS, Ng FS. Temporal Trends and Lesion Sets for Persistent Atrial Fibrillation Ablation: A Meta-Analysis With Trial Sequential Analysis and Meta-Regression. Circ Arrhythm Electrophysiol 2023; 16:e011861. [PMID: 37589197 PMCID: PMC10510845 DOI: 10.1161/circep.123.011861] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 08/03/2023] [Indexed: 08/18/2023]
Abstract
BACKGROUND Ablation for persistent atrial fibrillation (PsAF) has been performed for over 20 years, although success rates have remained modest. Several adjunctive lesion sets have been studied but none have become standard of practice. We sought to describe how the efficacy of ablation for PsAF has evolved in this time period with a focus on the effect of adjunctive ablation strategies. METHODS Databases were searched for prospective studies of PsAF ablation. We performed meta-regression and trial sequential analysis. RESULTS A total of 99 studies (15 424 patients) were included. Ablation for PsAF achieved the primary outcome (freedom of atrial fibrillation/atrial tachycardia rate at 12 months follow-up) in 48.2% (5% CI, 44.0-52.3). Meta-regression showed freedom from atrial arrhythmia at 12 months has improved over time, while procedure time and fluoroscopy time have significantly reduced. Through the use of cumulative meta-analyses and trial sequential analysis, we show that some ablation strategies may initially seem promising, but after several randomized controlled trials may be found to be ineffective. Trial sequential analysis showed that complex fractionated atrial electrogram ablation is ineffective and further study of this treatment would be futile, while posterior wall isolation currently does not have sufficient evidence for routine use in PsAF ablation. CONCLUSIONS Overall success rates from PsAF ablation and procedure/fluoroscopy times have improved over time. However, no adjunctive lesion set, in addition to pulmonary vein isolation, has been conclusively demonstrated to be beneficial. Through the use of trial sequential analysis, we highlight the importance of adequately powered randomized controlled trials, to avoid reaching premature conclusions, before widespread adoption of novel therapies.
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Affiliation(s)
- Arunashis Sau
- National Heart and Lung Institute, Imperial College London, United Kingdom (A. Sau, S.K., J.H., M.B.S., A.A., D.B.K., N.S.P., F.S.N.)
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (A. Sau, J.H., A.A., N.S.P., F.S.N.)
| | - Sharan Kapadia
- National Heart and Lung Institute, Imperial College London, United Kingdom (A. Sau, S.K., J.H., M.B.S., A.A., D.B.K., N.S.P., F.S.N.)
| | - Sayed Al-Aidarous
- UCL Institute of Cardiovascular Science, University College London, United Kingdom (S.A.-A.)
| | - James Howard
- National Heart and Lung Institute, Imperial College London, United Kingdom (A. Sau, S.K., J.H., M.B.S., A.A., D.B.K., N.S.P., F.S.N.)
| | - Afzal Sohaib
- The Barts Heart Centre, St Bartholomew’s Hospital, Barts Health NHS Trust, London, United Kingdom (A. Sohaib)
| | - Markus B. Sikkel
- National Heart and Lung Institute, Imperial College London, United Kingdom (A. Sau, S.K., J.H., M.B.S., A.A., D.B.K., N.S.P., F.S.N.)
- Royal Jubilee Hospital, Victoria, Canada (M.B.S.)
| | - Ahran Arnold
- National Heart and Lung Institute, Imperial College London, United Kingdom (A. Sau, S.K., J.H., M.B.S., A.A., D.B.K., N.S.P., F.S.N.)
| | - Jonathan W. Waks
- Harvard-Thorndike Electrophysiology Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (J.W.W.)
| | - Daniel B. Kramer
- National Heart and Lung Institute, Imperial College London, United Kingdom (A. Sau, S.K., J.H., M.B.S., A.A., D.B.K., N.S.P., F.S.N.)
- Richard A. and Susan F. Smith Center for Outcomes Research in Cardiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA (D.B.K.)
| | - Nicholas S. Peters
- National Heart and Lung Institute, Imperial College London, United Kingdom (A. Sau, S.K., J.H., M.B.S., A.A., D.B.K., N.S.P., F.S.N.)
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (A. Sau, J.H., A.A., N.S.P., F.S.N.)
| | - Fu Siong Ng
- National Heart and Lung Institute, Imperial College London, United Kingdom (A. Sau, S.K., J.H., M.B.S., A.A., D.B.K., N.S.P., F.S.N.)
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (A. Sau, J.H., A.A., N.S.P., F.S.N.)
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4
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Lu N, Cheung CC, Sikkel MB, CHAKRABARTI SANTABHANU, Sterns LD, Andrade JG, Novak PG, Hawkins NM, Laksman Z, Leather RA, Deyell MW, Krahn AD, Yeung-Lai-Wah JA, Bennett MT. PO-692-07 IMPACT OF LEFT VENTRICULAR LEAD REPOSITIONING FOR MODERATELY INCREASED CAPTURE THRESHOLD. Heart Rhythm 2022. [DOI: 10.1016/j.hrthm.2022.03.642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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5
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Hesketh LM, Sikkel MB, Mahoney-Sanchez L, Mazzacuva F, Chowdhury RA, Tzortzis KN, Firth J, Winter J, MacLeod KT, Ogrodzinski S, Wilder CDE, Patterson LH, Peters NS, Curtis MJ. OCT2013, an ischaemia-activated antiarrhythmic prodrug, devoid of the systemic side effects of lidocaine. Br J Pharmacol 2022; 179:2037-2053. [PMID: 34855992 DOI: 10.1111/bph.15764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 09/28/2021] [Accepted: 11/04/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Sudden cardiac death (SCD) caused by acute myocardial ischaemia and ventricular fibrillation (VF) is an unmet therapeutic need. Lidocaine suppresses ischaemia-induced VF, but its utility is limited by side effects and a narrow therapeutic index. Here, we characterise OCT2013, a putative ischaemia-activated prodrug of lidocaine. EXPERIMENTAL APPROACH The rat Langendorff-perfused isolated heart, anaesthetised rat and rat ventricular myocyte preparations were utilised in a series of blinded and randomised studies to investigate the antiarrhythmic effectiveness, adverse effects and mechanism of action of OCT2013, compared with lidocaine. KEY RESULTS In isolated hearts, OCT2013 and lidocaine prevented ischaemia-induced VF equi-effectively, but OCT2013 did not share lidocaine's adverse effects (PR widening, bradycardia and negative inotropy). In anaesthetised rats, i.v. OCT2013 and lidocaine suppressed VF and increased survival equi-effectively; OCT2013 had no effect on cardiac output even at 64 mg·kg-1 i.v., whereas lidocaine reduced it even at 1 mg·kg-1 . In adult rat ventricular myocytes, OCT2013 had no effect on Ca2+ handling, whereas lidocaine impaired it. In paced isolated hearts, lidocaine caused rate-dependent conduction slowing and block, whereas OCT2013 was inactive. However, during regional ischaemia, OCT2013 and lidocaine equi-effectively hastened conduction block. Chromatography and MS analysis revealed that OCT2013, detectable in normoxic OCT2013-perfused hearts, became undetectable during global ischaemia, with lidocaine becoming detectable. CONCLUSIONS AND IMPLICATIONS OCT2013 is inactive but is bio-reduced locally in ischaemic myocardium to lidocaine, acting as an ischaemia-activated and ischaemia-selective antiarrhythmic prodrug with a large therapeutic index, mimicking lidocaine's benefit without adversity.
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Affiliation(s)
- Louise M Hesketh
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
| | - Markus B Sikkel
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - Laura Mahoney-Sanchez
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
| | | | - Rasheda A Chowdhury
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - Konstantinos N Tzortzis
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - Jahn Firth
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - James Winter
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
| | - Kenneth T MacLeod
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | | | - Catherine D E Wilder
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
| | | | - Nicholas S Peters
- National Heart and Lung Institute, Faculty of Medicine, ICTEM, The Hammersmith Hospital, Imperial College London, London, UK
| | - Michael J Curtis
- Cardiovascular Division, Faculty of Life Sciences and Medicine, The Rayne Institute, St Thomas' Hospital, King's College London, London, UK
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6
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Guntrip R, Graham AJ, Sodhi A, Leather RA, Novak PG, Sterns LD, Sikkel MB. PO-710-02 PATIENT COMORBIDITIES AND ABLATION TECHNIQUE ARE IMPORTANT DETERMINANTS OF FIRST PASS PULMONARY VEIN ISOLATION. Heart Rhythm 2022. [DOI: 10.1016/j.hrthm.2022.03.1118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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7
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Kim MY, Coyle C, Tomlinson DR, Sikkel MB, Sohaib A, Luther V, Leong KM, Malcolme-Lawes L, Low B, Sandler B, Lim E, Todd M, Fudge M, Wright IJ, Koa-Wing M, Ng FS, Qureshi NA, Whinnett ZI, Peters NS, Newcomb D, Wood C, Dhillon G, Hunter RJ, Lim PB, Linton NWF, Kanagaratnam P. Ectopy-triggering ganglionated plexuses ablation to prevent atrial fibrillation: GANGLIA-AF study. Heart Rhythm 2022; 19:516-524. [PMID: 34915187 PMCID: PMC8976158 DOI: 10.1016/j.hrthm.2021.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/30/2021] [Accepted: 12/01/2021] [Indexed: 01/26/2023]
Abstract
BACKGROUND The ganglionated plexuses (GPs) of the intrinsic cardiac autonomic system may play a role in atrial fibrillation (AF). OBJECTIVE We hypothesized that ablating the ectopy-triggering GPs (ET-GPs) prevents AF. METHODS GANGLIA-AF (ClinicalTrials.gov identifier NCT02487654) was a prospective, randomized, controlled, 3-center trial. ET-GPs were mapped using high frequency stimulation, delivered within the atrial refractory period and ablated until nonfunctional. If triggered AF became incessant, atrioventricular dissociating GPs were ablated. We compared GP ablation (GPA) without pulmonary vein isolation (PVI) against PVI in patients with paroxysmal AF. Follow-up was for 12 months including 3-monthly 48-hour Holter monitors. The primary end point was documented ≥30 seconds of atrial arrhythmia after a 3-month blanking period. RESULTS A total of 102 randomized patients were analyzed on a per-protocol basis after GPA (n = 52; 51%) or PVI (n = 50; 49%). Patients who underwent GPA had 89 ± 26 high frequency stimulation sites tested, identifying a median of 18.5% (interquartile range 16%-21%) of GPs. The radiofrequency ablation time was 22.9 ± 9.8 minutes in GPA and 38 ± 14.4 minutes in PVI (P < .0001). The freedom from ≥30 seconds of atrial arrhythmia at 12-month follow-up was 50% (26 of 52) with GPA vs 64% (32 of 50) with PVI (log-rank, P = .09). ET-GPA without atrioventricular dissociating GPA achieved 58% (22 of 38) freedom from the primary end point. There was a significantly higher reduction in antiarrhythmic drug usage postablation after GPA than after PVI (55.5% vs 36%; P = .05). Patients were referred for redo ablation procedures in 31% (16 of 52) after GPA and 24% (12 of 50) after PVI (P = .53). CONCLUSION GPA did not prevent atrial arrhythmias more than PVI. However, less radiofrequency ablation was delivered to achieve a higher reduction in antiarrhythmic drug usage with GPA than with PVI.
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Affiliation(s)
- Min-Young Kim
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom; Imperial Centre for Cardiac Engineering, Imperial College London, London, United Kingdom
| | - Clare Coyle
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom; Imperial Centre for Cardiac Engineering, Imperial College London, London, United Kingdom
| | - David R Tomlinson
- Cardiology Department, Derriford Hospital, University Hospitals Plymouth NHS Trust, Plymouth, United Kingdom
| | - Markus B Sikkel
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Afzal Sohaib
- Cardiology Department, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom
| | - Vishal Luther
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Kevin M Leong
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Louisa Malcolme-Lawes
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Benjamin Low
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Belinda Sandler
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Elaine Lim
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Michelle Todd
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Michael Fudge
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Ian J Wright
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Michael Koa-Wing
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Fu Siong Ng
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Norman A Qureshi
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Zachary I Whinnett
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Nicholas S Peters
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom; Imperial Centre for Cardiac Engineering, Imperial College London, London, United Kingdom
| | - Daniel Newcomb
- Cardiology Department, Derriford Hospital, University Hospitals Plymouth NHS Trust, Plymouth, United Kingdom
| | - Cherith Wood
- Cardiology Department, Derriford Hospital, University Hospitals Plymouth NHS Trust, Plymouth, United Kingdom
| | - Gurpreet Dhillon
- Cardiology Department, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom
| | - Ross J Hunter
- Cardiology Department, St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom
| | - Phang Boon Lim
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Nicholas W F Linton
- Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom; Imperial Centre for Cardiac Engineering, Imperial College London, London, United Kingdom; Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Prapa Kanagaratnam
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Cardiology Department, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom; Imperial Centre for Cardiac Engineering, Imperial College London, London, United Kingdom.
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8
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Slater NR, Murphy KR, Sikkel MB. VT storm in long QT resulting from COVID-19 vaccine allergy treated with epinephrine. Eur Heart J 2021; 43:1176. [PMID: 34791122 DOI: 10.1093/eurheartj/ehab748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 10/17/2021] [Indexed: 11/14/2022] Open
Affiliation(s)
- Nicholas R Slater
- Department of Medicine, University of British Columbia, Royal Jubilee Hospital, Coronation Annex, 1952 Bay Street, Victoria, BC V8R 1JB, Canada
| | - Kyle R Murphy
- Department of Medicine, University of British Columbia, Royal Jubilee Hospital, Coronation Annex, 1952 Bay Street, Victoria, BC V8R 1JB, Canada.,Division of Critical Care Medicine, University of British Columbia, Royal Jubilee Hospital, Coronation Annex, 1952 Bay Street, Victoria, BC V8R 1JB, Canada
| | - Markus B Sikkel
- Division of Cardiology, University of British Columbia, Royal Jubilee Hospital, Coronation Annex, 1952 Bay Street, Victoria, BC V8R 1JB, Canada.,Division of Medical Sciences, University of Victoria, PO Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada
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9
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Hartley A, Shalhoub J, Ng FS, Krahn AD, Laksman Z, Andrade JG, Deyell MW, Kanagaratnam P, Sikkel MB. Size matters in atrial fibrillation: the underestimated importance of reduction of contiguous electrical mass underlying the effectiveness of catheter ablation. Europace 2021; 23:1698-1707. [PMID: 33948648 PMCID: PMC8576280 DOI: 10.1093/europace/euab078] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/22/2021] [Indexed: 11/13/2022] Open
Abstract
Evidence has accumulated over the last century of the importance of a critical electrical mass in sustaining atrial fibrillation (AF). AF ablation certainly reduces electrically contiguous atrial mass, but this is not widely accepted to be an important part of its mechanism of action. In this article, we review data showing that atrial size is correlated in many settings with AF propensity. Larger mammals are more likely to exhibit AF. This is seen both in the natural world and in animal models, where it is much easier to create a goat model than a mouse model of AF, for example. This also extends to humans-athletes, taller people, and obese individuals all have large atria and are more likely to exhibit AF. Within an individual, risk factors such as hypertension, valvular disease and ischaemia can enlarge the atrium and increase the risk of AF. With respect to AF ablation, we explore how variations in ablation strategy and the relative effectiveness of these strategies may suggest that a reduction in electrical atrial mass is an important mechanism of action. We counter this with examples in which there is no doubt that mass reduction is less important than competing theories such as ganglionated plexus ablation. We conclude that, when considering future strategies for the ablative therapy of AF, it is important not to discount the possibility that contiguous electrical mass reduction is the most important mechanism despite the disappointing consequence being that enhancing success rates in AF ablation may involve greater tissue destruction.
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Affiliation(s)
- Adam Hartley
- National Heart and Lung Institute,Imperial College London, London, UK
| | - Joseph Shalhoub
- National Heart and Lung Institute,Imperial College London, London, UK
| | - Fu Siong Ng
- National Heart and Lung Institute,Imperial College London, London, UK
| | - Andrew D Krahn
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
| | - Zachary Laksman
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
| | - Jason G Andrade
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
| | - Marc W Deyell
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
| | | | - Markus B Sikkel
- Division of Cardiology, University of British Columbia, 740 Hillside Ave, Vancouver, BC V8T 1Z4, Canada
- Division of Medical Sciences, University of Victoria, Victoria, Canada
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10
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Barker M, Bilal Iqbal M, Shetty K, Sikkel MB. How to escape a catastrophic myocardial rupture by a whisker. Eur Heart J 2021; 43:349. [PMID: 34529774 DOI: 10.1093/eurheartj/ehab641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Indexed: 11/14/2022] Open
Affiliation(s)
- Madeleine Barker
- Center for Cardiovascular Innovation, University of British Columbia, 9th Floor, 2775 Laurel Street, Vancouver, BC V5Z1M9, Canada.,Division of Cardiology, University of British Columbia, 9th Floor 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada
| | - M Bilal Iqbal
- Center for Cardiovascular Innovation, University of British Columbia, 9th Floor, 2775 Laurel Street, Vancouver, BC V5Z1M9, Canada.,Division of Cardiology, University of British Columbia, 9th Floor 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada.,Division of Cardiology, Royal Jubilee Hospital, 1952 Bay Street, Victoria, BC, V8R 1J8, Canada
| | - Karan Shetty
- Division of Cardiology, Royal Jubilee Hospital, 1952 Bay Street, Victoria, BC, V8R 1J8, Canada
| | - Markus B Sikkel
- Center for Cardiovascular Innovation, University of British Columbia, 9th Floor, 2775 Laurel Street, Vancouver, BC V5Z1M9, Canada.,Division of Cardiology, University of British Columbia, 9th Floor 2775 Laurel Street, Vancouver, BC V5Z 1M9, Canada.,Division of Cardiology, Royal Jubilee Hospital, 1952 Bay Street, Victoria, BC, V8R 1J8, Canada.,Division of Medical Sciences, University of Victoria, 3800 Finnerty Rd, Victoria, BC, V8P 5C2, Canada
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11
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Al-Khayatt BM, Salciccioli JD, Marshall DC, Krahn AD, Shalhoub J, Sikkel MB. Paradoxical impact of socioeconomic factors on outcome of atrial fibrillation in Europe: trends in incidence and mortality from atrial fibrillation. Eur Heart J 2021; 42:847-857. [PMID: 33495788 DOI: 10.1093/eurheartj/ehaa1077] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/01/2020] [Accepted: 12/16/2020] [Indexed: 12/28/2022] Open
Abstract
AIMS The aim of this study was to understand the changing trends in atrial fibrillation (AF) incidence and mortality across Europe from 1990 to 2017, and how socioeconomic factors and sex differences play a role. METHODS AND RESULTS We performed a temporal analysis of data from the 2017 Global Burden of Disease Database for 20 countries across Europe using Joinpoint regression analysis. Age-adjusted incidence, mortality, and mortality-to-incidence ratios (MIRs) to approximate case fatality rate are presented. Incidence and mortality trends were heterogenous throughout Europe, with Austria, Denmark, and Sweden experiencing peaks in incidence in the middle of the study period. Mortality rates were higher in wealthier countries with the highest being Sweden for both men and women (8.83 and 8.88 per 100 000, respectively) in 2017. MIRs were higher in women in all countries studied, with the disparity increasing the most over time in Germany (43.6% higher in women vs. men in 1990 to 74.5% higher in women in 2017). CONCLUSION AF incidence and mortality across Europe did not show a general trend, but unique patterns for some nations were observed. Higher mortality rates were observed in wealthier countries, potentially secondary to a survivor effect where patients survive long enough to suffer from AF and its complications. Outcomes for women with AF were worse than men, represented by higher MIRs. This suggests that there is widespread healthcare inequality between the sexes across Europe, or that there are biological differences between them in terms of their risk of adverse outcomes from AF.
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Affiliation(s)
- Becker M Al-Khayatt
- Cardiothoracic Intensive Care, Department of Intensive Care Medicine, St George's University Hospital, 1st Floor, Atkinson Morley Wing, Blackshaw Road, London SW17 0QT, UK
| | | | - Dominic C Marshall
- Critical Care Research Group, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Andrew D Krahn
- Division of Cardiology, University of British Columbia, Vancouver, Canada
| | - Joseph Shalhoub
- Imperial Vascular Unit, Imperial College Healthcare NHS Trust, London, UK.,Academic Section of Vascular Surgery, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Markus B Sikkel
- Division of Cardiology, University of British Columbia, Vancouver, Canada.,Royal Jubilee Hospital, Vancouver, Canada.,Division of Medical Sciences, University of Victoria, Victoria, Canada
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12
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Sandler B, Kim MY, Sikkel MB, Malcolme-Lawes L, Koa-Wing M, Whinnett ZI, Coyle C, Linton NWF, Lim PB, Kanagaratnam P. Targeting the ectopy-triggering ganglionated plexuses without pulmonary vein isolation prevents atrial fibrillation. J Cardiovasc Electrophysiol 2021; 32:235-244. [PMID: 33421265 PMCID: PMC8611799 DOI: 10.1111/jce.14870] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/24/2020] [Accepted: 12/05/2020] [Indexed: 01/19/2023]
Abstract
BACKGROUND Ganglionated plexuses (GPs) are implicated in atrial fibrillation (AF). Endocardial high-frequency stimulation (HFS) delivered within the local atrial refractory period can trigger ectopy and AF from specific GP sites (ET-GP). The aim of this study was to understand the role of ET-GP ablation in the treatment of AF. METHODS Patients with paroxysmal AF indicated for ablation were recruited. HFS mapping was performed globally around the left atrium to identify ET-GP. ET-GP was defined as atrial ectopy or atrial arrhythmia triggered by HFS. All ET-GP were ablated, and PVs were left electrically connected. Outcomes were compared with a control group receiving pulmonary vein isolation (PVI). Patients were followed-up for 12 months with multiple 48-h Holter ECGs. Primary endpoint was ≥30 s AF/atrial tachycardia in ECGs. RESULTS In total, 67 patients were recruited and randomized to ET-GP ablation (n = 39) or PVI (n = 28). In the ET-GP ablation group, 103 ± 28 HFS sites were tested per patient, identifying 21 ± 10 (20%) GPs. ET-GP ablation used 23.3 ± 4.1 kWs total radiofrequency (RF) energy per patient, compared with 55.7 ± 22.7 kWs in PVI (p = <.0001). Duration of procedure was 3.7 ± 1.0 and 3.3 ± 0.7 h in ET-GP ablation group and PVI, respectively (p = .07). Follow-up at 12 months showed that 61% and 49% were free from ≥30 s of AF/AT with PVI and ET-GP ablation respectively (log-rank p = .27). CONCLUSIONS It is feasible to perform detailed global functional mapping with HFS and ablate ET-GP to prevent AF. This provides direct evidence that ET-GPs are part of the AF mechanism. The lower RF requirement implies that ET-GP targets the AF pathway more specifically.
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Affiliation(s)
- Belinda Sandler
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Min-Young Kim
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Markus B Sikkel
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Louisa Malcolme-Lawes
- Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Michael Koa-Wing
- Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Zachary I Whinnett
- Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Clare Coyle
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Nick W F Linton
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Phang B Lim
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Prapa Kanagaratnam
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
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13
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Sau A, Al-Aidarous S, Howard J, Shalhoub J, Sohaib A, Shun-Shin M, Novak PG, Leather R, Sterns LD, Lane C, Kanagaratnam P, Peters NS, Francis DP, Sikkel MB. Optimum lesion set and predictors of outcome in persistent atrial fibrillation ablation: a meta-regression analysis. Europace 2020; 21:1176-1184. [PMID: 31071213 DOI: 10.1093/europace/euz108] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 03/27/2019] [Indexed: 11/15/2022] Open
Abstract
AIMS Ablation of persistent atrial fibrillation (PsAF) has been performed by many techniques with varying success rates. This may be due to ablation techniques, patient demographics, comorbidities, and trial design. We conducted a meta-regression of studies of PsAF ablation to elucidate the factors affecting atrial fibrillation (AF) recurrence. METHODS AND RESULTS Databases were searched for prospective studies of PsAF ablation. A meta-regression was performed. Fifty-eight studies (6767 patients) were included. Complex fractionated atrial electrogram (CFAE) ablation reduced freedom from AF by 8.9% [95% confidence interval (CI) -15 to -2.3, P = 0.009). Left atrial appendage [LAA isolation (three study arms)] increased freedom from AF by 39.5% (95% CI 9.1-78.4, P = 0.008). Posterior wall isolation (PWI) (eight study arms) increased freedom from AF by 19.4% (95% CI 3.3-38.1, P = 0.017). Linear ablation or ganglionated plexi ablation resulted in no significant effect on freedom from AF. More extensive ablation increased intraprocedural AF termination; however, intraprocedural AF termination was not associated with improved outcomes. Increased left atrial diameter was associated with a reduction in freedom from AF by 4% (95% CI -6.8% to -1.1%, P = 0.007) for every 1 mm increase in diameter. CONCLUSION Linear ablation, PWI, and CFAE ablation improves intraprocedural AF termination, but such termination does not predict better long-term outcomes. Study arms including PWI or LAA isolation in the lesion set were associated with improved outcomes in terms of freedom from AF; however, further randomized trials are required before these can be routinely recommended. Left atrial size is the most important marker of AF chronicity influencing outcomes.
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Affiliation(s)
- Arunashis Sau
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK
| | - Sayed Al-Aidarous
- Department of Cardiology, Royal Brompton and Harefield NHS Foundation Trust, London, UK
| | - James Howard
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Joseph Shalhoub
- Department of Surgery and Cancer, Imperial College London, London, UK
| | - Afzal Sohaib
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK
| | - Matthew Shun-Shin
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Paul G Novak
- Department of Cardiology, Royal Jubilee Hospital, Victoria, 1952 Bay St, British Columbia, Canada
| | - Rick Leather
- Department of Cardiology, Royal Jubilee Hospital, Victoria, 1952 Bay St, British Columbia, Canada
| | - Laurence D Sterns
- Department of Cardiology, Royal Jubilee Hospital, Victoria, 1952 Bay St, British Columbia, Canada
| | - Christopher Lane
- Department of Cardiology, Royal Jubilee Hospital, Victoria, 1952 Bay St, British Columbia, Canada
| | - Prapa Kanagaratnam
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Nicholas S Peters
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Darrel P Francis
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Markus B Sikkel
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK.,Department of Cardiology, Royal Jubilee Hospital, Victoria, 1952 Bay St, British Columbia, Canada
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14
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Kim MY, Sandler BC, Sikkel MB, Cantwell CD, Leong KM, Luther V, Malcolme-Lawes L, Koa-Wing M, Ng FS, Qureshi N, Sohaib A, Whinnett ZI, Fudge M, Lim E, Todd M, Wright I, Peters NS, Lim PB, Linton NWF, Kanagaratnam P. Anatomical Distribution of Ectopy-Triggering Plexuses in Patients With Atrial Fibrillation. Circ Arrhythm Electrophysiol 2020; 13:e008715. [PMID: 32718187 DOI: 10.1161/circep.120.008715] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Min-Young Kim
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom.,Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom
| | - Belinda C Sandler
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom.,Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom
| | - Markus B Sikkel
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom.,Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Christopher D Cantwell
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom.,Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom
| | - Kevin M Leong
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Vishal Luther
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Louisa Malcolme-Lawes
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Michael Koa-Wing
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Fu Siong Ng
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom.,Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Norman Qureshi
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Afzal Sohaib
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.).,Department of Cardiology, Barts Health NHS Trust, London, United Kingdom (A.S.)
| | - Zachary I Whinnett
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Michael Fudge
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Elaine Lim
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Michelle Todd
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Ian Wright
- Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Nicholas S Peters
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom.,Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Phang Boon Lim
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom.,Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Nicholas W F Linton
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom.,Imperial Centre for Cardiac Engineering (M.-Y.K., B.C.S., M.B.S., C.D.C., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.), Imperial College London, United Kingdom.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, United Kingdom (M.B.S., K.M.L., V.L., L.M.-L., M.K.-W., F.S.N., N.Q., A.S., Z.I.W., M.F., M.F., E.L., M.T., I.W., N.S.P., P.B.L., N.W.F.L.)
| | - Prapa Kanagaratnam
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine (M.-Y.K., B.C.S., M.B.S., C.D.C., F.S.N., N.S.P., P.B.L., N.W.F.L., P.K.), Imperial College London, United Kingdom
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15
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Kim MY, Sandler B, Sikkel MB, Cantwell CD, Leong KM, Luther V, Malcolme-Lawes L, Koa-Wing M, Ng FS, Qureshi N, Sohaib A, Whinnett ZI, Fudge M, Lim E, Todd M, Wright I, Peters NS, Lim PB, Linton NWF, Kanagaratnam P. The ectopy-triggering ganglionated plexuses in atrial fibrillation. Auton Neurosci 2020; 228:102699. [PMID: 32769021 PMCID: PMC7511599 DOI: 10.1016/j.autneu.2020.102699] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 06/27/2020] [Accepted: 07/09/2020] [Indexed: 01/08/2023]
Abstract
BACKGROUND Epicardial ganglionated plexuses (GP) have an important role in the pathogenesis of atrial fibrillation (AF). The relationship between anatomical, histological and functional effects of GP is not well known. We previously described atrioventricular (AV) dissociating GP (AVD-GP) locations. In this study, we hypothesised that ectopy triggering GP (ET-GP) are upstream triggers of atrial ectopy/AF and have different anatomical distribution to AVD-GP. OBJECTIVES We mapped and characterised ET-GP to understand their neural mechanism in AF and anatomical distribution in the left atrium (LA). METHODS 26 patients with paroxysmal AF were recruited. All were paced in the LA with an ablation catheter. High frequency stimulation (HFS) was synchronised to each paced stimulus for delivery within the local atrial refractory period. HFS responses were tagged onto CARTO™ 3D LA geometry. All geometries were transformed onto one reference LA shell. A probability distribution atlas of ET-GP was created. This identified high/low ET-GP probability regions. RESULTS 2302 sites were tested with HFS, identifying 579 (25%) ET-GP. 464 ET-GP were characterised, where 74 (16%) triggered ≥30s AF/AT. Median 97 (IQR 55) sites were tested, identifying 19 (20%) ET-GP per patient. >30% of ET-GP were in the roof, mid-anterior wall, around all PV ostia except in the right inferior PV (RIPV) in the posterior wall. CONCLUSION ET-GP can be identified by endocardial stimulation and their anatomical distribution, in contrast to AVD-GP, would be more likely to be affected by wide antral circumferential ablation. This may contribute to AF ablation outcomes.
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Affiliation(s)
- Min-Young Kim
- Myocardial Function Section, NHLI, Imperial College London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Belinda Sandler
- Myocardial Function Section, NHLI, Imperial College London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Markus B Sikkel
- Myocardial Function Section, NHLI, Imperial College London, UK; Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Christopher D Cantwell
- Myocardial Function Section, NHLI, Imperial College London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Kevin M Leong
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Vishal Luther
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Louisa Malcolme-Lawes
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Michael Koa-Wing
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Fu Siong Ng
- Myocardial Function Section, NHLI, Imperial College London, UK; Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Norman Qureshi
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Afzal Sohaib
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK; Barts Health NHS Trust, UK
| | - Zachary I Whinnett
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Michael Fudge
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Elaine Lim
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Michelle Todd
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Ian Wright
- Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Nicholas S Peters
- Myocardial Function Section, NHLI, Imperial College London, UK; Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Phang Boon Lim
- Myocardial Function Section, NHLI, Imperial College London, UK; Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Nicholas W F Linton
- Myocardial Function Section, NHLI, Imperial College London, UK; Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Prapa Kanagaratnam
- Myocardial Function Section, NHLI, Imperial College London, UK; Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK; Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.
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16
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Sau A, Sikkel MB. Let’s get down to the nitty-gritty in persistent atrial fibrillation: the continuous critical mass of the atria—Authors’ reply. Europace 2019; 21:1280. [DOI: 10.1093/europace/euz201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Arunashis Sau
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Markus B Sikkel
- National Heart and Lung Institute, Imperial College London, London, UK
- Royal Jubilee Hospital, VIC, Canada
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17
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Sau A, Howard JP, Al-Aidarous S, Ferreira-Martins J, Al-Khayatt B, Lim PB, Kanagaratnam P, Whinnett ZI, Peters NS, Sikkel MB, Francis DP, Sohaib SMA. Meta-Analysis of Randomized Controlled Trials of Atrial Fibrillation Ablation With Pulmonary Vein Isolation Versus Without. JACC Clin Electrophysiol 2019; 5:968-976. [PMID: 31439299 PMCID: PMC6709782 DOI: 10.1016/j.jacep.2019.05.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 04/15/2019] [Accepted: 05/17/2019] [Indexed: 01/09/2023]
Abstract
Objectives This meta-analysis examined the ability of pulmonary vein isolation (PVI) to prevent atrial fibrillation in randomized controlled trials (RCTs) in which the patients not receiving PVI nevertheless underwent a procedure. Background PVI is a commonly used procedure for the treatment of atrial fibrillation (AF), and its efficacy has usually been judged against therapy with anti-arrhythmic drugs in open-label trials. There have been several RCTs of AF ablation in which both arms received an ablation, but the difference between the treatment arms was inclusion or omission of PVI. These trials of an ablation strategy with PVI versus an ablation strategy without PVI may provide a more rigorous method for evaluating the efficacy of PVI. Methods Medline and Cochrane databases were searched for RCTs comparing ablation including PVI with ablation excluding PVI. The primary efficacy endpoint was freedom from atrial fibrillation (AF) and atrial tachycardia at 12 months. A random-effects meta-analysis was performed using the restricted maximum likelihood estimator. Results Overall, 6 studies (n = 610) met inclusion criteria. AF recurrence was significantly lower with an ablation including PVI than an ablation without PVI (RR: 0.54; 95% confidence interval [CI]: 0.33 to 0.89; p = 0.0147; I2 = 79.7%). Neither the type of AF (p = 0.48) nor the type of non-PVI ablation (p = 0.21) was a significant moderator of the effect size. In 3 trials the non-PVI ablation procedure was performed in both arms, whereas PVI was performed in only 1 arm. In these studies, AF recurrence was significantly lower when PVI was included (RR: 0.32; 95% CI: 0.14 to 0.73; p = 0.007, I2 78%). Conclusions In RCTs where both arms received an ablation, and therefore an expectation amongst patients and doctors of benefit, being randomized to PVI had a striking effect, reducing AF recurrence by a half.
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Affiliation(s)
- Arunashis Sau
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - James P Howard
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, United Kingdom
| | - Sayed Al-Aidarous
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiology, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom
| | | | - Becker Al-Khayatt
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - P Boon Lim
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, United Kingdom
| | - Prapa Kanagaratnam
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, United Kingdom
| | - Zachary I Whinnett
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, United Kingdom
| | - Nicholas S Peters
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, United Kingdom
| | - Markus B Sikkel
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiology, Royal Jubilee Hospital, Victoria, Canada
| | - Darrel P Francis
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, United Kingdom
| | - S M Afzal Sohaib
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Cardiac Electrophysiology, Bart's Heart Centre, St Bartholomew's Hospital, London, United Kingdom; Department of Cardiology, King George Hospital, Ilford, United Kingdom.
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18
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Perbellini F, Watson SA, Scigliano M, Alayoubi S, Tkach S, Bardi I, Quaife N, Kane C, Dufton NP, Simon A, Sikkel MB, Faggian G, Randi AM, Gorelik J, Harding SE, Terracciano CM. Investigation of cardiac fibroblasts using myocardial slices. Cardiovasc Res 2019; 114:77-89. [PMID: 29016704 PMCID: PMC5852538 DOI: 10.1093/cvr/cvx152] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 08/17/2017] [Indexed: 12/15/2022] Open
Abstract
Aims Cardiac fibroblasts (CFs) are considered the principal regulators of cardiac fibrosis. Factors that influence CF activity are difficult to determine. When isolated and cultured in vitro, CFs undergo rapid phenotypic changes including increased expression of α-SMA. Here we describe a new model to study CFs and their response to pharmacological and mechanical stimuli using in vitro cultured mouse, dog and human myocardial slices. Methods and results Unloading of myocardial slices induced CF proliferation without α-SMA expression up to 7 days in culture. CFs migrating onto the culture plastic support or cultured on glass expressed αSMA within 3 days. The cells on the slice remained αSMA(−) despite transforming growth factor-β (20 ng/ml) or angiotensin II (200 µM) stimulation. When diastolic load was applied to myocardial slices using A-shaped stretchers, CF proliferation was significantly prevented at Days 3 and 7 (P < 0.001). Conclusions Myocardial slices allow the study of CFs in a multicellular environment and may be used to effectively study mechanisms of cardiac fibrosis and potential targets.
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Affiliation(s)
- Filippo Perbellini
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Samuel A Watson
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | | | - Samha Alayoubi
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Sebastian Tkach
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Ifigeneia Bardi
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Nicholas Quaife
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Christopher Kane
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Neil P Dufton
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - André Simon
- Department of Cardiothoracic Transplantation and Mechanical Circulatory Support, Royal Brompton and Harefield NHS Foundation Trust, Harefield, UK
| | - Markus B Sikkel
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Giuseppe Faggian
- Department of Cardiac Surgery, University of Verona, Verona, Italy
| | - Anna M Randi
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Julia Gorelik
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Sian E Harding
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
| | - Cesare M Terracciano
- Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London W12?0NN, UK
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19
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Ferreira‐Martins J, Howard J, Al‐Khayatt B, Shalhoub J, Sohaib A, Shun‐Shin MJ, Novak PG, Leather R, Sterns LD, Lane C, Lim PB, Kanagaratnam P, Peters NS, Francis DP, Sikkel MB. Outcomes of paroxysmal atrial fibrillation ablation studies are affected more by study design and patient mix than ablation technique. J Cardiovasc Electrophysiol 2018; 29:1471-1479. [DOI: 10.1111/jce.13745] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 07/16/2018] [Accepted: 07/31/2018] [Indexed: 11/28/2022]
Affiliation(s)
- João Ferreira‐Martins
- Department of CardiologyImperial College Healthcare NHS Trust, Hammersmith HospitalLondon UK
| | - James Howard
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College LondonLondon UK
| | - Becker Al‐Khayatt
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College LondonLondon UK
| | - Joseph Shalhoub
- Department of Surgery and CancerImperial College LondonLondon UK
| | - Afzal Sohaib
- Department of CardiologyImperial College Healthcare NHS Trust, Hammersmith HospitalLondon UK
| | - Matthew J. Shun‐Shin
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College LondonLondon UK
| | - Paul G. Novak
- Department of MedicineRoyal Jubilee HospitalVictoria Canada
| | - Rick Leather
- Department of MedicineRoyal Jubilee HospitalVictoria Canada
| | | | | | - Phang Boon Lim
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College LondonLondon UK
- Department of CardiologyImperial College Healthcare NHS Trust, Hammersmith HospitalLondon UK
| | - Prapa Kanagaratnam
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College LondonLondon UK
- Department of CardiologyImperial College Healthcare NHS Trust, Hammersmith HospitalLondon UK
| | - Nicholas S. Peters
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College LondonLondon UK
- Department of CardiologyImperial College Healthcare NHS Trust, Hammersmith HospitalLondon UK
| | - Darrel P. Francis
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College LondonLondon UK
- Department of CardiologyImperial College Healthcare NHS Trust, Hammersmith HospitalLondon UK
| | - Markus B. Sikkel
- Department of MedicineRoyal Jubilee HospitalVictoria Canada
- International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College LondonLondon UK
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20
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Kim MY, Sikkel MB, Hunter RJ, Haywood GA, Tomlinson DR, Tayebjee MH, Ali RL, Cantwell CD, Gonna H, Sandler BC, Lim E, Furniss G, Panagopoulos D, Begg G, Dhillon G, Hill NJ, O'Neill J, Francis DP, Lim PB, Peters NS, Linton NWF, Kanagaratnam P. A novel approach to mapping the atrial ganglionated plexus network by generating a distribution probability atlas. J Cardiovasc Electrophysiol 2018; 29:1624-1634. [PMID: 30168232 PMCID: PMC6369684 DOI: 10.1111/jce.13723] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/16/2018] [Accepted: 08/23/2018] [Indexed: 11/27/2022]
Abstract
Introduction The ganglionated plexuses (GPs) of the intrinsic cardiac autonomic system are implicated in arrhythmogenesis. GP localization by stimulation of the epicardial fat pads to produce atrioventricular dissociating (AVD) effects is well described. We determined the anatomical distribution of the left atrial GPs that influence atrioventricular (AV) dissociation. Methods and Results High frequency stimulation was delivered through a Smart‐Touch catheter in the left atrium of patients undergoing atrial fibrillation (AF) ablation. Three dimensional locations of points tested throughout the entire chamber were recorded on the CARTO™ system. Impact on the AV conduction was categorized as ventricular asystole, bradycardia, or no effect. CARTO maps were exported, registered, and transformed onto a reference left atrial geometry using a custom software, enabling data from multiple patients to be overlaid. In 28 patients, 2108 locations were tested and 283 sites (13%) demonstrated (AVD‐GP) effects. There were 10 AVD‐GPs (interquartile range, 11.5) per patient. Eighty percent (226) produced asystole and 20% (57) showed bradycardia. The distribution of the two groups was very similar. Highest probability of AVD‐GPs (>20%) was identified in: inferoseptal portion (41%) and right inferior pulmonary vein base (30%) of the posterior wall, right superior pulmonary vein antrum (31%). Conclusion It is feasible to map the entire left atrium for AVD‐GPs before AF ablation. Aggregated data from multiple patients, producing a distribution probability atlas of AVD‐GPs, identified three regions with a higher likelihood for finding AVD‐GPs and these matched the histological descriptions. This approach could be used to better characterize the autonomic network.
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Affiliation(s)
- Min-Young Kim
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Markus B Sikkel
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Ross J Hunter
- Department of Cardiology, The Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Guy A Haywood
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - David R Tomlinson
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Muzahir H Tayebjee
- Department of Cardiology, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Rheeda L Ali
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Chris D Cantwell
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Hanney Gonna
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Belinda C Sandler
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK
| | - Elaine Lim
- Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Guy Furniss
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Dimitrios Panagopoulos
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Gordon Begg
- Department of Cardiology, Derriford Hospital, Plymouth Hospitals NHS Trust, Plymouth, UK
| | - Gurpreet Dhillon
- Department of Cardiology, The Barts Heart Centre, St Bartholomew's Hospital, Barts Health NHS Trust, London, UK
| | - Nicola J Hill
- Department of Cardiology, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - James O'Neill
- Department of Cardiology, Leeds General Infirmary, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - Darrel P Francis
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Phang Boon Lim
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Nicholas S Peters
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Nick W F Linton
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
| | - Prapa Kanagaratnam
- Myocardial Function Section, Imperial Centre for Translational and Experimental Medicine, Imperial College London, London, UK.,Imperial Centre for Cardiac Engineering, Imperial College London, London, UK.,Department of Cardiology, Imperial College Healthcare NHS Trust, London, UK
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21
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Sikkel MB, Luther V, Sau A, Guerrero F, Ng FS, Lim PB. High-Density Electroanatomical Mapping to Identify Point of Epicardial to Endocardial Breakthrough in Perimitral Flutter. JACC Clin Electrophysiol 2018; 3:637-639. [PMID: 29759439 DOI: 10.1016/j.jacep.2016.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/20/2016] [Accepted: 11/28/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Markus B Sikkel
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Electrophysiology, Imperial College Healthcare National Health Service Trust, Hammersmith Hospital, London, United Kingdom.
| | - Vishal Luther
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Electrophysiology, Imperial College Healthcare National Health Service Trust, Hammersmith Hospital, London, United Kingdom
| | - Arunashis Sau
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | | | - Fu Siong Ng
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Phang Boon Lim
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Department of Electrophysiology, Imperial College Healthcare National Health Service Trust, Hammersmith Hospital, London, United Kingdom
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22
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Williams AJ, Bannister ML, Thomas NL, Sikkel MB, Mukherjee S, Maxwell C, MacLeod KT, George CH. Questioning flecainide's mechanism of action in the treatment of catecholaminergic polymorphic ventricular tachycardia. J Physiol 2018; 594:6431-6432. [PMID: 27800620 PMCID: PMC5088245 DOI: 10.1113/jp272497] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- Alan J Williams
- School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK.
| | | | - N Lowri Thomas
- School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Markus B Sikkel
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, W12 0NN, UK
| | | | - Chloe Maxwell
- School of Medicine, Cardiff University, Cardiff, CF14 4XN, UK
| | - Kenneth T MacLeod
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, W12 0NN, UK
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23
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Sikkel MB, Francis DP, Howard J, Gordon F, Rowlands C, Peters NS, Lyon AR, Harding SE, MacLeod KT. Hierarchical statistical techniques are necessary to draw reliable conclusions from analysis of isolated cardiomyocyte studies. Cardiovasc Res 2017; 113:1743-1752. [PMID: 29016722 PMCID: PMC5852514 DOI: 10.1093/cvr/cvx151] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/27/2017] [Accepted: 08/29/2017] [Indexed: 02/01/2023] Open
Abstract
AIMS It is generally accepted that post-MI heart failure (HF) changes a variety of aspects of sarcoplasmic reticular Ca2+ fluxes but for some aspects there is disagreement over whether there is an increase or decrease. The commonest statistical approach is to treat data collected from each cell as independent, even though they are really clustered with multiple likely similar cells from each heart. In this study, we test whether this statistical assumption of independence can lead the investigator to draw conclusions that would be considered erroneous if the analysis handled clustering with specific statistical techniques (hierarchical tests). METHODS AND RESULTS Ca2+ transients were recorded in cells loaded with Fura-2AM and sparks were recorded in cells loaded with Fluo-4AM. Data were analysed twice, once with the common statistical approach (assumption of independence) and once with hierarchical statistical methodologies designed to allow for any clustering. The statistical tests found that there was significant hierarchical clustering. This caused the common statistical approach to underestimate the standard error and report artificially small P values. For example, this would have led to the erroneous conclusion that time to 50% peak transient amplitude was significantly prolonged in HF. Spark analysis showed clustering, both within each cell and also within each rat, for morphological variables. This means that a three-level hierarchical model is sometimes required for such measures. Standard statistical methodologies, if used instead, erroneously suggest that spark amplitude is significantly greater in HF and spark duration is reduced in HF. CONCLUSION Ca2+ fluxes in isolated cardiomyocytes show so much clustering that the common statistical approach that assumes independence of each data point will frequently give the false appearance of statistically significant changes. Hierarchical statistical methodologies need a little more effort, but are necessary for reliable conclusions. We present cost-free simple tools for performing these analyses.
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Affiliation(s)
- Markus B Sikkel
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
- Department of Electrophysiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Darrel P Francis
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
| | - James Howard
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
| | - Fabiana Gordon
- Statistics Advisory Service, Imperial College London, London, UK
| | - Christina Rowlands
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
| | - Nicholas S Peters
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
- Department of Electrophysiology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
| | - Alexander R Lyon
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
- Department of Cardiology, Royal Brompton Hospital, London, UK
| | - Sian E Harding
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
| | - Kenneth T MacLeod
- Myocardial Function Section, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute, Imperial College London, Hammersmith Campus, Du Cane Road, London, UK
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Kim MY, Sikkel MB, Hunter R, Haywood G, Tomlinson D, Furniss G, Panagopoulos D, Tayebjee M, Begg G, Ali R, Cantwell C, Gonna H, Sandler B, Lim ZL, Lim PB, Peters NS, Linton N, Kanagaratnam P. 53Generation of the first functional map of left atrial ganglionated plexus sites that induce AV nodal bradycardia. Europace 2017. [DOI: 10.1093/europace/eux283.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sau A, Sikkel MB, Luther V, Wright I, Guerrero F, Koa-Wing M, Lefroy D, Linton N, Qureshi N, Whinnett Z, Lim PB, Kanagaratnam P, Peters N, Davies DW. 148The sawtooth EKG pattern of typical atrial flutter is not related to differences in conduction velocity around the flutter circuit. Europace 2017. [DOI: 10.1093/europace/eux283.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Sau A, Sikkel MB, Luther V, Wright I, Guerrero F, Koa-Wing M, Lefroy D, Linton N, Qureshi N, Whinnett Z, Lim PB, Kanagaratnam P, Peters NS, Davies DW. The sawtooth EKG pattern of typical atrial flutter is not related to slow conduction velocity at the cavotricuspid isthmus. J Cardiovasc Electrophysiol 2017; 28:1445-1453. [DOI: 10.1111/jce.13323] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 08/13/2017] [Accepted: 08/15/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Arunashis Sau
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Markus B. Sikkel
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Vishal Luther
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Ian Wright
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | | | - Michael Koa-Wing
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - David Lefroy
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Nicholas Linton
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Norman Qureshi
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Zachary Whinnett
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Phang Boon Lim
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Prapa Kanagaratnam
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - Nicholas S. Peters
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
| | - D. Wyn Davies
- Imperial Centre for Translational and Experimental Medicine; Imperial College London; London UK
- Department of Cardiology; Imperial College Healthcare NHS Trust; London UK
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Sikkel MB, Kumar S, Maioli V, Rowlands C, Gordon F, Harding SE, Lyon AR, MacLeod KT, Dunsby C. Erratum: High speed sCMOS-based oblique plane microscopy applied to the study of calcium dynamics in cardiac myocytes: [J. Biophotonics 9, No. 3, 311-323 (2016)]. J Biophotonics 2017; 10:744-745. [PMID: 28498628 PMCID: PMC6885920 DOI: 10.1002/jbio.201700062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In the article by M.B. Sikkel et al. (doi: 10.1002/jbio.201500193), published in J. Biophotonics 9, 311-323 (2016), an error occurred in the computer code that was used to generate Figure 3. This erratum is published to correct Figure 3, the calculated value of tgeom and the experimentally determined value of toptics in the text of the article.
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Sanchez-Alonso JL, Bhargava A, O'Hara T, Glukhov AV, Schobesberger S, Bhogal N, Sikkel MB, Mansfield C, Korchev YE, Lyon AR, Punjabi PP, Nikolaev VO, Trayanova NA, Gorelik J. Microdomain-Specific Modulation of L-Type Calcium Channels Leads to Triggered Ventricular Arrhythmia in Heart Failure. Circ Res 2016; 119:944-55. [PMID: 27572487 PMCID: PMC5045818 DOI: 10.1161/circresaha.116.308698] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 08/24/2016] [Indexed: 11/22/2022]
Abstract
Supplemental Digital Content is available in the text. Rationale: Disruption in subcellular targeting of Ca2+ signaling complexes secondary to changes in cardiac myocyte structure may contribute to the pathophysiology of a variety of cardiac diseases, including heart failure (HF) and certain arrhythmias. Objective: To explore microdomain-targeted remodeling of ventricular L-type Ca2+ channels (LTCCs) in HF. Methods and Results: Super-resolution scanning patch-clamp, confocal and fluorescence microscopy were used to explore the distribution of single LTCCs in different membrane microdomains of nonfailing and failing human and rat ventricular myocytes. Disruption of membrane structure in both species led to the redistribution of functional LTCCs from their canonical location in transversal tubules (T-tubules) to the non-native crest of the sarcolemma, where their open probability was dramatically increased (0.034±0.011 versus 0.154±0.027, P<0.001). High open probability was linked to enhance calcium–calmodulin kinase II–mediated phosphorylation in non-native microdomains and resulted in an elevated ICa,L window current, which contributed to the development of early afterdepolarizations. A novel model of LTCC function in HF was developed; after its validation with experimental data, the model was used to ascertain how HF-induced T-tubule loss led to altered LTCC function and early afterdepolarizations. The HF myocyte model was then implemented in a 3-dimensional left ventricle model, demonstrating that such early afterdepolarizations can propagate and initiate reentrant arrhythmias. Conclusions: Microdomain-targeted remodeling of LTCC properties is an important event in pathways that may contribute to ventricular arrhythmogenesis in the settings of HF-associated remodeling. This extends beyond the classical concept of electric remodeling in HF and adds a new dimension to cardiovascular disease.
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Affiliation(s)
- Jose L Sanchez-Alonso
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Anamika Bhargava
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Thomas O'Hara
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Alexey V Glukhov
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Sophie Schobesberger
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Navneet Bhogal
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Markus B Sikkel
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Catherine Mansfield
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Yuri E Korchev
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Alexander R Lyon
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Prakash P Punjabi
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Viacheslav O Nikolaev
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Natalia A Trayanova
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.)
| | - Julia Gorelik
- From the Department of Cardiovascular Sciences, Imperial Centre for Translational and Experimental Medicine, National Heart and Lung Institute (J.L.S.-A., A.B., A.V.G., S.S., N.B., M.B.S., C.M., A.R.L., P.P.P., J.G.), Department of Medicine (Y.E.K.), and Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute (P.P.P.), Imperial College London, United Kingdom; Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD (T.O., N.A.T.); NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom (A.R.L.); Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Hamburg, Germany (S.S., V.O.N.); and Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Telangana, India (A.B.).
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Luther V, Sikkel MB, Wright I, Faulkner M, Qureshi N, Lefroy DC. A Collapsed Sportsman With a Shock Advised in Sinus Rhythm: The Importance of Automated External Defibrillator Rhythm Strip Retrieval Prior to Defibrillator Implantation. Circ Arrhythm Electrophysiol 2016; 9:e003914. [PMID: 26987568 DOI: 10.1161/circep.116.003914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Vishal Luther
- From the Department of Cardiac Electrophysiology, Imperial College Healthcare NHS Trust (V.L., M.B.S., I.W., N.Q., D.C.L.) and London Ambulance Service (M.F.), London, United Kingdom.
| | - Markus B Sikkel
- From the Department of Cardiac Electrophysiology, Imperial College Healthcare NHS Trust (V.L., M.B.S., I.W., N.Q., D.C.L.) and London Ambulance Service (M.F.), London, United Kingdom
| | - Ian Wright
- From the Department of Cardiac Electrophysiology, Imperial College Healthcare NHS Trust (V.L., M.B.S., I.W., N.Q., D.C.L.) and London Ambulance Service (M.F.), London, United Kingdom
| | - Mark Faulkner
- From the Department of Cardiac Electrophysiology, Imperial College Healthcare NHS Trust (V.L., M.B.S., I.W., N.Q., D.C.L.) and London Ambulance Service (M.F.), London, United Kingdom
| | - Norman Qureshi
- From the Department of Cardiac Electrophysiology, Imperial College Healthcare NHS Trust (V.L., M.B.S., I.W., N.Q., D.C.L.) and London Ambulance Service (M.F.), London, United Kingdom
| | - David C Lefroy
- From the Department of Cardiac Electrophysiology, Imperial College Healthcare NHS Trust (V.L., M.B.S., I.W., N.Q., D.C.L.) and London Ambulance Service (M.F.), London, United Kingdom
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Toepfer CN, Sikkel MB, Caorsi V, Vydyanath A, Torre I, Copeland O, Lyon AR, Marston SB, Luther PK, Macleod KT, West TG, Ferenczi MA. A post-MI power struggle: adaptations in cardiac power occur at the sarcomere level alongside MyBP-C and RLC phosphorylation. Am J Physiol Heart Circ Physiol 2016; 311:H465-75. [PMID: 27233767 PMCID: PMC5005282 DOI: 10.1152/ajpheart.00899.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 05/24/2016] [Indexed: 01/25/2023]
Abstract
Myocardial remodeling in response to chronic myocardial infarction (CMI) progresses through two phases, hypertrophic "compensation" and congestive "decompensation." Nothing is known about the ability of uninfarcted myocardium to produce force, velocity, and power during these clinical phases, even though adaptation in these regions likely drives progression of compensation. We hypothesized that enhanced cross-bridge-level contractility underlies mechanical compensation and is controlled in part by changes in the phosphorylation states of myosin regulatory proteins. We induced CMI in rats by left anterior descending coronary artery ligation. We then measured mechanical performance in permeabilized ventricular trabecula taken distant from the infarct zone and assayed myosin regulatory protein phosphorylation in each individual trabecula. During full activation, the compensated myocardium produced twice as much power and 31% greater isometric force compared with noninfarcted controls. Isometric force during submaximal activations was raised >2.4-fold, while power was 2-fold greater. Electron and confocal microscopy demonstrated that these mechanical changes were not a result of increased density of contractile protein and therefore not an effect of tissue hypertrophy. Hence, sarcomere-level contractile adaptations are key determinants of enhanced trabecular mechanics and of the overall cardiac compensatory response. Phosphorylation of myosin regulatory light chain (RLC) increased and remained elevated post-MI, while phosphorylation of myosin binding protein-C (MyBP-C) was initially depressed but then increased as the hearts became decompensated. These sensitivities to CMI are in accordance with phosphorylation-dependent regulatory roles for RLC and MyBP-C in crossbridge function and with compensatory adaptation in force and power that we observed in post-CMI trabeculae.
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Affiliation(s)
- Christopher N Toepfer
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Laboratory of Molecular Physiology, National Heart and Lung Institute, National Institutes of Health, Bethesda, Maryland;
| | - Markus B Sikkel
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Valentina Caorsi
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Laboratoire Physico-Chimie, UMR168, Institute Curie, Paris, France
| | - Anupama Vydyanath
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Iratxe Torre
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - O'Neal Copeland
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Alexander R Lyon
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Nationa Institute of Health Research Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom
| | - Steven B Marston
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Pradeep K Luther
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Kenneth T Macleod
- Department of Cardiac Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Timothy G West
- Royal Veterinary College London, Structure & Motion Laboratory, North Mymms, United Kingdom; and
| | - Michael A Ferenczi
- Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
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Hartley A, Marshall DC, Salciccioli JD, Sikkel MB, Maruthappu M, Shalhoub J. Trends in Mortality From Ischemic Heart Disease and Cerebrovascular Disease in Europe. Circulation 2016; 133:1916-26. [DOI: 10.1161/circulationaha.115.018931] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 03/18/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Adam Hartley
- From Imperial College London, United Kingdom (A.H., D.C.M., J.D.S., M.B.S., J.S.); and Foundation School, Imperial College London, United Kingdom (M.M.)
| | - Dominic C. Marshall
- From Imperial College London, United Kingdom (A.H., D.C.M., J.D.S., M.B.S., J.S.); and Foundation School, Imperial College London, United Kingdom (M.M.)
| | - Justin D. Salciccioli
- From Imperial College London, United Kingdom (A.H., D.C.M., J.D.S., M.B.S., J.S.); and Foundation School, Imperial College London, United Kingdom (M.M.)
| | - Markus B. Sikkel
- From Imperial College London, United Kingdom (A.H., D.C.M., J.D.S., M.B.S., J.S.); and Foundation School, Imperial College London, United Kingdom (M.M.)
| | - Mahiben Maruthappu
- From Imperial College London, United Kingdom (A.H., D.C.M., J.D.S., M.B.S., J.S.); and Foundation School, Imperial College London, United Kingdom (M.M.)
| | - Joseph Shalhoub
- From Imperial College London, United Kingdom (A.H., D.C.M., J.D.S., M.B.S., J.S.); and Foundation School, Imperial College London, United Kingdom (M.M.)
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Sikkel MB, Kumar S, Maioli V, Rowlands C, Gordon F, Harding SE, Lyon AR, MacLeod KT, Dunsby C. High speed sCMOS-based oblique plane microscopy applied to the study of calcium dynamics in cardiac myocytes. J Biophotonics 2016; 9:311-23. [PMID: 26488431 PMCID: PMC4874460 DOI: 10.1002/jbio.201500193] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 08/28/2015] [Accepted: 09/16/2015] [Indexed: 05/18/2023]
Abstract
Oblique plane microscopy (OPM) is a form of light sheet microscopy that uses a single high numerical aperture microscope objective for both fluorescence excitation and collection. In this paper, measurements of the relative collection efficiency of OPM are presented. An OPM system incorporating two sCMOS cameras is then introduced that enables single isolated cardiac myocytes to be studied continuously for 22 seconds in two dimensions at 667 frames per second with 960 × 200 pixels and for 30 seconds with 960 × 200 × 20 voxels at 25 volumes per second. In both cases OPM is able to record in two spectral channels, enabling intracellular calcium to be studied via the probe Fluo-4 AM simultaneously with the sarcolemma and transverse tubule network via the membrane dye Cellmask Orange. The OPM system was then applied to determine the spatial origin of spontaneous calcium waves for the first time and to measure the cell transverse tubule structure at their point of origin. Further results are presented to demonstrate that the OPM system can also be used to study calcium spark parameters depending on their relationship to the transverse tubule structure.
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Affiliation(s)
- Markus B Sikkel
- Myocardial Function Section, National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Sunil Kumar
- Photonics Group, Department of Physics, Imperial College London, London, United Kingdom
| | - Vincent Maioli
- Photonics Group, Department of Physics, Imperial College London, London, United Kingdom.
| | - Christina Rowlands
- Myocardial Function Section, National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Fabiana Gordon
- Statistics Advisory Service, Imperial College London, London, United Kingdom
| | - Sian E Harding
- Myocardial Function Section, National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Alexander R Lyon
- Myocardial Function Section, National Heart and Lung Institute, Imperial College, London, United Kingdom
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom
| | - Kenneth T MacLeod
- Myocardial Function Section, National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Chris Dunsby
- Photonics Group, Department of Physics, Imperial College London, London, United Kingdom
- Centre for Pathology, Department of Medicine, Imperial College London, United Kingdom
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Glukhov AV, Balycheva M, Sanchez-Alonso JL, Ilkan Z, Alvarez-Laviada A, Bhogal N, Diakonov I, Schobesberger S, Sikkel MB, Bhargava A, Faggian G, Punjabi PP, Houser SR, Gorelik J. Direct Evidence for Microdomain-Specific Localization and Remodeling of Functional L-Type Calcium Channels in Rat and Human Atrial Myocytes. Circulation 2015; 132:2372-84. [PMID: 26450916 PMCID: PMC4689179 DOI: 10.1161/circulationaha.115.018131] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 10/02/2015] [Indexed: 12/27/2022]
Abstract
Supplemental Digital Content is available in the text. Distinct subpopulations of L-type calcium channels (LTCCs) with different functional properties exist in cardiomyocytes. Disruption of cellular structure may affect LTCC in a microdomain-specific manner and contribute to the pathophysiology of cardiac diseases, especially in cells lacking organized transverse tubules (T-tubules) such as atrial myocytes (AMs).
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Affiliation(s)
- Alexey V Glukhov
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Marina Balycheva
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Jose L Sanchez-Alonso
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Zeki Ilkan
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Anita Alvarez-Laviada
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Navneet Bhogal
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Ivan Diakonov
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Sophie Schobesberger
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Markus B Sikkel
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Anamika Bhargava
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Giuseppe Faggian
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Prakash P Punjabi
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Steven R Houser
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.)
| | - Julia Gorelik
- From Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College London, United Kingdom (A.V.G., M.B., J.L.S.-A., Z.I., A.A.-L., N.B., I.D., S.S., M.B.S., A.B., P.P.P., J.G.); University of Verona, School of Medicine, Verona, Italy (M.B., G.F.); Department of Cardiothoracic Surgery, Hammersmith Hospital, National Heart and Lung Institute, Imperial College London, United Kingdom (P.P.P.); and Cardiovascular Research Center and Department of Physiology, Temple University School of Medicine, Philadelphia, PA (S.R.H.).
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Roca-Alonso L, Castellano L, Mills A, Dabrowska AF, Sikkel MB, Pellegrino L, Jacob J, Frampton AE, Krell J, Coombes RC, Harding SE, Lyon AR, Stebbing J. Myocardial MiR-30 downregulation triggered by doxorubicin drives alterations in β-adrenergic signaling and enhances apoptosis. Cell Death Dis 2015; 6:e1754. [PMID: 25950484 PMCID: PMC4669718 DOI: 10.1038/cddis.2015.89] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 12/14/2014] [Accepted: 01/12/2015] [Indexed: 12/22/2022]
Abstract
The use of anthracyclines such as doxorubicin (DOX) has improved outcome in cancer patients, yet associated risks of cardiomyopathy have limited their clinical application. DOX-associated cardiotoxicity is frequently irreversible and typically progresses to heart failure (HF) but our understanding of molecular mechanisms underlying this and essential for development of cardioprotective strategies remains largely obscure. As microRNAs (miRNAs) have been shown to play potent regulatory roles in both cardiovascular disease and cancer, we investigated miRNA changes in DOX-induced HF and the alteration of cellular processes downstream. Myocardial miRNA profiling was performed after DOX-induced injury, either via acute application to isolated cardiomyocytes or via chronic exposure in vivo, and compared with miRNA profiles from remodeled hearts following myocardial infarction. The miR-30 family was downregulated in all three models. We describe here that miR-30 act regulating the β-adrenergic pathway, where preferential β1- and β2-adrenoceptor (β1AR and β2AR) direct inhibition is combined with Giα-2 targeting for fine-tuning. Importantly, we show that miR-30 also target the pro-apoptotic gene BNIP3L/NIX. In aggregate, we demonstrate that high miR-30 levels are protective against DOX toxicity and correlate this in turn with lower reactive oxygen species generation. In addition, we identify GATA-6 as a mediator of DOX-associated reductions in miR-30 expression. In conclusion, we describe that DOX causes acute and sustained miR-30 downregulation in cardiomyocytes via GATA-6. miR-30 overexpression protects cardiac cells from DOX-induced apoptosis, and its maintenance represents a potential cardioprotective and anti-tumorigenic strategy for anthracyclines.
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Affiliation(s)
- L Roca-Alonso
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - L Castellano
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - A Mills
- National Heart and Lung Institute, Imperial College, 4th Floor, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - A F Dabrowska
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - M B Sikkel
- National Heart and Lung Institute, Imperial College, 4th Floor, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - L Pellegrino
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - J Jacob
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - A E Frampton
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
- Hepato-Pancreato-Biliary Surgical Unit, Department of Surgery and Cancer, Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - J Krell
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - R C Coombes
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - S E Harding
- National Heart and Lung Institute, Imperial College, 4th Floor, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
| | - A R Lyon
- National Heart and Lung Institute, Imperial College, 4th Floor, ICTEM, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Imperial college, London SW3 6NP, UK
| | - J Stebbing
- Division of Oncology, Department of Surgery and Cancer, 1st Floor, Imperial Centre for Translational and Experimental Medicine (ICTEM), Imperial College, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
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Bannister ML, Thomas NL, Sikkel MB, Mukherjee S, Maxwell C, MacLeod KT, George CH, Williams AJ. The mechanism of flecainide action in CPVT does not involve a direct effect on RyR2. Circ Res 2015; 116:1324-35. [PMID: 25648700 DOI: 10.1161/circresaha.116.305347] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/03/2015] [Indexed: 12/17/2022]
Abstract
RATIONALE Flecainide, a class 1c antiarrhythmic, has emerged as an effective therapy in preventing arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia (CPVT) refractory to β-adrenergic receptor blockade. It has been proposed that the clinical efficacy of flecainide in CPVT is because of the combined actions of direct blockade of ryanodine receptors (RyR2) and Na(+) channel inhibition. However, there is presently no direct evidence to support the notion that flecainide blocks RyR2 Ca(2+) flux in the physiologically relevant (luminal-to-cytoplasmic) direction. The mechanism of flecainide action remains controversial. OBJECTIVE To examine, in detail, the effect of flecainide on the human RyR2 channel and to establish whether the direct blockade of physiologically relevant RyR2 ion flow by the drug contributes to its therapeutic efficacy in the clinical management of CPVT. METHODS AND RESULTS Using single-channel analysis, we show that, even at supraphysiological concentrations, flecainide did not inhibit the physiologically relevant, luminal-to-cytosolic flux of cations through the channel. Moreover, flecainide did not alter RyR2 channel gating and had negligible effect on the mechanisms responsible for the sarcoplasmic reticulum charge-compensating counter current. Using permeabilized cardiac myocytes to eliminate any contribution of plasmalemmal Na(+) channels to the observed actions of the drug at the cellular level, flecainide did not inhibit RyR2-dependent sarcoplasmic reticulum Ca(2+) release. CONCLUSIONS The principal action of flecainide in CPVT is not via a direct interaction with RyR2. Our data support a model of flecainide action in which Na(+)-dependent modulation of intracellular Ca(2+) handling attenuates RyR2 dysfunction in CPVT.
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Affiliation(s)
- Mark L Bannister
- From the Institute of Molecular and Experimental Medicine, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom (M.L.B., N.L.T., S.M., C.M., C.H.G., A.J.W.); and Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom (M.B.S., K.T.M.)
| | - N Lowri Thomas
- From the Institute of Molecular and Experimental Medicine, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom (M.L.B., N.L.T., S.M., C.M., C.H.G., A.J.W.); and Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom (M.B.S., K.T.M.)
| | - Markus B Sikkel
- From the Institute of Molecular and Experimental Medicine, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom (M.L.B., N.L.T., S.M., C.M., C.H.G., A.J.W.); and Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom (M.B.S., K.T.M.)
| | - Saptarshi Mukherjee
- From the Institute of Molecular and Experimental Medicine, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom (M.L.B., N.L.T., S.M., C.M., C.H.G., A.J.W.); and Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom (M.B.S., K.T.M.)
| | - Chloe Maxwell
- From the Institute of Molecular and Experimental Medicine, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom (M.L.B., N.L.T., S.M., C.M., C.H.G., A.J.W.); and Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom (M.B.S., K.T.M.)
| | - Kenneth T MacLeod
- From the Institute of Molecular and Experimental Medicine, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom (M.L.B., N.L.T., S.M., C.M., C.H.G., A.J.W.); and Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom (M.B.S., K.T.M.)
| | - Christopher H George
- From the Institute of Molecular and Experimental Medicine, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom (M.L.B., N.L.T., S.M., C.M., C.H.G., A.J.W.); and Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom (M.B.S., K.T.M.)
| | - Alan J Williams
- From the Institute of Molecular and Experimental Medicine, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom (M.L.B., N.L.T., S.M., C.M., C.H.G., A.J.W.); and Myocardial Function Section, National Heart and Lung Institute, Imperial College London, London, United Kingdom (M.B.S., K.T.M.).
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Lagarto J, Dyer BT, Talbot C, Sikkel MB, Peters NS, French PMW, Lyon AR, Dunsby C. Application of time-resolved autofluorescence to label-free in vivo optical mapping of changes in tissue matrix and metabolism associated with myocardial infarction and heart failure. Biomed Opt Express 2015; 6:324-46. [PMID: 25780727 PMCID: PMC4354591 DOI: 10.1364/boe.6.000324] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/17/2014] [Accepted: 10/21/2014] [Indexed: 05/03/2023]
Abstract
We investigate the potential of an instrument combining time-resolved spectrofluorometry and diffuse reflectance spectroscopy to measure structural and metabolic changes in cardiac tissue in vivo in a 16 week post-myocardial infarction heart failure model in rats. In the scar region, we observed changes in the fluorescence signal that can be explained by increased collagen content, which is in good agreement with histology. In areas remote from the scar tissue, we measured changes in the fluorescence signal (p < 0.001) that cannot be explained by differences in collagen content and we attribute this to altered metabolism within the myocardium. A linear discriminant analysis algorithm was applied to the measurements to predict the tissue disease state. When we combine all measurements, our results reveal high diagnostic accuracy in the infarcted area (100%) and border zone (94.44%) as well as in remote regions from the scar (> 77%). Overall, our results demonstrate the potential of our instrument to characterize structural and metabolic changes in a failing heart in vivo without using exogenous labels.
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Affiliation(s)
- João Lagarto
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ
UK
- Authors contributed equally to this work
| | - Benjamin T. Dyer
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN
UK
- Authors contributed equally to this work
| | - Clifford Talbot
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ
UK
| | - Markus B. Sikkel
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN
UK
| | - Nicholas S. Peters
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN
UK
| | - Paul M. W. French
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN
UK
| | - Alexander R. Lyon
- National Heart and Lung Institute, Imperial College London, Du Cane Road, London, W12 0NN
UK
- Authors contributed equally to this work
| | - Chris Dunsby
- Photonics Group, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ
UK
- Authors contributed equally to this work
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Chahine MN, Mioulane M, Sikkel MB, O'Gara P, Dos Remedios CG, Pierce GN, Lyon AR, Földes G, Harding SE. Nuclear pore rearrangements and nuclear trafficking in cardiomyocytes from rat and human failing hearts. Cardiovasc Res 2014; 105:31-43. [PMID: 25341891 PMCID: PMC4277256 DOI: 10.1093/cvr/cvu218] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Aims During cardiac hypertrophy, cardiomyocytes (CMs) increase in the size and expression of cytoskeletal proteins while reactivating a foetal gene programme. The process is proposed to be dependent on increased nuclear export and, since nuclear pore trafficking has limited capacity, a linked decrease in import. Our objective was to investigate the role of nuclear import and export in control of hypertrophy in rat and human heart failure (HF). Methods and results In myocardial tissue and isolated CMs from patients with dilated cardiomyopathy, nuclear size was increased; Nucleoporin p62, cytoplasmic RanBP1, and nuclear translocation of importins (α and β) were decreased while Exportin-1 was increased. CM from a rat HF model 16 weeks after myocardial infarction (MI) reproduced these nuclear changes. Nuclear import, determined by the rate of uptake of nuclear localization sequence (NLS)-tagged fluorescent substrate, was also decreased and this change was observed from 4 weeks after MI, before HF has developed. Treatment of isolated rat CMs with phenylephrine (PE) for 48 h produced similar cell and nuclear size increases, nuclear import and export protein rearrangement, and NLS substrate uptake decrease through p38 MAPK and HDAC-dependent pathways. The change in NLS substrate uptake occurred within 15 min of PE exposure. Inhibition of nuclear export with leptomycin B reversed established nuclear changes in PE-treated rat CMs and decreased NLS substrate uptake and cell/nuclear size in human CMs. Conclusions Nuclear transport changes related to increased export and decreased import are an early event in hypertrophic development. Hypertrophy can be prevented, or even reversed, by targeting import/export, which may open new therapeutic opportunities.
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Affiliation(s)
| | | | | | | | | | - Grant N Pierce
- Institute of Cardiovascular Sciences, St Boniface General Hospital Research Centre, University of Manitoba, Winnipeg, MB, Canada
| | - Alexander R Lyon
- NHLI, Imperial College, London, UK NIHR Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
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Land S, Niederer SA, Louch WE, Røe ÅT, Aronsen JM, Stuckey DJ, Sikkel MB, Tranter MH, Lyon AR, Harding SE, Smith NP. Computational modeling of Takotsubo cardiomyopathy: effect of spatially varying β-adrenergic stimulation in the rat left ventricle. Am J Physiol Heart Circ Physiol 2014; 307:H1487-96. [PMID: 25239804 PMCID: PMC4233305 DOI: 10.1152/ajpheart.00443.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
In Takotsubo cardiomyopathy, the left ventricle shows apical ballooning combined with basal hypercontractility. Both clinical observations in humans and recent experimental work on isolated rat ventricular myocytes suggest the dominant mechanisms of this syndrome are related to acute catecholamine overload. However, relating observed differences in single cells to the capacity of such alterations to result in the extreme changes in ventricular shape seen in Takotsubo syndrome is difficult. By using a computational model of the rat left ventricle, we investigate which mechanisms can give rise to the typical shape of the ventricle observed in this syndrome. Three potential dominant mechanisms related to effects of β-adrenergic stimulation were considered: apical-basal variation of calcium transients due to differences in L-type and sarco(endo)plasmic reticulum Ca2+-ATPase activation, apical-basal variation of calcium sensitivity due to differences in troponin I phosphorylation, and apical-basal variation in maximal active tension due to, e.g., the negative inotropic effects of p38 MAPK. Furthermore, we investigated the interaction of these spatial variations in the presence of a failing Frank-Starling mechanism. We conclude that a large portion of the apex needs to be affected by severe changes in calcium regulation or contractile function to result in apical ballooning, and smooth linear variation from apex to base is unlikely to result in the typical ventricular shape observed in this syndrome. A failing Frank-Starling mechanism significantly increases apical ballooning at end systole and may be an important additional factor underpinning Takotsubo syndrome.
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Affiliation(s)
- Sander Land
- Department of Biomedical Engineering, King's College London, London, United Kingdom
| | - Steven A Niederer
- Department of Biomedical Engineering, King's College London, London, United Kingdom
| | - William E Louch
- Institute for Experimental Medical Research, Oslo University Hospital Ullevål, Oslo, Norway; KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Åsmund T Røe
- Institute for Experimental Medical Research, Oslo University Hospital Ullevål, Oslo, Norway; KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Jan Magnus Aronsen
- Institute for Experimental Medical Research, Oslo University Hospital Ullevål, Oslo, Norway; KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, Oslo, Norway
| | - Daniel J Stuckey
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Markus B Sikkel
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Matthew H Tranter
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Alexander R Lyon
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Insitute of Health Research Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom; and
| | - Sian E Harding
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; National Insitute of Health Research Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, United Kingdom; and
| | - Nicolas P Smith
- Department of Biomedical Engineering, King's College London, London, United Kingdom; Faculty of Engineering, University of Auckland, Auckland, New Zealand
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Mills AM, Sikkel MB, Kumarswamy R, Macleod KT, Lyon AR, Thum T, Harding SE. P393miR-1: a link between SERCA2a and the Beta-Adrenoceptor in the failing heart? Cardiovasc Res 2014. [DOI: 10.1093/cvr/cvu091.75] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sikkel MB, Hayward C, MacLeod KT, Harding SE, Lyon AR. SERCA2a gene therapy in heart failure: an anti-arrhythmic positive inotrope. Br J Pharmacol 2014; 171:38-54. [PMID: 24138023 PMCID: PMC3874695 DOI: 10.1111/bph.12472] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 09/16/2013] [Accepted: 09/24/2013] [Indexed: 01/14/2023] Open
Abstract
Therapeutic options that directly enhance cardiomyocyte contractility in chronic heart failure (HF) therapy are currently limited and do not improve prognosis. In fact, most positive inotropic agents, such as β-adrenoreceptor agonists and PDE inhibitors, which have been assessed in HF patients, cause increased mortality as a result of arrhythmia and sudden cardiac death. Cardiac sarcoplasmic reticulum Ca(2)(+) -ATPase2a (SERCA2a) is a key protein involved in sequestration of Ca(2)(+) into the sarcoplasmic reticulum (SR) during diastole. There is a reduction of SERCA2a protein level and function in HF, which has been successfully targeted via viral transfection of the SERCA2a gene into cardiac tissue in vivo. This has enhanced cardiac contractility and reduced mortality in several preclinical models of HF. Theoretical concerns have been raised regarding the possibility of arrhythmogenic adverse effects of SERCA2a gene therapy due to enhanced SR Ca(2)(+) load and induction of SR Ca(2)(+) leak as a result. Contrary to these concerns, SERCA2a gene therapy in a wide variety of preclinical models, including acute ischaemia/reperfusion, chronic pressure overload and chronic myocardial infarction, has resulted in a reduction in ventricular arrhythmias. The potential mechanisms for this unexpected beneficial effect, as well as mechanisms of enhancement of cardiac contractile function, are reviewed in this article.
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Affiliation(s)
- Markus B Sikkel
- Myocardial Function Section, National Heart and Lung Institute, Imperial CollegeLondon, UK
| | - Carl Hayward
- Myocardial Function Section, National Heart and Lung Institute, Imperial CollegeLondon, UK
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton HospitalLondon, UK
| | - Kenneth T MacLeod
- Myocardial Function Section, National Heart and Lung Institute, Imperial CollegeLondon, UK
| | - Sian E Harding
- Myocardial Function Section, National Heart and Lung Institute, Imperial CollegeLondon, UK
| | - Alexander R Lyon
- Myocardial Function Section, National Heart and Lung Institute, Imperial CollegeLondon, UK
- NIHR Cardiovascular Biomedical Research Unit, Royal Brompton HospitalLondon, UK
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Wright PT, Nikolaev VO, O'Hara T, Diakonov I, Bhargava A, Tokar S, Schobesberger S, Shevchuk AI, Sikkel MB, Wilkinson R, Trayanova NA, Lyon AR, Harding SE, Gorelik J. Caveolin-3 regulates compartmentation of cardiomyocyte beta2-adrenergic receptor-mediated cAMP signaling. J Mol Cell Cardiol 2013; 67:38-48. [PMID: 24345421 DOI: 10.1016/j.yjmcc.2013.12.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 11/28/2013] [Accepted: 12/06/2013] [Indexed: 12/20/2022]
Abstract
The purpose of this study was to investigate whether caveolin-3 (Cav3) regulates localization of β2-adrenergic receptor (β2AR) and its cAMP signaling in healthy or failing cardiomyocytes. We co-expressed wildtype Cav3 or its dominant-negative mutant (Cav3DN) together with the Förster resonance energy transfer (FRET)-based cAMP sensor Epac2-camps in adult rat ventricular myocytes (ARVMs). FRET and scanning ion conductance microscopy were used to locally stimulate β2AR and to measure cytosolic cAMP. Cav3 overexpression increased the number of caveolae and decreased the magnitude of β2AR-cAMP signal. Conversely, Cav3DN expression resulted in an increased β2AR-cAMP response without altering the whole-cell L-type calcium current. Following local stimulation of Cav3DN-expressing ARVMs, β2AR response could only be generated in T-tubules. However, the normally compartmentalized β2AR-cAMP signal became diffuse, similar to the situation observed in heart failure. Finally, overexpression of Cav3 in failing myocytes led to partial β2AR redistribution back into the T-tubules. In conclusion, Cav3 plays a crucial role for the localization of β2AR and compartmentation of β2AR-cAMP signaling to the T-tubules of healthy ARVMs, and overexpression of Cav3 in failing myocytes can partially restore the disrupted localization of these receptors.
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Affiliation(s)
- Peter T Wright
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK
| | - Viacheslav O Nikolaev
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK; Emmy Noether Group of the DFG, Department of Cardiology and Pneumology, Heart Research Center Göttingen, Georg August University, Göttingen, Germany
| | - Thomas O'Hara
- Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Ivan Diakonov
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK
| | - Anamika Bhargava
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK
| | - Sergiy Tokar
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK
| | - Sophie Schobesberger
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK
| | | | - Markus B Sikkel
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK
| | - Ross Wilkinson
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK
| | - Natalia A Trayanova
- Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Alexander R Lyon
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK; Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London, UK
| | - Sian E Harding
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK
| | - Julia Gorelik
- Department of Cardiovascular Sciences, National Heart and Lung Institute, Imperial College, London, UK.
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Abstract
Takotsubo cardiomyopathy (TTC) is an acute heart failure syndrome classically characterized by hypocontractile apical and midventricular regions of the left ventricle, with a compensatory hypercontractile base. Available data support the hypothesis that TTC and atypical TTC-like disorders are primarily induced by catecholaminergic overstimulation, with epinephrine playing a crucial role. Knowledge from the available preclinical models should be used to guide the development of potential clinical trials in the most severe cases, where rates of acute morbidity and mortality are highest, and also to prevent recurrence in susceptible individuals.
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Affiliation(s)
- Matthew H Tranter
- Myocardial Function Section, National Heart and Lung Institute, Imperial College London, Du Cane Road, London W12 0NN, UK
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Sikkel MB, MacLeod KT, Gordon F. Letter by Sikkel et al regarding article, "Late sodium current inhibition reverses electromechanical dysfunction in human hypertrophic cardiomyopathy". Circulation 2013; 128:e156. [PMID: 24002720 DOI: 10.1161/circulationaha.113.003070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Abstract
Systems biology describes a holistic and integrative approach to understand physiology and pathology. The “omic” disciplines include genomics, transcriptomics, proteomics, and metabolic profiling (metabonomics and metabolomics). By adopting a stance, which is opposing (yet complimentary) to conventional research techniques, systems biology offers an overview by assessing the “net” biological effect imposed by a disease or nondisease state. There are a number of different organizational levels to be understood, from DNA to protein, metabolites, cells, organs and organisms, even beyond this to an organism’s context. Systems biology relies on the existence of “nodes” and “edges.” Nodes are the constituent part of the system being studied (eg, proteins in the proteome), while the edges are the way these constituents interact. In future, it will be increasingly important to collaborate, collating data from multiple studies to improve data sets, making them freely available and undertaking integrative analyses.
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Affiliation(s)
- Joseph Shalhoub
- Department of Surgery & Cancer, Academic Section of Vascular Surgery, Imperial College London, United Kingdom
| | - Markus B. Sikkel
- Myocardial Function Section, National Heart & Lung Institute, Imperial College London, United Kingdom
| | - Kerry J. Davies
- Department of Surgery & Cancer, Academic Section of Vascular Surgery, Imperial College London, United Kingdom
| | - Panagiotis A. Vorkas
- Department of Surgery & Cancer, Computational & Systems Medicine, Imperial College London, United Kingdom
| | - Elizabeth J. Want
- Department of Surgery & Cancer, Computational & Systems Medicine, Imperial College London, United Kingdom
| | - Alun H. Davies
- Department of Surgery & Cancer, Academic Section of Vascular Surgery, Imperial College London, United Kingdom
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Toepfer C, Caorsi V, Kampourakis T, Sikkel MB, West TG, Leung MC, Al-Saud SA, MacLeod KT, Lyon AR, Marston SB, Sellers JR, Ferenczi MA. Myosin regulatory light chain (RLC) phosphorylation change as a modulator of cardiac muscle contraction in disease. J Biol Chem 2013; 288:13446-54. [PMID: 23530050 PMCID: PMC3650382 DOI: 10.1074/jbc.m113.455444] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/21/2013] [Indexed: 01/26/2023] Open
Abstract
Understanding how cardiac myosin regulatory light chain (RLC) phosphorylation alters cardiac muscle mechanics is important because it is often altered in cardiac disease. The effect this protein phosphorylation has on muscle mechanics during a physiological range of shortening velocities, during which the heart generates power and performs work, has not been addressed. We have expressed and phosphorylated recombinant Rattus norvegicus left ventricular RLC. In vitro we have phosphorylated these recombinant species with cardiac myosin light chain kinase and zipper-interacting protein kinase. We compare rat permeabilized cardiac trabeculae, which have undergone exchange with differently phosphorylated RLC species. We were able to enrich trabecular RLC phosphorylation by 40% compared with controls and, in a separate series, lower RLC phosphorylation to 60% of control values. Compared with the trabeculae with a low level of RLC phosphorylation, RLC phosphorylation enrichment increased isometric force by more than 3-fold and peak power output by more than 7-fold and approximately doubled both maximum shortening speed and the shortening velocity that generated peak power. We augmented these measurements by observing increased RLC phosphorylation of human and rat HF samples from endocardial left ventricular homogenate. These results demonstrate the importance of increased RLC phosphorylation in the up-regulation of myocardial performance and suggest that reduced RLC phosphorylation is a key aspect of impaired contractile function in the diseased myocardium.
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Affiliation(s)
- Christopher Toepfer
- From the Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
- the Laboratory of Molecular Physiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Valentina Caorsi
- From the Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
| | - Thomas Kampourakis
- the Randall Division of Cell and Molecular Biophysics, Guy's Campus, King's College London, London SE1 1UL, United Kingdom
| | - Markus B. Sikkel
- the National Heart and Lung Institute, 4th Floor, Imperial Center for Translational and Experimental Medicine, Hammersmith Campus, Du Cane Road, London W12 0NN, United Kingdom
| | - Timothy G. West
- the Structure and Motion Laboratory, Royal Veterinary College London, North Mymms AL9 7TA, United Kingdom
| | - Man-Ching Leung
- the National Heart and Lung Institute, 4th Floor, Imperial Center for Translational and Experimental Medicine, Hammersmith Campus, Du Cane Road, London W12 0NN, United Kingdom
| | - Sara A. Al-Saud
- From the Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
| | - Kenneth T. MacLeod
- the National Heart and Lung Institute, 4th Floor, Imperial Center for Translational and Experimental Medicine, Hammersmith Campus, Du Cane Road, London W12 0NN, United Kingdom
| | - Alexander R. Lyon
- the National Heart and Lung Institute, 4th Floor, Imperial Center for Translational and Experimental Medicine, Hammersmith Campus, Du Cane Road, London W12 0NN, United Kingdom
- the Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, London SW3 6MP, United Kingdom
| | - Steven B. Marston
- the National Heart and Lung Institute, 4th Floor, Imperial Center for Translational and Experimental Medicine, Hammersmith Campus, Du Cane Road, London W12 0NN, United Kingdom
| | - James R. Sellers
- the Laboratory of Molecular Physiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Michael A. Ferenczi
- From the Molecular Medicine Section, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
- the Lee Kong Chian School of Medicine, Nanyang Technological University, 637553 Singapore
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Sikkel MB, Collins TP, Rowlands C, Shah M, O'Gara P, Williams AJ, Harding SE, Lyon AR, MacLeod KT. Triple mode of action of flecainide in catecholaminergic polymorphic ventricular tachycardia: reply. Cardiovasc Res 2013; 98:327-8. [PMID: 23536607 DOI: 10.1093/cvr/cvt068] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Caorsi V, Toepfer C, Sikkel MB, Lyon AR, MacLeod K, Ferenczi MA. Non-linear optical microscopy sheds light on cardiovascular disease. PLoS One 2013; 8:e56136. [PMID: 23409139 PMCID: PMC3567079 DOI: 10.1371/journal.pone.0056136] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 01/05/2013] [Indexed: 11/29/2022] Open
Abstract
Many cardiac diseases have been associated with increased fibrosis and changes in the organization of fibrillar collagen. The degree of fibrosis is routinely analyzed with invasive histological and immunohistochemical methods, giving a limited and qualitative understanding of the tissue's morphological adaptation to disease. Our aim is to quantitatively evaluate the increase in fibrosis by three-dimensional imaging of the collagen network in the myocardium using the non-linear optical microscopy techniques Two-Photon Excitation microscopy (TPE) and Second Harmonic signal Generation (SHG). No sample staining is needed because numerous endogenous fluorophores are excited by a two-photon mechanism and highly non-centrosymmetric structures such as collagen generate strong second harmonic signals. We propose for the first time a 3D quantitative analysis to carefully evaluate the increased fibrosis in tissue from a rat model of heart failure post myocardial infarction. We show how to measure changes in fibrosis from the backward SHG (BSHG) alone, as only backward-propagating SHG is accessible for true in vivo applications. A 5-fold increase in collagen I fibrosis is detected in the remote surviving myocardium measured 20 weeks after infarction. The spatial distribution is also shown to change markedly, providing insight into the morphology of disease progression.
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Affiliation(s)
- Valentina Caorsi
- Molecular Medicine, National Heart and Lung Institute, Imperial College London, London, United Kingdom.
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Sikkel MB, Collins TP, Rowlands C, Shah M, O'Gara P, Williams AJ, Harding SE, Lyon AR, MacLeod KT. Flecainide reduces Ca(2+) spark and wave frequency via inhibition of the sarcolemmal sodium current. Cardiovasc Res 2013; 98:286-96. [PMID: 23334259 PMCID: PMC3714924 DOI: 10.1093/cvr/cvt012] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Aims Ca2+ waves are thought to be important in the aetiology of
ventricular tachyarrhythmias. There have been conflicting results regarding
whether flecainide reduces Ca2+ waves in isolated
cardiomyocytes. We sought to confirm whether flecainide inhibits waves in
the intact cardiomyocyte and to elucidate the mechanism. Methods and results We imaged spontaneous sarcoplasmic reticulum (SR) Ca2+
release events in healthy adult rat cardiomyocytes. Variation in stimulation
frequency was used to produce Ca2+ sparks or waves. Spark
frequency, wave frequency, and wave velocity were reduced by flecainide in
the absence of a reduction of SR Ca2+ content. Inhibition
of INa via alternative pharmacological agents
(tetrodotoxin, propafenone, or lidocaine) produced similar changes. To
assess the contribution of INa to spark and wave
production, voltage clamping was used to activate contraction from holding
potentials of −80 or −40 mV. This confirmed that reducing
Na+ influx during myocyte stimulation is sufficient to
reduce waves and that flecainide only causes Ca2+ wave
reduction when INa is active. It was found that
Na+/Ca2+-exchanger (NCX)-mediated
Ca2+ efflux was significantly enhanced by flecainide
and that the effects of flecainide on wave frequency could be reversed by
reducing [Na+]o, suggesting an important
downstream role for NCX function. Conclusion Flecainide reduces spark and wave frequency in the intact rat cardiomyocyte
at therapeutically relevant concentrations but the mechanism involves
INa reduction rather than direct ryanodine
receptor (RyR2) inhibition. Reduced INa results
in increased Ca2+ efflux via NCX across the sarcolemma,
reducing Ca2+ concentration in the vicinity of the
RyR2.
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Affiliation(s)
- Markus B Sikkel
- Myocardial Function Section, National Heart and Lung Institute, Fourth Floor, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London W12 0NN, UK.
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Toepfer C, Caorsi V, Kampourakis T, Sikkel MB, West T, Leung JC, Al-Saud SA, Macleod K, Lyon AR, Marston SB, Sellers J, Ferenczi MA. Myosin Regulatory Light Chain (RLC) Phosphorylation Change as a Modulator of Cardiac Muscle Contraction in Disease. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.1720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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