1
|
van der Stuijt W, Pepplinkhuizen S, de Veld JA, Quast ABE, van Halm VP, Bijsterveld NR, Olde Nordkamp LRA, Wilde AAM, Smeding L, Knops RE. Defibrillation threshold in elective subcutaneous implantable defibrillator generator replacements: Time to reduce the size of the pulse generator? Int J Cardiol 2024; 398:131639. [PMID: 38065323 DOI: 10.1016/j.ijcard.2023.131639] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 11/11/2023] [Accepted: 12/03/2023] [Indexed: 01/23/2024]
Abstract
INTRODUCTION The first step-down defibrillation studies in the subcutaneous implantable cardioverter-defibrillator (S-ICD) described a defibrillation threshold (DFT) of 32.5 ± 17.0 J and 36.6 ± 19.8 J. Therefore, the default shock output of the S-ICD was set at 80 J. In de novo implants, the DFT is lower in optimally positioned S-ICDs. However, a retrospective analysis raised concerns about a high DFT in S-ICD replacements, possibly related to fibrosis. OBJECTIVE We aimed to find the DFT in patients undergoing S-ICD generator replacement. METHODS This prospective study enrolled patients who underwent S-ICD generator replacement with subsequent defibrillation testing. A pre-specified defibrillation testing protocol was used to determine the DFT, defined as the lowest shock output that effectively terminated the induced ventricular arrhythmia. RESULTS A total of 45 patients were enrolled, 6.0 ± 2.1 years after initial implant. Mean DFT during replacement in the total cohort was 27.4 ± 14.3 J. In patients with a body mass index (BMI) 18.5-25 kg/m2 (N = 22, BMI 22.5 ± 1.6), median DFT was 20 J (IQR 17.5-30). In 18/22 patients, the DFT was ≤30 J and 5/22 patients were successfully defibrillated at 10 J. One patient with hypertrophic cardiomyopathy had a DFT of 65 J. In patients with a BMI >25 kg/m2 (N = 23, BMI 29.5 ± 4.2), median DFT was 30 J (IQR 20-40). In 15/23 patients, the DFT was ≤30 J and 4/23 patients had a successful defibrillation test at 10 J. CONCLUSIONS This study eases concerns about a high DFT after S-ICD generator replacement. The majority of patients had a DFT ≤30 J, regardless of BMI, suggesting that the shock output of the S-ICD could be safely reduced.
Collapse
Affiliation(s)
- W van der Stuijt
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands.
| | - S Pepplinkhuizen
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| | - J A de Veld
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| | - A B E Quast
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| | - V P van Halm
- Amsterdam UMC, Location VUmc, Department of Cardiology, Boelelaan 1117, 1081 HV Amsterdam, the Netherlands
| | - N R Bijsterveld
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| | - L R A Olde Nordkamp
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| | - A A M Wilde
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| | - L Smeding
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| | - R E Knops
- Amsterdam UMC Location University of Amsterdam, Department of Cardiology, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Meibergdreef 9, 1105AZ Amsterdam, the Netherlands
| |
Collapse
|
2
|
Szyller J, Antoniak R, Wadowska K, Bil-Lula I, Hrymniak B, Banasiak W, Jagielski D. Redox imbalance in patients with heart failure and ICD/CRT-D intervention. Can it be an underappreciated and overlooked arrhythmogenic factor? A first preliminary clinical study. Front Physiol 2023; 14:1289587. [PMID: 38028798 PMCID: PMC10663344 DOI: 10.3389/fphys.2023.1289587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction: Redox imbalance and oxidative stress are involved in the pathogenesis of arrhythmias. They also play a significant role in pathogenesis of heart failure (HF). In patients with HFand implanted cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D), the direct current shocks may be responsible for additional redox disturbances and additionally increase arrhythmia risk. However, the precise role of oxidative stress in potentially fatal arrhythmias and shock induction remains unclear. Methods: 36 patients with diagnosed HF and implanted ICD/CRT-D were included in this study. Patients were qualified to the study group in case of registered ventricular arrhythmia and adequate ICD/CRT-D intervention. The control group consisted of patients without arrhythmia with elective replacement indicator (ERI) status. Activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH) in erythrocyte (RBC), SOD, GPx activity and reactive oxygen/nitrogen species (ROS/RNS) concentration in plasma were determined. The values were correlated with glucose, TSH, uric acid, Mg and ion concentrations. Results: In the perishock period, we found a significant decrease in RBC and extracellular (EC) SOD and RBC CAT activity (p = 0.0110, p = 0.0055 and p = 0.0002, respectively). EC GPx activity was also lower (p = 0.0313). In all patients, a decrease in the concentration of all forms of glutathione was observed compared to the ERI group. Important association between ROS/RNS and GSH, Mg, TSH and uric acid was shown. A relationship between the activity of GSH and antioxidant enzymes was found. Furthermore, an association between oxidative stress and ionic imbalance has also been demonstrated. The patients had an unchanged de Haan antioxidant ratio and glutathione redox potential. Conclusion: Here we show significant redox disturbances in patients with HF and ICD/CRT-D interventions. Oxidative stress may be an additional risk factor for the development of arrhythmia in patients with HF. The detailed role of oxidative stress in ventricular arrhythmias requires further research already undertaken by our team.
Collapse
Affiliation(s)
- Jakub Szyller
- Division of Clinical Chemistry and Laboratory Hematology, Department of Medical Laboratory Diagnostics, Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| | - Radosław Antoniak
- Department of Cardiology, Centre for Heart Diseases, 4th Military Hospital, Wroclaw, Poland
| | - Katarzyna Wadowska
- Division of Clinical Chemistry and Laboratory Hematology, Department of Medical Laboratory Diagnostics, Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| | - Iwona Bil-Lula
- Division of Clinical Chemistry and Laboratory Hematology, Department of Medical Laboratory Diagnostics, Faculty of Pharmacy, Wroclaw Medical University, Wroclaw, Poland
| | - Bruno Hrymniak
- Department of Cardiology, Centre for Heart Diseases, 4th Military Hospital, Wroclaw, Poland
| | - Waldemar Banasiak
- Department of Cardiology, Centre for Heart Diseases, 4th Military Hospital, Wroclaw, Poland
- Faculty of Medicine, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Dariusz Jagielski
- Department of Cardiology, Centre for Heart Diseases, 4th Military Hospital, Wroclaw, Poland
- Faculty of Medicine, Wroclaw University of Science and Technology, Wroclaw, Poland
| |
Collapse
|
3
|
Milan HFM, Almazloum AA, Bassani RA, Bassani JWM. Membrane polarization at the excitation threshold induced by external electric fields in cardiomyocytes of rats at different developmental stages. Med Biol Eng Comput 2023; 61:2637-2647. [PMID: 37405671 DOI: 10.1007/s11517-023-02868-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 06/07/2023] [Indexed: 07/06/2023]
Abstract
External electric fields (E), used for cardiac pacing and defibrillation/cardioversion, induce a spatially variable change in cardiomyocyte transmembrane potential (ΔVm) that depends on cell geometry and E orientation. This study investigates E-induced ΔVm in cardiomyocytes from rats at different ages, which show marked size/geometry variation. Using a tridimensional numerical electromagnetic model recently proposed (NM3D), it was possible: (a) to evaluate the suitability of the simpler, prolate spheroid analytical model (PSAM) to calculate amplitude and location of ΔVm maximum (ΔVmax) for E = 1 V.cm-1; and (b) to estimate the ΔVmax required for excitation (ΔVT) from experimentally determined threshold E values (ET). Ventricular myocytes were isolated from neonatal, weaning, adult, and aging Wistar rats. NM3D was constructed as the extruded 2D microscopy cell image, while measured minor and major cell dimensions were used for PSAM. Acceptable ΔVm estimates can be obtained with PSAM from paralelepidal cells for small θ. ET, but not ΔVT, was higher for neonate cells. ΔVT was significantly greater in the cell from older animals, which indicate lower responsiveness to E associated with aging, rather than with altered cell geometry/dimensions. ΔVT might be used as a non-invasive indicator of cell excitability as it is little affected by cell geometry/size.
Collapse
Affiliation(s)
- Hugo F M Milan
- Department of Electronics and Biomedical Engineering, School of Electrical and Computer Engineering, University of Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, Av. Albert Einstein 400, Campinas, SP, 13083-852, Brazil.
| | - Ahmad A Almazloum
- Department of Electronics and Biomedical Engineering, School of Electrical and Computer Engineering, University of Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, Av. Albert Einstein 400, Campinas, SP, 13083-852, Brazil
| | - Rosana A Bassani
- Department of Electronics and Biomedical Engineering, School of Electrical and Computer Engineering, University of Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, Av. Albert Einstein 400, Campinas, SP, 13083-852, Brazil
- LabNECC, Center for Biomedical Engineering (CEB), University of Campinas (UNICAMP), R. Alexander Fleming 163, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-881, Brazil
| | - José W M Bassani
- Department of Electronics and Biomedical Engineering, School of Electrical and Computer Engineering, University of Campinas (UNICAMP), Cidade Universitária Zeferino Vaz, Av. Albert Einstein 400, Campinas, SP, 13083-852, Brazil
- LabNECC, Center for Biomedical Engineering (CEB), University of Campinas (UNICAMP), R. Alexander Fleming 163, Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-881, Brazil
| |
Collapse
|
4
|
Perel N, Tovia-Brodie O, Rav Acha M, Accinelli S, Levy EE, Glikson M, Michowitz Y. Lack of magnet use during chest compressions leads to multiple inappropriate shocks by a subcutaneous implantable cardioverter-defibrillator. HeartRhythm Case Rep 2022; 8:815-819. [PMID: 36620368 PMCID: PMC9811013 DOI: 10.1016/j.hrcr.2022.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Affiliation(s)
- Nimrod Perel
- Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Faculty of Medicine Hebrew University, Jerusalem, Israel
| | - Oholi Tovia-Brodie
- Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Faculty of Medicine Hebrew University, Jerusalem, Israel
| | - Moshe Rav Acha
- Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Faculty of Medicine Hebrew University, Jerusalem, Israel
| | | | | | - Michael Glikson
- Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Faculty of Medicine Hebrew University, Jerusalem, Israel
| | - Yoav Michowitz
- Jesselson Integrated Heart Center, Shaare Zedek Medical Center, Faculty of Medicine Hebrew University, Jerusalem, Israel,Address reprint requests and correspondence: Dr Yoav Michowitz, Department of Cardiology, Shaare Zedek Hospital, 12 Shmuel Beit St, Jerusalem 9103102, Israel.
| |
Collapse
|
5
|
Antioxidants in Arrhythmia Treatment—Still a Controversy? A Review of Selected Clinical and Laboratory Research. Antioxidants (Basel) 2022; 11:antiox11061109. [PMID: 35740006 PMCID: PMC9220256 DOI: 10.3390/antiox11061109] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/26/2022] [Accepted: 06/01/2022] [Indexed: 02/04/2023] Open
Abstract
Antioxidants are substances that can prevent damage to cells caused by free radicals. Production of reactive oxygen species and the presence of oxidative stress play an important role in cardiac arrhythmias. Currently used antiarrhythmic drugs have many side effects. The research on animals and humans using antioxidants (such as vitamins C and E, resveratrol and synthetic substances) yields many interesting but inconclusive results. Natural antioxidants, such as vitamins C and E, can reduce the recurrence of atrial fibrillation (AF) after successful electrical cardioversion and protect against AF after cardiac surgery, but do not affect the incidence of atrial arrhythmias in critically ill patients with trauma. Vitamins C and E may also effectively treat ventricular tachycardia, ventricular fibrillation and long QT-related arrhythmias. Another natural antioxidant—resveratrol—may effectively treat AF and ventricular arrhythmias caused by ischaemia–reperfusion injury. It reduces the mortality associated with life-threatening ventricular arrhythmias and can be used to prevent myocardial remodelling. Statins also show antioxidant activity. Their action is related to the reduction of oxidative stress and anti-inflammatory effect. Therefore, statins can reduce the post-operative risk of AF and may be useful in lowering its recurrence rate after successful cardioversion. Promising results also apply to polyphenols, nitric oxide synthase inhibitors and MitoTEMPO. Although few clinical trials have been conducted, the use of antioxidants in treating arrhythmias is an interesting prospect.
Collapse
|
6
|
Elsokkari I, Tsuji Y, Sapp JL, Nattel S. Recent insights into mechanisms and clinical approaches to electrical storm. Can J Cardiol 2021; 38:439-453. [PMID: 34979281 DOI: 10.1016/j.cjca.2021.12.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 12/21/2021] [Accepted: 12/30/2021] [Indexed: 12/14/2022] Open
Abstract
Electrical storm, characterized by repetitive ventricular tachycardia/fibrillation (VT/VF) over a short period, is becoming commoner with widespread use of implantable cardioverter-defibrillator (ICD) therapy. Electrical storm, sometimes called "arrhythmic storm" or "VT-storm", is usually a medical emergency requiring hospitalization and expert management, and significantly affects short- and long-term outcomes. This syndrome typically occurs in patients with underlying structural heart disease (ischemic or non-ischemic cardiomyopathy) or inherited channelopathies. Triggers for electrical storm should be sought but are often unidentifiable. Initial management is dictated by the hemodynamic status, while subsequent management typically involves ICD interrogation and reprogramming to reduce recurrent shocks, identification/management of triggers like electrolyte abnormalities, myocardial ischemia, or decompensated heart failure, and antiarrhythmic-drug therapy or catheter ablation. Sympathetic nervous system activation is central to the initiation and maintenance of arrhythmic storm, so autonomic modulation is a cornerstone of management. Sympathetic inhibition can be achieved with medications (particularly beta-adrenoreceptor blockers), deep sedation, or cardiac sympathetic denervation. More definitive management targets the underlying ventricular arrhythmia substrate to terminate and prevent recurrent arrhythmia. Arrhythmia targeting can be achieved with antiarrhythmic medications, catheter ablation or more novel therapies such as stereotactic radiation therapy that targets the arrhythmic substrate. Mechanistic studies point to adrenergic activation and other direct consequences of ICD-shocks in promoting further arrhythmogenesis and hypocontractility. Here, we review the pathophysiologic mechanisms, clinical features, prognosis, and therapeutic options for electrical storm. We also outline a clinical approach to this challenging and complex condition, along with its mechanistic basis.
Collapse
Affiliation(s)
- Ihab Elsokkari
- University of Sydney, Nepean Blue Mountains local health district, Australia
| | - Yukiomi Tsuji
- Department of Physiology of Visceral Function, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - John L Sapp
- Dalhousie University, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada.
| | - Stanley Nattel
- Departments of Medicine and Research Center, Montreal Heart Institute and Université de Montréal and Pharmacology and Therapeutics McGill University, Montreal, Quebec, Canada; Institute of Pharmacology, West German Heart and Vascular Center, University of Duisburg-Essen, Essen, Germany; IHU LIYRC Institute, Bordeaux, France.
| |
Collapse
|