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Waddingham PH, Mangual JO, Orini M, Badie N, Muthumala A, Sporton S, McSpadden LC, Lambiase PD, Chow AWC. Electrocardiographic imaging demonstrates electrical synchrony improvement by dynamic atrioventricular delays in patients with left bundle branch block and preserved atrioventricular conduction. Europace 2023; 25:536-545. [PMID: 36480445 PMCID: PMC9935053 DOI: 10.1093/europace/euac224] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 11/01/2022] [Indexed: 12/13/2022] Open
Abstract
AIMS Cardiac resynchronization therapy programmed to dynamically fuse pacing with intrinsic conduction using atrioventricular (AV) timing algorithms (e.g. SyncAV) has shown promise; however, mechanistic data are lacking. This study assessed the impact of SyncAV on electrical dyssynchrony across various pacing modalities using non-invasive epicardial electrocardiographic imaging (ECGi). METHODS AND RESULTS Twenty-five patients with left bundle-branch block (median QRS duration (QRSd) 162.7 ms) and intact AV conduction (PR interval 174.0 ms) were prospectively enrolled. ECGi was performed acutely during biventricular pacing with fixed nominal AV delays (BiV) and using SyncAV (optimized for the narrowest QRSd) during: BiV + SyncAV, LV-only single-site (LVSS + SyncAV), MultiPoint pacing (MPP + SyncAV), and LV-only MPP (LVMPP + SyncAV). Dyssynchrony was quantified via ECGi (LV activation time, LVAT; RV activation time, RVAT; LV electrical dispersion index, LVEDi; ventricular electrical uncoupling index, VEU; and biventricular total activation time, VVtat). Intrinsic conduction LVAT (124 ms) was significantly reduced by BiV pacing (109 ms) (P = 0.001) and further reduced by LVSS + SyncAV (103 ms), BiV + SyncAV (103 ms), LVMPP + SyncAV (95 ms), and MPP + SyncAV (90 ms). Intrinsic RVAT (93 ms), VVtat (130 ms), LVEDi (36 ms), VEU (50 ms), and QRSd (163 ms) were reduced by SyncAV across all pacing modes. More patients exhibited minimal LVAT, VVtat, LVEDi, and QRSd with MPP + SyncAV than any other modality. CONCLUSION Dynamic AV delay programming targeting fusion with intrinsic conduction significantly reduced dyssynchrony, as quantified by ECGi and QRSd for all evaluated pacing modes. MPP + SyncAV achieved the greatest synchrony overall but not for all patients, highlighting the value of pacing mode individualization during fusion optimization.
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Affiliation(s)
- Peter H Waddingham
- Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London EC1A 7BE, United Kingdom.,William Harvey Research Institute, Charterhouse Square, Queen Mary University of London, London EC1M 6BQ, UK
| | | | - Michele Orini
- Institute of Cardiovascular Science, University College London, London, UK
| | | | - Amal Muthumala
- Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London EC1A 7BE, United Kingdom
| | - Simon Sporton
- Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London EC1A 7BE, United Kingdom
| | | | - Pier D Lambiase
- Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London EC1A 7BE, United Kingdom.,Institute of Cardiovascular Science, University College London, London, UK
| | - Anthony W C Chow
- Barts Heart Centre, St. Bartholomew's Hospital, West Smithfield, London EC1A 7BE, United Kingdom.,William Harvey Research Institute, Charterhouse Square, Queen Mary University of London, London EC1M 6BQ, UK
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O'Donnell D, Manyam H, Pappone C, Park SJ, Leclercq C, Lunati M, Lercher P, Rordorf R, Landolina M, Badie N, McSpadden LC, Ryu K, Mangual JO, Singh JP, Varma N, Niazi IK. Ventricular activation patterns during intrinsic conduction and right ventricular pacing in cardiac resynchronization therapy patients. Pacing Clin Electrophysiol 2021; 44:1663-1670. [PMID: 34319603 DOI: 10.1111/pace.14329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 07/10/2021] [Accepted: 07/18/2021] [Indexed: 11/28/2022]
Abstract
BACKGROUND Cardiac resynchronization therapy (CRT) involves stimulation of both right ventricle (RV) and left ventricle (LV). LV pacing from the sites of delayed electrical activation improves CRT response. The RV-LV conduction is typically measured in intrinsic rhythm. The differences in RV-LV conduction patterns and timing between intrinsic rhythm and during paced RV activation, these differences are not fully understood. METHODS Enrolled patients were implanted with a de novo CRT device and quadripolar LV lead, with lead implant locations at the implanting physician's discretion. QRS duration and conduction delay between the RV lead and each of the four LV electrodes (D1, M2, M3, and P4) were measured during intrinsic conduction and RV pacing. RESULTS Conduction measurements were collected from 275 patients across 14 international centers (68 ± 13 years of age, 73% male, 45% ischemic, 158 ± 22 ms QRS duration). Mean RV-LV conduction time was shorter during intrinsic conduction versus RV pacing by 59.6 ms (106.5 ± 36.5 versus 166.1 ± 32.1 ms, p < 0.001). The intra-LV activation delay between the latest and earliest activating LV electrode was also shorter during intrinsic conduction versus RV pacing by 6.6 ms (20.6 ± 13.1 vs. 27.2 ± 21.2 ms, p < 0.001). Intrinsic conduction and RV pacing resulted in a different activation order in 72.7% of patients, and the same LV activation order in 27.3%. CONCLUSIONS Differences in RV-LV conduction time, intra-LV conduction time, and activation pattern were observed between intrinsic conduction and RV pacing. These findings highlight the importance of evaluating intrinsic versus paced ventricular activation to guide LV pacing site selection in CRT patients.
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Affiliation(s)
- David O'Donnell
- Cardiology, GenesisCare, Wellington Parade, Melbourne, Australia
| | - Harish Manyam
- Department of Cardiology, Erlanger Hospital University of Tennessee, Chattanooga, Tennessee, USA
| | - Carlo Pappone
- Department of Arrhythmology, I.R.C.C.S. Policlinico San Donato, San Donato Milanese, Italy
| | - Seung-Jung Park
- Samsung Medical Center, Sungkyunkwan School of Medicine, Seoul, Korea
| | | | - Maurizio Lunati
- Cardiac Department, Niguarda Ca' Granda, Granda Hospital, Milan, Italy
| | - Peter Lercher
- Department of Cardiology, Medical University Graz, Graz, Austria
| | - Roberto Rordorf
- Coronay Care Unit, Department of Cardiology, Fondazione Policlinico San Matteo, Pavia, Italy
| | - Maurizio Landolina
- Coronay Care Unit, Department of Cardiology, Fondazione Policlinico San Matteo, Pavia, Italy.,Cardiology Department, Ospedale Maggiore di Crema, Crema, Italy
| | | | | | | | | | - Jagmeet P Singh
- Cardiac Arrhythmia Service, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Niraj Varma
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Imran K Niazi
- Aurora Cardiovascular Services, Aurora Sinai/Aurora St. Luke's Medical Centers, Milwaukee, Wisconsin, USA
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Ciconte G, Vicedomini G, Li W, Mangual JO, McSpadden L, Ryu K, Saviano M, Vitale R, Conti M, Ćalović Ž, Santinelli V, Pappone C. Non-paroxysmal atrial fibrillation mapping: characterization of the electrophysiological substrate using a novel integrated mapping technique. Europace 2020; 21:1193-1202. [PMID: 31056645 DOI: 10.1093/europace/euz123] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 11/11/2018] [Accepted: 04/12/2019] [Indexed: 01/05/2023] Open
Abstract
AIMS Clinical outcomes after radiofrequency catheter ablation (RFCA) remain suboptimal in the treatment of non-paroxysmal atrial fibrillation (AF). Electrophysiological mapping may improve understanding of the underlying mechanisms. To describe the arrhythmia substrate in patients with persistent (Pers) and long-standing persistent (LSPers) AF, undergoing RFCA, using an integrated mechanism mapping technique. METHODS AND RESULTS Patients underwent high-density electroanatomical mapping before and after catheter ablation. Integrated maps characterized electrogram (EGM) cycle length (CL) in regions with repetitive-regular (RR) activations, stable wavefront propagation, fragmentation, and peak-to-peak bipolar voltage. Among 83 patients (72% male, 60 ± 11 years old), RR activations were identified in 376 regions (mean CL 180 ± 31 ms). PersAF patients (n = 43) showed more RR sites per patient (5.3 ± 2.4 vs. 3.7 ± 2.1, P = 0.002) with faster CL (166 ± 29 vs. 190 ± 29 ms; P < 0.001) and smaller surface area of fragmented EGMs (15 ± 14% vs. 27 ± 17%, P < 0.001) compared with LSPersAF. The post-ablation map in 50 patients remaining in AF, documented reduction of the RR activities per patient (1.5 ± 0.7 vs. 3.7 ± 1.4, P < 0.001) and area of fragmentation (22 ± 17% vs. 8 ± 9%, P < 0.001). Atrial fibrillation termination during ablation occurred at RR sites (0.48 ± 0.24 mV; 170.5 ± 20.2 ms CL) in 31/33 patients (94%). At the latest follow-up, arrhythmia freedom was higher among patients receiving ablation >75% of RR sites (Q4 82.6%, Q3 63.1%, Q2 35.1%, and Q1 0%; P < 0.001). CONCLUSION The integrated mapping technique allowed characterization of multiple arrhythmic substrates in non-paroxysmal AF patients. This technique might serve as tool for a substrate-targeted ablation approach.
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Affiliation(s)
- Giuseppe Ciconte
- Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, San Donato Milanese, Milano, Italy
| | - Gabriele Vicedomini
- Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, San Donato Milanese, Milano, Italy
| | - Wenwen Li
- Applied Research, Abbott, Sylmar, CA, USA
| | | | | | | | - Massimo Saviano
- Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, San Donato Milanese, Milano, Italy
| | - Raffaele Vitale
- Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, San Donato Milanese, Milano, Italy
| | - Manuel Conti
- Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, San Donato Milanese, Milano, Italy
| | - Žarko Ćalović
- Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, San Donato Milanese, Milano, Italy
| | - Vincenzo Santinelli
- Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, San Donato Milanese, Milano, Italy
| | - Carlo Pappone
- Department of Arrhythmology, IRCCS Policlinico San Donato, Piazza E. Malan 1, San Donato Milanese, Milano, Italy
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Thibault B, Ritter P, Bode K, Calò L, Mondésert B, Mangual JO, Badie N, McSpadden LC, Pappone C, Varma N. Dynamic programming of atrioventricular delay improves electrical synchrony in a multicenter cardiac resynchronization therapy study. Heart Rhythm 2019; 16:1047-1056. [DOI: 10.1016/j.hrthm.2019.01.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Indexed: 10/27/2022]
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Pappone C, Ciconte G, Vicedomini G, Mangual JO, Li W, Conti M, Giannelli L, Lipartiti F, McSpadden L, Ryu K, Guazzi M, Menicanti L, Santinelli V. Clinical Outcome of Electrophysiologically Guided Ablation for Nonparoxysmal Atrial Fibrillation Using a Novel Real-Time 3-Dimensional Mapping Technique: Results From a Prospective Randomized Trial. Circ Arrhythm Electrophysiol 2019. [PMID: 29535136 DOI: 10.1161/circep.117.005904] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [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] [Indexed: 11/16/2022]
Abstract
BACKGROUND Clinical outcomes after ablation of persistent atrial fibrillation remain suboptimal. Identification of AF drivers using a novel integrated mapping technique may be crucial to ameliorate the clinical outcome. METHODS AND RESULTS Persistent AF patients were prospectively enrolled to undergo high-density electrophysiological mapping to identify repetitive-regular activities (RRas) before modified circumferential pulmonary vein (PV) ablation. They have been randomly assigned (1:1 ratio) to ablation of RRa followed by modified circumferential PV ablation (mapping group; n=41) or modified circumferential PV ablation alone (control group; n=40). The primary end point was freedom from arrhythmic recurrences at 1 year. In total, 81 persistent AF patients (74% male; mean age, 61.7±10.6 years) underwent mapping/ablation procedure. The regions exhibiting RRa were 479 in 81 patients (5.9±2.4 RRa per patient): 232 regions in the mapping group (n=41) and 247 in the control group (n=40). Overall, 185 of 479 (39%) RRas were identified within the PVs, whereas 294 of 479 (61%) in non-PV regions. Mapping-guided ablation resulted in higher arrhythmia termination rate when compared with conventional strategy (25/41, 61% versus 12/40, 30%; P<0.007). Total radiofrequency duration (P=0.38), mapping (P=0.46), and fluoroscopy times (P=0.69) were not significantly different between the groups. No major procedure-related adverse events occurred. After 1 year, 73.2% of mapping group patients were free from recurrences versus 50% of control group (P=0.03). CONCLUSIONS Targeted ablation of regions showing RRa provided an adjunctive benefit in terms of arrhythmia freedom at 1-year follow-up in the treatment of persistent AF. These findings might support a patient-tailored strategy in subjects with nonparoxysmal AF and should be confirmed by additional larger, randomized, multicenter studies. CLINICAL TRIAL REGISTRATION URL: https://www.clinicaltrials.gov. Unique identifier NCT02571218.
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Affiliation(s)
- Carlo Pappone
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.).
| | - Giuseppe Ciconte
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Gabriele Vicedomini
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Jan O Mangual
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Wenwen Li
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Manuel Conti
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Luigi Giannelli
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Felicia Lipartiti
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Luke McSpadden
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Kyungmoo Ryu
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Marco Guazzi
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Lorenzo Menicanti
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
| | - Vincenzo Santinelli
- From the Department of Arrhythmology and Electrophysiology (C.P., G.C., G.V., M.C., L.G., F.L., V.S.), Department of Cardiac Surgery (L.M.), and Heart Failure Unit (M.G.), IRCCS Policlinico San Donato, San Donato Milanese, Italy; and Abbott, Sylmar, Los Angeles, CA (J.O.M., W.L., L.M., K.R.)
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Mangual JO, Kraigher-Krainer E, De Luca A, Toncelli L, Shah A, Solomon S, Galanti G, Domenichini F, Pedrizzetti G. Comparative numerical study on left ventricular fluid dynamics after dilated cardiomyopathy. J Biomech 2013; 46:1611-7. [DOI: 10.1016/j.jbiomech.2013.04.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 04/15/2013] [Accepted: 04/15/2013] [Indexed: 10/26/2022]
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Mangual JO, De Luca A, Toncelli L, Domenichini F, Galanti G, Pedrizzetti G. Three-dimensional reconstruction of the functional strain-line pattern in the left ventricle from 3-dimensional echocardiography. Circ Cardiovasc Imaging 2013; 5:808-9. [PMID: 23169983 DOI: 10.1161/circimaging.112.979385] [Citation(s) in RCA: 11] [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] [Indexed: 11/16/2022]
Affiliation(s)
- Jan O Mangual
- Department of Civil and Environmental Engineering, University of Florence, Florence, Italy.
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Mangual JO, Föll D, Jung B, Pedrizzetti G, Kheradvar A. Aging Does Not Affect Radial Viscoelastic Behavior of the Left Ventricle. Cardiology 2013; 125:38-49. [DOI: 10.1159/000348871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 02/06/2013] [Indexed: 11/19/2022]
Abstract
<b><i>Objectives:</i></b> This study investigates the effect of aging on the radial viscoelastic behavior of the left ventricle (LV) based on a previously validated model that uses myocardial tissue phase mapping (TPM) of cine phase-contrast MRI. <b><i>Methods:</i></b> Previous studies suggest that aging remarkably influences regional myocardial motion, mostly myocardial velocities in both radial and long-axis directions. However, the effect of aging on cardiac viscoelasticity, which exhibits time-dependent strain, has not been elucidated yet. In this study, myocardial velocity and displacement mapping of the LV was performed using TPM in 39 healthy subjects divided into three age groups. The viscoelasticity parameters were obtained for each segment of the LV and compared among the studied groups. <b><i>Results:</i></b> The analyses showed that myocardial elasticity ranged from approximately 20 to -20 dyne/cm<sup>2</sup> during a cardiac cycle, and the myocardial viscous-damping component ranged from -1 to 1 dyne × s/cm<sup>2</sup>. Overall, no statistically significant difference was observed in the viscoelasticity components among the subjects in the different age groups (p > 0.05). <b><i>Conclusion:</i></b> Myocardial viscoelastic behavior of the LV in radial direction was found to be considerably similar in pattern and magnitude among the studied subjects of different age groups with no statistically significant difference, despite the fact that the regional myocardial velocities change due to aging.
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Pedrizzetti G, Kraigher-Krainer E, De Luca A, Caracciolo G, Mangual JO, Shah A, Toncelli L, Domenichini F, Tonti G, Galanti G, Sengupta PP, Narula J, Solomon S. Functional strain-line pattern in the human left ventricle. Phys Rev Lett 2012; 109:048103. [PMID: 23006111 DOI: 10.1103/physrevlett.109.048103] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Indexed: 06/01/2023]
Abstract
Analysis of deformations in terms of principal directions appears well suited for biological tissues that present an underlying anatomical structure of fiber arrangement. We applied this concept here to study deformation of the beating heart in vivo analyzing 30 subjects that underwent accurate three-dimensional echocardiographic recording of the left ventricle. Results show that strain develops predominantly along the principal direction with a much smaller transversal strain, indicating an underlying anisotropic, one-dimensional contractile activity. The strain-line pattern closely resembles the helical anatomical structure of the heart muscle. These findings demonstrate that cardiac contraction occurs along spatially variable paths and suggest a potential clinical significance of the principal strain concept for the assessment of mechanical cardiac function. The same concept can help in characterizing the relation between functional and anatomical properties of biological tissues, as well as fiber-reinforced engineered materials.
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Mangual JO, Domenichini F, Pedrizzetti G. Describing the highly three dimensional Right Ventricle flow. Ann Biomed Eng 2012; 40:1790-801. [PMID: 22396043 DOI: 10.1007/s10439-012-0540-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Accepted: 02/28/2012] [Indexed: 10/28/2022]
Abstract
Visualization of the three-dimensional flow within the Right Ventricle (RV) is a challenging issue due to the fully three-dimensional geometry of the ventricular cavity. To date proper characterization and quantification of the RV flow still remains incomplete, and techniques that can be easily applied to current medical imaging are scarce. A method for simulating the highly complex, multi directional flow within the RV is presented by coupling 4D echocardiography imaging with numerical simulations based on the Immersed Boundaries Method (IBM). A novel formulation for accurately computing the space-time distribution of the blood residence time inside the cavity is introduced. Results showed an initial compact vortex forming past the tricuspid orifice at early diastole that quickly breaks into a weakly turbulent flow pattern and rearranges, during systole, into a peculiar stream-wise vortex spinning out towards the pulmonary orifice. This arrangement is maintained when the Ejection Fraction (EF) is reduced from 58 to 32%. The average blood transit time is found to scale almost inversely proportional to the EF. A careful analysis of the residence time permitted to assess the relative significance of the different flow components (from the direct flow, with a residence time less than one heartbeat, to the residual volume, that stagnates in the ventricle) and their distribution in space.
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Affiliation(s)
- J O Mangual
- Dipartimento di Ingegneria Civile e Ambientale, Università di Firenze, Via S. Marta 3, 50139 Florence, Italy
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Avilés MO, Mangual JO, Ebner AD, Ritter JA. Isolated swine heart ventricle perfusion model for implant assisted-magnetic drug targeting. Int J Pharm 2008; 361:202-8. [DOI: 10.1016/j.ijpharm.2008.05.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Revised: 05/21/2008] [Accepted: 05/21/2008] [Indexed: 11/25/2022]
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