1
|
Bayer JD, Sobota V, Bear LR, Haïssaguerre M, Vigmond EJ. A His bundle pacing protocol for suppressing ventricular arrhythmia maintenance and improving defibrillation efficacy. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2024; 253:108239. [PMID: 38823116 DOI: 10.1016/j.cmpb.2024.108239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 05/18/2024] [Accepted: 05/21/2024] [Indexed: 06/03/2024]
Abstract
BACKGROUND The excitable gap (EG), defined as the excitable tissue between two subsequent wavefronts of depolarization, is critical for maintaining reentry that underlies deadly ventricular arrhythmias. EG in the His-Purkinje Network (HPN) plays an important role in the maintenance of electrical wave reentry that underlies these arrhythmias. OBJECTIVE To determine if rapid His bundle pacing (HBP) during reentry reduces the amount of EG in the HPN and ventricular myocardium to suppress reentry maintenance and/or improve defibrillation efficacy. METHODS In a virtual human biventricular model, reentry was initiated with rapid line pacing followed by HBP delivered for 3, 6, or 9 s at pacing cycle lengths (PCLs) ranging from 10 to 300 ms (n=30). EG was calculated independently for the HPN and myocardium over each PCL. Defibrillation efficacy was assessed for each PCL by stimulating myocardial surface EG with delays ranging from 0.25 to 9 s (increments of 0.25 s, n=36) after the start of HBP. Defibrillation was successful if reentry terminated within 1 s after EG stimulation. This defibrillation protocol was repeated without HBP. To test the approach under different pathological conditions, all protocols were repeated in the model with right (RBBB) or left (LBBB) bundle branch block. RESULTS Compared to without pacing, HBP for >3 seconds reduced average EG in the HPN and myocardium across a broad range of PCLs for the default, RBBB, and LBBB models. HBP >6 seconds terminated reentrant arrhythmia by converting HPN activation to a sinus rhythm behavior in the default (6/30 PCLs) and RBBB (7/30 PCLs) models. Myocardial EG stimulation during HBP increased the number of successful defibrillation attempts by 3%-19% for 30/30 PCLs in the default model, 3%-6% for 14/30 PCLs in the RBBB model, and 3%-11% for 27/30 PCLs in the LBBB model. CONCLUSION HBP can reduce the amount of excitable gap and suppress reentry maintenance in the HPN and myocardium. HBP can also improve the efficacy of low-energy defibrillation approaches targeting excitable myocardium. HBP during reentrant arrhythmias is a promising anti-arrhythmic and defibrillation strategy.
Collapse
Affiliation(s)
- Jason D Bayer
- IHU Liryc, Electrophysiology and Heart Modeling Institute, fondation Bordeaux Université, 33600, Pessac-Bordeaux, France; University of Bordeaux, Institut de Mathématiques de Bordeaux, UMR 5251, 33400, Talence, France.
| | - Vladimír Sobota
- IHU Liryc, Electrophysiology and Heart Modeling Institute, fondation Bordeaux Université, 33600, Pessac-Bordeaux, France; University of Bordeaux, Institut de Mathématiques de Bordeaux, UMR 5251, 33400, Talence, France
| | - Laura R Bear
- IHU Liryc, Electrophysiology and Heart Modeling Institute, fondation Bordeaux Université, 33600, Pessac-Bordeaux, France
| | - Michel Haïssaguerre
- IHU Liryc, Electrophysiology and Heart Modeling Institute, fondation Bordeaux Université, 33600, Pessac-Bordeaux, France; Haut-Lévêque Cardiology Hospital, University Hospital Center (CHU) of Bordeaux, Pessac, France
| | - Edward J Vigmond
- IHU Liryc, Electrophysiology and Heart Modeling Institute, fondation Bordeaux Université, 33600, Pessac-Bordeaux, France; University of Bordeaux, Institut de Mathématiques de Bordeaux, UMR 5251, 33400, Talence, France
| |
Collapse
|
2
|
Camps J, Berg LA, Wang ZJ, Sebastian R, Riebel LL, Doste R, Zhou X, Sachetto R, Coleman J, Lawson B, Grau V, Burrage K, Bueno-Orovio A, Weber Dos Santos R, Rodriguez B. Digital twinning of the human ventricular activation sequence to Clinical 12-lead ECGs and magnetic resonance imaging using realistic Purkinje networks for in silico clinical trials. Med Image Anal 2024; 94:103108. [PMID: 38447244 DOI: 10.1016/j.media.2024.103108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 03/08/2024]
Abstract
Cardiac in silico clinical trials can virtually assess the safety and efficacy of therapies using human-based modelling and simulation. These technologies can provide mechanistic explanations for clinically observed pathological behaviour. Designing virtual cohorts for in silico trials requires exploiting clinical data to capture the physiological variability in the human population. The clinical characterisation of ventricular activation and the Purkinje network is challenging, especially non-invasively. Our study aims to present a novel digital twinning pipeline that can efficiently generate and integrate Purkinje networks into human multiscale biventricular models based on subject-specific clinical 12-lead electrocardiogram and magnetic resonance recordings. Essential novel features of the pipeline are the human-based Purkinje network generation method, personalisation considering ECG R wave progression as well as QRS morphology, and translation from reduced-order Eikonal models to equivalent biophysically-detailed monodomain ones. We demonstrate ECG simulations in line with clinical data with clinical image-based multiscale models with Purkinje in four control subjects and two hypertrophic cardiomyopathy patients (simulated and clinical QRS complexes with Pearson's correlation coefficients > 0.7). Our methods also considered possible differences in the density of Purkinje myocardial junctions in the Eikonal-based inference as regional conduction velocities. These differences translated into regional coupling effects between Purkinje and myocardial models in the monodomain formulation. In summary, we demonstrate a digital twin pipeline enabling simulations yielding clinically consistent ECGs with clinical CMR image-based biventricular multiscale models, including personalised Purkinje in healthy and cardiac disease conditions.
Collapse
Affiliation(s)
- Julia Camps
- University of Oxford, Oxford, United Kingdom.
| | | | | | | | | | - Ruben Doste
- University of Oxford, Oxford, United Kingdom
| | - Xin Zhou
- University of Oxford, Oxford, United Kingdom
| | - Rafael Sachetto
- Universidade Federal de São João del Rei, São João del Rei, MG, Brazil
| | | | - Brodie Lawson
- Queensland University of Technology, Brisbane, Australia
| | | | - Kevin Burrage
- University of Oxford, Oxford, United Kingdom; Queensland University of Technology, Brisbane, Australia
| | | | | | | |
Collapse
|
3
|
Li T, Marashly Q, Kim JA, Li N, Chelu MG. Cardiac conduction diseases: understanding the molecular mechanisms to uncover targets for future treatments. Expert Opin Ther Targets 2024; 28:385-400. [PMID: 38700451 DOI: 10.1080/14728222.2024.2351501] [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: 11/18/2023] [Accepted: 05/01/2024] [Indexed: 05/05/2024]
Abstract
INTRODUCTION The cardiac conduction system (CCS) is crucial for maintaining adequate cardiac frequency at rest and modulation during exercise. Furthermore, the atrioventricular node and His-Purkinje system are essential for maintaining atrioventricular and interventricular synchrony and consequently maintaining an adequate cardiac output. AREAS COVERED In this review article, we examine the anatomy, physiology, and pathophysiology of the CCS. We then discuss in detail the most common genetic mutations and the molecular mechanisms of cardiac conduction disease (CCD) and provide our perspectives on future research and therapeutic opportunities in this field. EXPERT OPINION Significant advancement has been made in understanding the molecular mechanisms of CCD, including the recognition of the heterogeneous signaling at the subcellular levels of sinoatrial node, the involvement of inflammatory and autoimmune mechanisms, and the potential impact of epigenetic regulations on CCD. However, the current treatment of CCD manifested as bradycardia still relies primarily on cardiovascular implantable electronic devices (CIEDs). On the other hand, an If specific inhibitor was developed to treat inappropriate sinus tachycardia and sinus tachycardia in heart failure patients with reduced ejection fraction. More work is needed to translate current knowledge into pharmacologic or genetic interventions for the management of CCDs.
Collapse
Affiliation(s)
- Tingting Li
- Department of Medicine (Section of Cardiovascular Research), Baylor College of Medicine, Houston, TX, USA
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Qussay Marashly
- Department of Cardiology, Montefiore Medical Center, New York, NY, USA
| | - Jitae A Kim
- Division of CardiovasculMedicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Na Li
- Department of Medicine (Section of Cardiovascular Research), Baylor College of Medicine, Houston, TX, USA
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Mihail G Chelu
- Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
- Department of Medicine (Division of Cardiology), Baylor College of Medicine, Houston, TX, USA
- Division of Cardiology, Baylor St. Luke's Medical Center, Houston, TX, USA
- Division of Cardiology, Texas Heart Institute, Houston, TX, USA
| |
Collapse
|
4
|
Pavri BB. To the Editor- Alternate interpretation of left bundle branch potential. Heart Rhythm 2024; 21:505. [PMID: 38142833 DOI: 10.1016/j.hrthm.2023.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 11/08/2023] [Indexed: 12/26/2023]
Affiliation(s)
- Behzad B Pavri
- Division of Cardiology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania.
| |
Collapse
|
5
|
Nogami A, Komatsu Y, Talib AK, Phanthawimol W, Naeemah QJ, Haruna T, Morishima I. Purkinje-Related Ventricular Tachycardia and Ventricular Fibrillation: Solved and Unsolved Questions. JACC Clin Electrophysiol 2023; 9:2172-2196. [PMID: 37498247 DOI: 10.1016/j.jacep.2023.05.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 05/05/2023] [Accepted: 05/24/2023] [Indexed: 07/28/2023]
Abstract
Of the monomorphic ventricular tachycardias, there are 4 specific tachycardias related to the Purkinje system: 1) idiopathic verapamil-sensitive fascicular ventricular tachycardia (FVT); 2) non-re-entrant FVT; 3) bundle branch re-entry and interfascicular re-entry; and 4) Purkinje-mediated VT in structural heart disease. Verapamil-sensitive FVT is classified into 4 types according to the location of the circuit: 1) left posterior type; 2) left anterior type; 3) left upper septal type;and 4) reverse type. And, in the left anterior and posterior types, there are septal and papillary muscle subtypes. Although macro-re-entry has been reported to be the mechanism underlying verapamil-sensitive FVT, recording the entire circuit is challenging. One possible reason is that the Purkinje-muscle junction may penetrate the myocardial layer as a part of the circuit. The Purkinje network may thus play an important role in the initiation and maintenance of ventricular fibrillation. Further, it has been reported that the development and the abnormalities of the Purkinje system are associated with the arrhythmogenesis of ventricular fibrillation. Furthermore, it has been reported that catheter ablation of trigger ventricular premature complexes, and/or "de-networking" of the Purkinje system, can be used as electrical bailout therapy. There is a hypothesis that the intramural Purkinje system is involved in the generation of J waves. Nevertheless, as there are still unresolved issues that must be debated and accurately analyzed, this review aims to discuss the solved and unsolved questions related to Purkinje-related arrhythmias.
Collapse
Affiliation(s)
- Akihiko Nogami
- Department of Cardiology, Institute of Medicine, University of Tsukuba, Tsukuba, Japan; Institute of Arrhythmia, Tokyo Heart Rhythm Hospital, Tokyo, Japan.
| | - Yuki Komatsu
- Department of Cardiology, Institute of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Ahmed Karim Talib
- Department of Cardiology, Institute of Medicine, University of Tsukuba, Tsukuba, Japan; Faculty of Medicine, University of Kufa, Najaf, Iraq
| | - Wipat Phanthawimol
- Department of Cardiology, Institute of Medicine, University of Tsukuba, Tsukuba, Japan; Cardiac Electrophysiology Unit, Division of Cardiology, Central Chest Institute of Thailand, Nonthaburi, Thailand
| | - Qasim J Naeemah
- Department of Cardiology, Institute of Medicine, University of Tsukuba, Tsukuba, Japan; Faculty of Medicine, University of Kufa, Najaf, Iraq
| | - Tetsuya Haruna
- Cardiovascular Center, Medical Research Institute Kitano Hospital, Osaka, Japan
| | - Itsuro Morishima
- Department of Cardiology, Ogaki Municipal Hospital, Ogaki, Japan
| |
Collapse
|
6
|
Meiburg R, Rijks JHJ, Beela AS, Bressi E, Grieco D, Delhaas T, Luermans JGLM, Prinzen FW, Vernooy K, Lumens J. Comparison of novel ventricular pacing strategies using an electro-mechanical simulation platform. Europace 2023; 25:euad144. [PMID: 37306315 PMCID: PMC10259067 DOI: 10.1093/europace/euad144] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/06/2023] [Indexed: 06/13/2023] Open
Abstract
AIMS Focus of pacemaker therapy is shifting from right ventricular (RV) apex pacing (RVAP) and biventricular pacing (BiVP) to conduction system pacing. Direct comparison between the different pacing modalities and their consequences to cardiac pump function is difficult, due to the practical implications and confounding variables. Computational modelling and simulation provide the opportunity to compare electrical, mechanical, and haemodynamic consequences in the same virtual heart. METHODS AND RESULTS Using the same single cardiac geometry, electrical activation maps following the different pacing strategies were calculated using an Eikonal model on a three-dimensional geometry, which were then used as input for a lumped mechanical and haemodynamic model (CircAdapt). We then compared simulated strain, regional myocardial work, and haemodynamic function for each pacing strategy. Selective His-bundle pacing (HBP) best replicated physiological electrical activation and led to the most homogeneous mechanical behaviour. Selective left bundle branch (LBB) pacing led to good left ventricular (LV) function but significantly increased RV load. RV activation times were reduced in non-selective LBB pacing (nsLBBP), reducing RV load but increasing heterogeneity in LV contraction. LV septal pacing led to a slower LV and more heterogeneous LV activation than nsLBBP, while RV activation was similar. BiVP led to a synchronous LV-RV, but resulted in a heterogeneous contraction. RVAP led to the slowest and most heterogeneous contraction. Haemodynamic differences were small compared to differences in local wall behaviour. CONCLUSION Using a computational modelling framework, we investigated the mechanical and haemodynamic outcome of the prevailing pacing strategies in hearts with normal electrical and mechanical function. For this class of patients, nsLBBP was the best compromise between LV and RV function if HBP is not possible.
Collapse
Affiliation(s)
- Roel Meiburg
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 40, 6200 MD, Maastricht, The Netherlands
| | - Jesse H J Rijks
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center+ (MUMC+), Maastricht, The Netherlands
| | - Ahmed S Beela
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 40, 6200 MD, Maastricht, The Netherlands
- Department of Cardiovascular Diseases, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Edoardo Bressi
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center+ (MUMC+), Maastricht, The Netherlands
- Department of Cardiovascular Sciences, Policlinico Casilino of Rome, Rome, Italy
| | - Domenico Grieco
- Department of Cardiovascular Sciences, Policlinico Casilino of Rome, Rome, Italy
| | - Tammo Delhaas
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 40, 6200 MD, Maastricht, The Netherlands
| | - Justin G LM Luermans
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center+ (MUMC+), Maastricht, The Netherlands
- Department of Cardiology, Radboud University Medical Centre (Radboudumc), Nijmegen, The Netherlands
| | - Frits W Prinzen
- Department of Physiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Kevin Vernooy
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center+ (MUMC+), Maastricht, The Netherlands
| | - Joost Lumens
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 40, 6200 MD, Maastricht, The Netherlands
| |
Collapse
|
7
|
Hirahara AM, Khan MS, Gharbia O, Lange M, Ishidoya Y, Smego D, Ranjan R, Stoddard GJ, Selzman C, Dosdall DJ. Antitachycardia pacing at the His bundle is safer than conventional right ventricular antitachycardia pacing in a canine myocardial ischemic injury model. J Cardiovasc Electrophysiol 2023; 34:1249-1256. [PMID: 37125623 PMCID: PMC10259204 DOI: 10.1111/jce.15916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 04/04/2023] [Accepted: 04/18/2023] [Indexed: 05/02/2023]
Abstract
INTRODUCTION Antitachycardia pacing (ATP) is used to terminate ventricular tachycardia (VT) by delivering rapid, low energy pacing to the right ventricle (RV). Unfortunately, ATP is not effective against all VT episodes and can result in adverse outcomes, such as VT acceleration and degeneration into ventricular fibrillation (VF). Improving ATP is therefore desirable. Our objective was to compare the efficacy and safety of ATP delivered at the His bundle to traditional ATP. METHODS Six dogs were anesthetized and pacing leads were implanted in the RV and His bundle. The left anterior descending artery was occluded for 2 h to create an ischemic injury. In a study 4-7 days later, a 128-electrode sock was placed snugly around the ventricles and VT was induced using rapid pacing. ATP was delivered from either the His bundle or RV lead, then attempted at the other location if unsuccessful. Success rates and instances of VT acceleration and degeneration into VF were calculated. RESULTS We induced 83 runs of VT and attempted ATP 128 times. RV ATP was successful in 36% of attempts; His ATP was successful in 38% of attempts. RV ATP resulted in significantly more adverse outcomes. RV and His ATP induced VT acceleration in 9% and 3% of trains, respectively, and induced degeneration into VF in 5% and 1% of trains, respectively. CONCLUSION His bundle ATP is safer, but not significantly more effective, than RV ATP.
Collapse
Affiliation(s)
- Annie M Hirahara
- Department of Biomedical Engineering, University of Utah, 36 S Wasatch Drive Salt Lake City, Utah, 84112 USA
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 S 2000 E Salt Lake City, Utah, 84112-5000 USA
| | - Muhammad S Khan
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 S 2000 E Salt Lake City, Utah, 84112-5000 USA
| | - Omar Gharbia
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 S 2000 E Salt Lake City, Utah, 84112-5000 USA
| | - Matthias Lange
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 S 2000 E Salt Lake City, Utah, 84112-5000 USA
| | - Yuki Ishidoya
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 S 2000 E Salt Lake City, Utah, 84112-5000 USA
| | - Douglas Smego
- Department of Surgery, Division of Cardiothoracic Surgery, 30 N 1900 E Salt Lake City, Utah, 84132 USA
| | - Ravi Ranjan
- Department of Biomedical Engineering, University of Utah, 36 S Wasatch Drive Salt Lake City, Utah, 84112 USA
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 S 2000 E Salt Lake City, Utah, 84112-5000 USA
- Department of Internal Medicine, Division of Cardiothoracic Surgery, 30 N 1900 E Salt Lake City, Utah 84132 USA
| | - Gregory J Stoddard
- Clinical and Translational Science Institute, University of Utah, 375 Chipeta Way A, Salt Lake City, Utah, 84108 USA
| | - Craig Selzman
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 S 2000 E Salt Lake City, Utah, 84112-5000 USA
- Department of Surgery, Division of Cardiothoracic Surgery, 30 N 1900 E Salt Lake City, Utah, 84132 USA
| | - Derek J Dosdall
- Department of Biomedical Engineering, University of Utah, 36 S Wasatch Drive Salt Lake City, Utah, 84112 USA
- Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, 95 S 2000 E Salt Lake City, Utah, 84112-5000 USA
- Department of Surgery, Division of Cardiothoracic Surgery, 30 N 1900 E Salt Lake City, Utah, 84132 USA
- Department of Internal Medicine, Division of Cardiothoracic Surgery, 30 N 1900 E Salt Lake City, Utah 84132 USA
| |
Collapse
|
8
|
Ezzeddine FM, Ward RC, Asirvatham SJ, DeSimone CV. Mapping and ablation of ventricular fibrillation substrate. J Interv Card Electrophysiol 2023:10.1007/s10840-022-01454-z. [PMID: 36598715 DOI: 10.1007/s10840-022-01454-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/09/2022] [Indexed: 01/05/2023]
Abstract
Ventricular fibrillation (VF) is a life-threatening arrhythmia and a common cause of sudden cardiac death (SCD). A basic understanding of its mechanistic underpinning is crucial for enhancing our knowledge to develop innovative mapping and ablation techniques for this lethal rhythm. Significant advances in our understanding of VF have been made especially in the basic science and pre-clinical experimental realms. However, these studies have not yet translated into a robust clinical approach to identify and successfully ablate both the structural and functional substrate of VF. In this review, we aim to (1) provide a conceptual framework of VF and an overview of the data supporting the spatiotemporal dynamics of VF, (2) review experimental approaches to mapping VF to elucidate drivers and substrate for maintenance with a focus on the His-Purkinje system, (3) discuss current approaches using catheter ablation to treat VF, and (4) highlight current unknowns and gaps in the field where future work is necessary to transform the clinical landscape.
Collapse
Affiliation(s)
- Fatima M Ezzeddine
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Robert Charles Ward
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Samuel J Asirvatham
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Christopher V DeSimone
- Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
| |
Collapse
|
9
|
Choi BR, Ziv O, Salama G. Conduction delays across the specialized conduction system of the heart: Revisiting atrioventricular node (AVN) and Purkinje-ventricular junction (PVJ) delays. Front Cardiovasc Med 2023; 10:1158480. [PMID: 37153461 PMCID: PMC10154624 DOI: 10.3389/fcvm.2023.1158480] [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: 02/03/2023] [Accepted: 03/14/2023] [Indexed: 05/09/2023] Open
Abstract
Background and significance The specialized conduction system (SCS) of the heart was extensively studied to understand the synchronization of atrial and ventricular contractions, the large atrial to His bundle (A-H) delay through the atrioventricular node (AVN), and delays between Purkinje (P) and ventricular (V) depolarization at distinct junctions (J), PVJs. Here, we use optical mapping of perfused rabbit hearts to revisit the mechanism that explains A-H delay and the role of a passive electrotonic step-delay at the boundary between atria and the AVN. We further visualize how the P anatomy controls papillary activation and valve closure before ventricular activation. Methods Rabbit hearts were perfused with a bolus (100-200 µl) of a voltage-sensitive dye (di4ANEPPS), blebbistatin (10-20 µM for 20 min) then the right atrial appendage and ventricular free-wall were cut to expose the AVN, P fibers (PFs), the septum, papillary muscles, and the endocardium. Fluorescence images were focused on a CMOS camera (SciMedia) captured at 1K-5 K frames/s from 100 × 100 pixels. Results AP propagation across the AVN-His (A-H) exhibits distinct patterns of delay and conduction blocks during S1-S2 stimulation. Refractory periods were 81 ± 9, 90 ± 21, 185 ± 15 ms for Atrial, AVN, and His, respectively. A large delay (>40 ms) occurs between atrial and AVN activation that increased during rapid atrial pacing contributing to the development of Wenckebach periodicity followed by delays within the AVN through slow or blocked conduction. The temporal resolution of the camera allowed us to identify PVJs by detecting doublets of AP upstrokes. PVJ delays were heterogeneous, fastest in PVJ that immediately trigger ventricular APs (3.4 ± 0.8 ms) and slow in regions where PF appear insulated from the neighboring ventricular myocytes (7.8 ± 2.4 ms). Insulated PF along papillary muscles conducted APs (>2 m/s), then triggered papillary muscle APs (<1 m/s), followed by APs firing of septum and endocardium. The anatomy of PFs and PVJs produced activation patterns that control the sequence of contractions ensuring that papillary contractions close the tricuspid valve 2-5 ms before right ventricular contractions. Conclusions The specialized conduction system can be accessed optically to investigate the electrical properties of the AVN, PVJ and activation patterns in physiological and pathological conditions.
Collapse
Affiliation(s)
- Bum-Rak Choi
- Department of Medicine, Rhode Island Hospital and Brown University, Providence, RI, United States
| | - Ohad Ziv
- Department of Medicine, Rhode Island Hospital and Brown University, Providence, RI, United States
| | - Guy Salama
- Department of Medicine, Heart and Vascular Institute, University of Pittsburgh, Pittsburgh, PA, United States
- Correspondence: Guy Salama
| |
Collapse
|
10
|
Huang J, Zhao Y, Yang L, Liu Q. Clinical observation of radiofrequency ablation for premature ventricular contractions originating from uncommon His-Purkinje sites. J Interv Card Electrophysiol 2022:10.1007/s10840-022-01428-1. [DOI: 10.1007/s10840-022-01428-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 11/15/2022] [Indexed: 11/24/2022]
Abstract
Abstract
Background
Radiofrequency catheter ablation (RFCA) of premature ventricular contractions (PVCs) originating from common locations such as the proximal and middle fascicles of the His-Purkinje system (HPS) has been established as an effective therapy. This report aims to highlight the electrophysiological properties and RFCA of PVCs originating from uncommon locations of the HPS.
Methods
Among 57 patients with fascicular PVCs, 3 with fascicular PVCs originating from uncommon sites were retrospectively analyzed.
Results
We identified three patients with PVCs originating separately from diseased fascicles, the dead-end tract (DET), and the distal fascicle. In contrast to PVCs originating from the proximal and medial fascicles, the fascicular potentials could not be recorded at the target sites of patients with PVCs originating from diseased fascicles or the distal fascicle during sinus rhythm. However, these PVCs were successfully ablated from the HPS, guided by recording their earliest fascicular potentials in PVCs. PVCs originating from the DET are morphologically consistent with those originating from the proximal left anterior fascicle or the distal left bundle branch. The corresponding tiny sharp potential of the DET could be mapped, and RFCA of the right coronary cusp achieved successful suppression of PVCs.
Conclusions
The knowledge of the different electrophysiological characteristics of fascicular PVCs originating from uncommon locations can contribute to precise mapping and ablation. For such arrhythmia, the target site for successful ablation should be identified by earliest fascicular potential.
Collapse
|
11
|
Wang Y, Zhu H, Hou X, Wang Z, Zou F, Qian Z, Wei Y, Wang X, Zhang L, Li X, Liu Z, Xue S, Qin C, Zeng J, Li H, Wu H, Ma H, Ellenbogen KA, Gold MR, Fan X, Zou J. Randomized Trial of Left Bundle Branch vs Biventricular Pacing for Cardiac Resynchronization Therapy. J Am Coll Cardiol 2022; 80:1205-1216. [PMID: 36137670 DOI: 10.1016/j.jacc.2022.07.019] [Citation(s) in RCA: 139] [Impact Index Per Article: 69.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/02/2022] [Accepted: 07/01/2022] [Indexed: 11/17/2022]
Abstract
BACKGROUND Left bundle branch pacing (LBBP) is the most rapidly growing conduction system pacing technique that is capable of correcting intrinsic left bundle branch block (LBBB). As such, it is potentially an optimal alternative to cardiac resynchronization therapy (CRT) with biventricular pacing (BiVP). OBJECTIVES The authors sought to compare the efficacy of LBBP-CRT with BiVP-CRT in patients with heart failure and reduced left ventricular ejection fraction (LVEF). METHODS This is a prospective, randomized trial of patients with nonischemic cardiomyopathy and LBBB with 6-month preplanned follow-up. Crossovers were allowed if LBBP or BiVP were unsuccessful. The primary endpoint was the difference in LVEF improvement between 2 groups. The secondary endpoints included changes in echocardiographic measurements, N-terminal pro-B-type natriuretic peptide (NT-proBNP), New York Heart Association functional class, 6-minute walk distance, QRS duration, and CRT response. RESULTS The study included 40 consecutive patients (20 males, mean age 63.7 years, LVEF 29.7% ± 5.6%). Crossovers occurred in 10% of LBBP-CRT and 20% of BiVP-CRT. All patients completed follow-up. Intention-to-treat analysis showed significantly higher LVEF improvement at 6 months after LBBP-CRT than BiVP-CRT (mean difference: 5.6%; 95% CI: 0.3-10.9; P = 0.039). LBBP-CRT also appeared to have greater reductions in left ventricular end-systolic volume (-24.97 mL; 95% CI: -49.58 to -0.36 mL) and NT-proBNP (-1,071.80 pg/mL; 95% CI: -2,099.40 to -44.20 pg/mL), and comparable changes in New York Heart Association functional class, 6-minute walk distance, QRS duration, and rates of CRT response compared with BiVP-CRT. CONCLUSIONS LBBP-CRT demonstrated greater LVEF improvement than BiVP-CRT in heart failure patients with nonischemic cardiomyopathy and LBBB. (Left Bundle Branch Pacing Versus Biventricular Pacing for Cardiac Resynchronization Therapy [LBBP-RESYNC]; NCT04110431).
Collapse
Affiliation(s)
- Yao Wang
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Haojie Zhu
- Cardiac Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaofeng Hou
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Zhao Wang
- Cardiac Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Fengwei Zou
- Montefiore Medical Center, Bronx, New York, USA
| | - Zhiyong Qian
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Yongyue Wei
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Xiang Wang
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Longyao Zhang
- Department of Biostatistics, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Xiaofei Li
- Cardiac Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhimin Liu
- Cardiac Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Siyuan Xue
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Chaotong Qin
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Jiaxin Zeng
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Hui Li
- Cardiac Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hongping Wu
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Hong Ma
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | | | - Michael R Gold
- Department of Medicine, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Xiaohan Fan
- Cardiac Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
| | - Jiangang Zou
- Department of Cardiology, First Affiliated Hospital, Nanjing Medical University, Nanjing, China; Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing, China.
| | | |
Collapse
|
12
|
Trinidad F, Rubonal F, Rodriguez de Castro I, Pirzadeh I, Gerrah R, Kheradvar A, Rugonyi S. Effect of Blood Flow on Cardiac Morphogenesis and Formation of Congenital Heart Defects. J Cardiovasc Dev Dis 2022; 9:jcdd9090303. [PMID: 36135448 PMCID: PMC9503889 DOI: 10.3390/jcdd9090303] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 11/26/2022] Open
Abstract
Congenital heart disease (CHD) affects about 1 in 100 newborns and its causes are multifactorial. In the embryo, blood flow within the heart and vasculature is essential for proper heart development, with abnormal blood flow leading to CHD. Here, we discuss how blood flow (hemodynamics) affects heart development from embryonic to fetal stages, and how abnormal blood flow solely can lead to CHD. We emphasize studies performed using avian models of heart development, because those models allow for hemodynamic interventions, in vivo imaging, and follow up, while they closely recapitulate heart defects observed in humans. We conclude with recommendations on investigations that must be performed to bridge the gaps in understanding how blood flow alone, or together with other factors, contributes to CHD.
Collapse
Affiliation(s)
- Fernando Trinidad
- Biomedical Engineering Department, University of California, Irvine, CA 92697, USA
| | - Floyd Rubonal
- Biomedical Engineering Department, Oregon Health & Science University, Portland, OR 97239, USA
| | | | - Ida Pirzadeh
- Biomedical Engineering Department, University of California, Irvine, CA 92697, USA
| | - Rabin Gerrah
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Arash Kheradvar
- Biomedical Engineering Department, University of California, Irvine, CA 92697, USA
| | - Sandra Rugonyi
- Biomedical Engineering Department, Oregon Health & Science University, Portland, OR 97239, USA
- Correspondence:
| |
Collapse
|
13
|
Lossi L. Anatomical features for an adequate choice of the experimental animal model in biomedicine: III. Ferret, goat, sheep, and horse. Ann Anat 2022; 244:151978. [PMID: 35787443 DOI: 10.1016/j.aanat.2022.151978] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/17/2022]
Abstract
The anatomical characteristics of each of the many species today employed in biomedical research are very important when selecting the correct animal model(s), especially for conducting translational research. In previous papers, these features have been considered for fish (D'Angelo et al. Ann. Anat, 2016, 205:75), the most common laboratory rodents, rabbits, and pigs (Lossi et al. 2016). I here follow this line of discussion by dealing with the importance of proper knowledge of ferrets, goats, sheep, and horses' main anatomical features in translational research.
Collapse
Affiliation(s)
- Laura Lossi
- University of Turin, Department of Veterinary Sciences, Turin, Italy; INN, Istituto Nazionale di Neuroscienze, Turin, Italy.
| |
Collapse
|
14
|
Boonstra MJ, Roudijk RW, Brummel R, Kassenberg W, Blom LJ, Oostendorp TF, Te Riele ASJM, van der Heijden JF, Asselbergs FW, Loh P, van Dam PM. Modeling the His-Purkinje Effect in Non-invasive Estimation of Endocardial and Epicardial Ventricular Activation. Ann Biomed Eng 2022; 50:343-359. [PMID: 35072885 PMCID: PMC8847268 DOI: 10.1007/s10439-022-02905-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 01/01/2022] [Indexed: 01/10/2023]
Abstract
Inverse electrocardiography (iECG) estimates epi- and endocardial electrical activity from body surface potentials maps (BSPM). In individuals at risk for cardiomyopathy, non-invasive estimation of normal ventricular activation may provide valuable information to aid risk stratification to prevent sudden cardiac death. However, multiple simultaneous activation wavefronts initiated by the His-Purkinje system, severely complicate iECG. To improve the estimation of normal ventricular activation, the iECG method should accurately mimic the effect of the His-Purkinje system, which is not taken into account in the previously published multi-focal iECG. Therefore, we introduce the novel multi-wave iECG method and report on its performance. Multi-wave iECG and multi-focal iECG were tested in four patients undergoing invasive electro-anatomical mapping during normal ventricular activation. In each subject, 67-electrode BSPM were recorded and used as input for both iECG methods. The iECG and invasive local activation timing (LAT) maps were compared. Median epicardial inter-map correlation coefficient (CC) between invasive LAT maps and estimated multi-wave iECG versus multi-focal iECG was 0.61 versus 0.31. Endocardial inter-map CC was 0.54 respectively 0.22. Modeling the His-Purkinje system resulted in a physiologically realistic and robust non-invasive estimation of normal ventricular activation, which might enable the early detection of cardiac disease during normal sinus rhythm.
Collapse
Affiliation(s)
- Machteld J Boonstra
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands.
| | - Rob W Roudijk
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands
- Netherlands Heart Institute, Utrecht, The Netherlands
| | - Rolf Brummel
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands
| | - Wil Kassenberg
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands
| | - Lennart J Blom
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands
| | - Thom F Oostendorp
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Anneline S J M Te Riele
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands
- Netherlands Heart Institute, Utrecht, The Netherlands
| | - Jeroen F van der Heijden
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands
| | - Folkert W Asselbergs
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands
- Institute of Cardiovascular Science, Faculty of Population Health Sciences, University College London, London, UK
- Health Data Research UK and Institute of Health Informatics, University College London, London, UK
| | - Peter Loh
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands.
| | - Peter M van Dam
- Division Heart & Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht University, 3508 GA, Utrecht, The Netherlands
| |
Collapse
|
15
|
Gui Y, Ye L, Wu L, Mai H, Yan Q, Wang L. Clinical Outcomes Associated With His-Purkinje System Pacing vs. Biventricular Pacing, in Cardiac Resynchronization Therapy: A Meta-Analysis. Front Cardiovasc Med 2022; 9:707148. [PMID: 35224028 PMCID: PMC8873383 DOI: 10.3389/fcvm.2022.707148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 01/13/2022] [Indexed: 11/13/2022] Open
Abstract
AimsHis-Purkinje system pacing has recently emerged as an alternative to biventricular pacing (BIVP) in cardiac resynchronization therapy (CRT). The aim of this study was to conduct a meta-analysis comparing the clinical outcomes associated with His-Purkinje system pacing (HPSP) vs. BIVP in patients with heart failure. There is also a comparison of clinical outcomes of His-bundle pacing (HBP) and left bundle branch pacing (LBBP) in the His-Purkinje system.MethodsWe searched the Cochrane Library, Embase, and PubMed, for studies published between January 2010 and October 2021 that compared the clinical outcomes associated with HPSP vs. BIVP and HBP vs. LBBP in HPSP in patients who underwent CRT. The pacing threshold, R-wave amplitudes, QRS duration, New York Heart Association functional (NYHA), left ventricular ejection fraction (LVEF), and LV end-diastolic diameter (LVEDD) of heart failure, at follow-up, were extracted and summarized for meta-analysis.ResultsA total of 18 studies and 1517 patients were included in our analysis. After a follow-up period of 9.3 ± 5.4 months, the HPSP was found to be associated with shorter QRS duration in the CRT population compared to that in the BIVP (SMD, −1.17; 95% CI, −1.56 to −0.78; P < 0.00001; I2 = 74%). No statistical difference was verified between HBP and LBBP on QRS duration (SMD, 0.04; 95% CI, −0.32 to 0.40; P = 0.82; I2 = 84%). In the comparison of HPSP and BIVP, the LBBP subgroup showed improved LVEF (SMD, 0.67; 95% CI, 0.42–0.91; P < 0.00001; I2 = 0%), shorter LVEDD (SMD, 0.59; 95% CI, 0.93–0.26; P = 0.0005; I2 = 0%), and higher New York Heart Association functional class (SMD, −0.65; 95% CI, −0.86 to −0.43; P < 0.00001; I2 = 45%). In terms of pacing threshold and R-wave amplitude clinical outcomes, LBBP has a lower pacing threshold (SMD, 1.25; 95% CI, 1.12–1.39; P < 0.00001; I2 = 47%) and higher R-wave amplitude (MD, −7.88; 95% CI, −8.46 to −7.31; P < 0.00001; I2 = 8%) performance compared to HBP.ConclusionOur meta-analysis showed that the HPSP produced higher LVEF, shorter QRS duration, and higher NYHA functional class in the CRT population than the BIVP as observed on follow-up. LBBP has a lower pacing threshold and higher R-wave amplitude. HPSP may be a new and promising alternative to BIVP in the future.
Collapse
Affiliation(s)
- Yang Gui
- BengBu Medical College, Bengbu, China
| | - Lifang Ye
- Department of Cardiovascular Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Liuyang Wu
- Department of Cardiovascular Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Haohui Mai
- Department of Cardiovascular Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Qiqi Yan
- Department of Cardiovascular Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Lihong Wang
- Department of Cardiovascular Medicine, Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
- *Correspondence: Lihong Wang
| |
Collapse
|
16
|
Sung RK, Boyden PA, Higuchi S, Scheinman M. Diagnosis and Management of Complex Reentrant Arrhythmias Involving the His-Purkinje System. Arrhythm Electrophysiol Rev 2021; 10:190-197. [PMID: 34777824 PMCID: PMC8576512 DOI: 10.15420/aer.2021.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/13/2021] [Indexed: 11/04/2022] Open
Abstract
The His-Purkinje system is a network of bundles and fibres comprised of specialised cells that allow for coordinated, synchronous activation of the ventricles. Although the histology and physiology of the His-Purkinje system have been studied for more than a century, its role in ventricular arrhythmias has recently been discovered with the ongoing elucidation of the mechanisms leading to both benign and life-threatening arrhythmias. Studies of Purkinje-cell electrophysiology show multiple mechanisms responsible for ventricular arrhythmias, including enhanced automaticity, triggered activity and reentry. The variation in functional properties of Purkinje cells in different areas of the His-Purkinje system underlie the propensity for reentry within Purkinje fibres in structurally normal and abnormal hearts. Catheter ablation is an effective therapy in nearly all forms of reentrant arrhythmias involving Purkinje tissue. However, identifying those at risk of developing fascicular arrhythmias is not yet possible. Future research is needed to understand the precise molecular and functional changes resulting in these arrhythmias.
Collapse
Affiliation(s)
| | | | - Satoshi Higuchi
- University of California San Francisco, San Francisco, CA, US
| | | |
Collapse
|
17
|
Plank G, Loewe A, Neic A, Augustin C, Huang YL, Gsell MAF, Karabelas E, Nothstein M, Prassl AJ, Sánchez J, Seemann G, Vigmond EJ. The openCARP simulation environment for cardiac electrophysiology. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 208:106223. [PMID: 34171774 DOI: 10.1016/j.cmpb.2021.106223] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/28/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND AND OBJECTIVE Cardiac electrophysiology is a medical specialty with a long and rich tradition of computational modeling. Nevertheless, no community standard for cardiac electrophysiology simulation software has evolved yet. Here, we present the openCARP simulation environment as one solution that could foster the needs of large parts of this community. METHODS AND RESULTS openCARP and the Python-based carputils framework allow developing and sharing simulation pipelines which automate in silico experiments including all modeling and simulation steps to increase reproducibility and productivity. The continuously expanding openCARP user community is supported by tailored infrastructure. Documentation and training material facilitate access to this complementary research tool for new users. After a brief historic review, this paper summarizes requirements for a high-usability electrophysiology simulator and describes how openCARP fulfills them. We introduce the openCARP modeling workflow in a multi-scale example of atrial fibrillation simulations on single cell, tissue, organ and body level and finally outline future development potential. CONCLUSION As an open simulator, openCARP can advance the computational cardiac electrophysiology field by making state-of-the-art simulations accessible. In combination with the carputils framework, it offers a tailored software solution for the scientific community and contributes towards increasing use, transparency, standardization and reproducibility of in silico experiments.
Collapse
Affiliation(s)
- Gernot Plank
- Gottfried Schatz Research Center, Division of Biophysics, Medical University of Graz, Graz, Austria.
| | - Axel Loewe
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | | | - Christoph Augustin
- Gottfried Schatz Research Center, Division of Biophysics, Medical University of Graz, Graz, Austria
| | - Yung-Lin Huang
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg. Bad Krozingen, Medical Center - University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias A F Gsell
- Gottfried Schatz Research Center, Division of Biophysics, Medical University of Graz, Graz, Austria
| | - Elias Karabelas
- Institute of Mathematics and Scientific Computing, University of Graz, Graz, Austria
| | - Mark Nothstein
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Anton J Prassl
- Gottfried Schatz Research Center, Division of Biophysics, Medical University of Graz, Graz, Austria
| | - Jorge Sánchez
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Gunnar Seemann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg. Bad Krozingen, Medical Center - University of Freiburg, Freiburg, Germany; Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Edward J Vigmond
- IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, F-33600 Pessac-Bordeaux, France; Université Bordeaux, IMB, UMR 5251, F-33400 Talence, France
| |
Collapse
|
18
|
Grandits T, Effland A, Pock T, Krause R, Plank G, Pezzuto S. GEASI: Geodesic-based earliest activation sites identification in cardiac models. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3505. [PMID: 34170082 PMCID: PMC8459297 DOI: 10.1002/cnm.3505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 06/19/2021] [Accepted: 06/22/2021] [Indexed: 05/18/2023]
Abstract
The identification of the initial ventricular activation sequence is a critical step for the correct personalization of patient-specific cardiac models. In healthy conditions, the Purkinje network is the main source of the electrical activation, but under pathological conditions the so-called earliest activation sites (EASs) are possibly sparser and more localized. Yet, their number, location and timing may not be easily inferred from remote recordings, such as the epicardial activation or the 12-lead electrocardiogram (ECG), due to the underlying complexity of the model. In this work, we introduce GEASI (Geodesic-based Earliest Activation Sites Identification) as a novel approach to simultaneously identify all EASs. To this end, we start from the anisotropic eikonal equation modeling cardiac electrical activation and exploit its Hamilton-Jacobi formulation to minimize a given objective function, for example, the quadratic mismatch to given activation measurements. This versatile approach can be extended to estimate the number of activation sites by means of the topological gradient, or fitting a given ECG. We conducted various experiments in 2D and 3D for in-silico models and an in-vivo intracardiac recording collected from a patient undergoing cardiac resynchronization therapy. The results demonstrate the clinical applicability of GEASI for potential future personalized models and clinical intervention.
Collapse
Affiliation(s)
- Thomas Grandits
- Institute of Computer Graphics and VisionTU GrazGrazAustria
- BioTechMed‐GrazGrazAustria
| | - Alexander Effland
- Institute of Computer Graphics and VisionTU GrazGrazAustria
- Silicon Austria Labs (TU Graz SAL DES Lab)GrazAustria
- Institute for Applied MathematicsUniversity of BonnBonnGermany
| | - Thomas Pock
- Institute of Computer Graphics and VisionTU GrazGrazAustria
- BioTechMed‐GrazGrazAustria
| | - Rolf Krause
- Center for Computational Medicine in Cardiology, Euler InstituteUniversità della Svizzera ItalianaLuganoSwitzerland
| | - Gernot Plank
- BioTechMed‐GrazGrazAustria
- Gottfried Schatz Research Center—Division of BiophysicsMedical University of GrazGrazAustria
| | - Simone Pezzuto
- Center for Computational Medicine in Cardiology, Euler InstituteUniversità della Svizzera ItalianaLuganoSwitzerland
| |
Collapse
|
19
|
Barber F, Langfield P, Lozano M, Garcia-Fernandez I, Duchateau J, Hocini M, Haissaguerre M, Vigmond E, Sebastian R. Estimation of Personalized Minimal Purkinje Systems From Human Electro-Anatomical Maps. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:2182-2194. [PMID: 33856987 DOI: 10.1109/tmi.2021.3073499] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The Purkinje system is a heart structure responsible for transmitting electrical impulses through the ventricles in a fast and coordinated way to trigger mechanical contraction. Estimating a patient-specific compatible Purkinje Network from an electro-anatomical map is a challenging task, that could help to improve models for electrophysiology simulations or provide aid in therapy planning, such as radiofrequency ablation. In this study, we present a methodology to inversely estimate a Purkinje network from a patient's electro-anatomical map. First, we carry out a simulation study to assess the accuracy of the method for different synthetic Purkinje network morphologies and myocardial junction densities. Second, we estimate the Purkinje network from a set of 28 electro-anatomical maps from patients, obtaining an optimal conduction velocity in the Purkinje network of 1.95 ± 0.25 m/s, together with the location of their Purkinje-myocardial junctions, and Purkinje network structure. Our results showed an average local activation time error of 6.8±2.2 ms in the endocardium. Finally, using the personalized Purkinje network, we obtained correlations higher than 0.85 between simulated and clinical 12-lead ECGs.
Collapse
|
20
|
Abstract
Computer modeling of the electrophysiology of the heart has undergone significant progress. A healthy heart can be modeled starting from the ion channels via the spread of a depolarization wave on a realistic geometry of the human heart up to the potentials on the body surface and the ECG. Research is advancing regarding modeling diseases of the heart. This article reviews progress in calculating and analyzing the corresponding electrocardiogram (ECG) from simulated depolarization and repolarization waves. First, we describe modeling of the P-wave, the QRS complex and the T-wave of a healthy heart. Then, both the modeling and the corresponding ECGs of several important diseases and arrhythmias are delineated: ischemia and infarction, ectopic beats and extrasystoles, ventricular tachycardia, bundle branch blocks, atrial tachycardia, flutter and fibrillation, genetic diseases and channelopathies, imbalance of electrolytes and drug-induced changes. Finally, we outline the potential impact of computer modeling on ECG interpretation. Computer modeling can contribute to a better comprehension of the relation between features in the ECG and the underlying cardiac condition and disease. It can pave the way for a quantitative analysis of the ECG and can support the cardiologist in identifying events or non-invasively localizing diseased areas. Finally, it can deliver very large databases of reliably labeled ECGs as training data for machine learning.
Collapse
|
21
|
Gómez-Torres F, Ruíz-Sauri A. Morphometric analysis of the His bundle (atrioventricular fascicle) in humans and other animal species. Histological and immunohistochemical study. Vet Res Commun 2021; 45:319-327. [PMID: 34244914 DOI: 10.1007/s11259-021-09812-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/27/2021] [Indexed: 10/20/2022]
Abstract
The His bundle is a part of the specialized electrical conduction system that provides a connection between the atrial and ventricular myocardial compartments in both normal and abnormal hearts. The aim of this study was to perform a morphometric analysis of His bundle characteristics of in humans, dogs, horses and pigs and compare them in these studied species. Histological sections of 5 μm thickness were obtained and stained with hematoxylin-eosin and Masson's trichrome; the desmin and periodic acid-Schiff methods were also used for precise identification of cells. The His bundle was found to be longer in horses (2.85 ± 1.02 mm) and pigs (1.77 ± 0.9 mm) than in dogs (1.53 ± 0.8 mm) or humans, in which it was shortest (1.06 ± 0.6 mm). The area and diameters in His bundle cells, were significantly larger in pigs and horses than in humans (p < 0.001) or dogs (p < 0.001). We found two organizational patterns of His bundle components: group I, with large cells and a high amount of collagen fibers in ungulates (pigs and horses); and group II, with smaller cells and lower abundance of collagen fibers in humans and dogs. Documenting cell size variations in the His bundle allows us not only to identify this bundle by histological or anatomical location but also to differentiate these cells from others such as nodal or Purkinje cells. Our analysis revealed that His bundle cells have discrete identities based on their morphometric and histological characteristics.
Collapse
Affiliation(s)
- Fabián Gómez-Torres
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, 1st floor, Av. de Blasco Ibáñez, 15, 46010, Valencia, Spain.,Department of Basic Sciences, School of Medicine, Universidad Industrial de Santander, Cra, 32 # 29-31, 68002, Bucaramanga, Colombia
| | - Amparo Ruíz-Sauri
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, 1st floor, Av. de Blasco Ibáñez, 15, 46010, Valencia, Spain. .,INCLIVA Biomedical Research Institute, Av. de Blasco Ibáñez, 17, 46010, Valencia, Spain.
| |
Collapse
|
22
|
Mantri S, Wu SM, Goodyer WR. Molecular Profiling of the Cardiac Conduction System: the Dawn of a New Era. Curr Cardiol Rep 2021; 23:103. [PMID: 34196831 DOI: 10.1007/s11886-021-01536-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/17/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE OF REVIEW Recent technological advances have led to an increased ability to define the gene expression profile of the cardiac conduction system (CCS). Here, we review the most salient studies to emerge in recent years and discuss existing gaps in our knowledge as well as future areas of investigation. RECENT FINDINGS Molecular profiling of the CCS spans several decades. However, the advent of high-throughput sequencing strategies has allowed for the discovery of unique transcriptional programs of the many diverse CCS cell types. The CCS, a diverse structure with significant inter- and intra-component cellular heterogeneity, is essential to the normal function of the heart. Progress in transcriptomic profiling has improved the resolution and depth of characterization of these unique and clinically relevant CCS cell types. Future studies leveraging this big data will play a crucial role in improving our understanding of CCS development and function as well as translating these findings into tangible translational tools for the improved detection, prevention, and treatment of cardiac arrhythmias.
Collapse
Affiliation(s)
- Sruthi Mantri
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Sean M Wu
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA.,Division of Pediatric Cardiology, Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA.,Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - William R Goodyer
- Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, 94305, USA. .,Division of Pediatric Cardiology, Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA. .,Division of Pediatric Cardiology, Electrophysiology, Department of Pediatrics, Lucile Packard Children's Hospital, Stanford University School of Medicine, Room G1105 Lokey Stem Cell Research Building, 265 Campus Drive, Stanford, CA, 94305, USA.
| |
Collapse
|
23
|
Bakir AA, Al Abed A, Lovell NH, Dokos S. Multiphysics computational modelling of the cardiac ventricles. IEEE Rev Biomed Eng 2021; 15:309-324. [PMID: 34185649 DOI: 10.1109/rbme.2021.3093042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Development of cardiac multiphysics models has progressed significantly over the decades and simulations combining multiple physics interactions have become increasingly common. In this review, we summarise the progress in this field focusing on various approaches of integrating ventricular structures. electrophysiological properties, myocardial mechanics, as well as incorporating blood hemodynamics and the circulatory system. Common coupling approaches are discussed and compared, including the advantages and shortcomings of each. Currently used strategies for patient-specific implementations are highlighted and potential future improvements considered.
Collapse
|
24
|
Gómez-Torres F, Estupiñán HY, Ruíz-Sauri A. Identification to cardiac conduction cells in humans and pigs according to their zonal distribution, using histological, immunohistochemical and morphometric study. Res Vet Sci 2021; 138:137-147. [PMID: 34144281 DOI: 10.1016/j.rvsc.2021.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 05/23/2021] [Accepted: 06/07/2021] [Indexed: 10/21/2022]
Abstract
Histologically, the cardiac conduction network is formed of electrically isolated subendocardial fibers that comprise specialized cells with fewer myofibrils and mitochondria than cardiomyocytes. Our aim is to uncover regional variations of cardiac conduction fibers through histological and morphometric study in a porcine and human model. We analyzed five male adult human hearts and five male pig hearts. The left ventricles were dissected and sectioned in the axial plane into three parts: basal, middle third and apex regions. Cardiac conduction fibers study was carried out using hematoxylin-eosin and Masson's trichrome staining, and cardiac conduction cells and their junctions were identified using desmin, and a PAS method. Cardiac conduction fibers were difficult to pinpoint in humans, mostly showing a darker color or equal to cardiomyocytes. Cardiac conduction fibers in humans were in the subendocardium and in pigs in the myocardium and subendocardium. Cardiac conduction fibers were located mainly in the septal region in both humans and pigs. In our morphometric analysis, we were able to determine that cardiac conduction cells in humans (18.52 +/- 5.41 μm) and pigs (21.32 +/- 6.45 μm) were large, compared to cardiomyocytes. Conduction fiber-myocardial junctions were present in 10% in humans and 24.2% in pigs. The performance of immunohistochemical methods made it possible to improve the identification of cardiac conduction cells in the species studied. Study of cardiac conduction fibers and cells and their myocardial junctions is vital to gain insight into their normal distribution in the species analyzed, and thus advance the use of pigs in experimental models of the cardiac conduction system in humans.
Collapse
Affiliation(s)
- Fabián Gómez-Torres
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Av. de Blasco Ibáñez, 15, 46010 Valencia, Spain; Department of Basic Sciences, Medicine School, Universidad Industrial de Santander, Cra 32 # 29-31, 68002 Bucaramanga, Colombia.
| | - H Yesid Estupiñán
- Department of Basic Sciences, Medicine School, Universidad Industrial de Santander, Cra 32 # 29-31, 68002 Bucaramanga, Colombia; Department of Laboratory Medicine, Clinical Research Center, Karolinska Institute, Karolinska University Hospital Huddinge, SE-141 86 Huddinge, Sweden.
| | - Amparo Ruíz-Sauri
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Av. de Blasco Ibáñez, 15, 46010 Valencia, Spain; INCLIVA Biomedical Research Institute, Av. de Blasco Ibáñez, 17, 46010 Valencia, Spain.
| |
Collapse
|
25
|
Electro-Mechanical Whole-Heart Digital Twins: A Fully Coupled Multi-Physics Approach. MATHEMATICS 2021. [DOI: 10.3390/math9111247] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mathematical models of the human heart are evolving to become a cornerstone of precision medicine and support clinical decision making by providing a powerful tool to understand the mechanisms underlying pathophysiological conditions. In this study, we present a detailed mathematical description of a fully coupled multi-scale model of the human heart, including electrophysiology, mechanics, and a closed-loop model of circulation. State-of-the-art models based on human physiology are used to describe membrane kinetics, excitation-contraction coupling and active tension generation in the atria and the ventricles. Furthermore, we highlight ways to adapt this framework to patient specific measurements to build digital twins. The validity of the model is demonstrated through simulations on a personalized whole heart geometry based on magnetic resonance imaging data of a healthy volunteer. Additionally, the fully coupled model was employed to evaluate the effects of a typical atrial ablation scar on the cardiovascular system. With this work, we provide an adaptable multi-scale model that allows a comprehensive personalization from ion channels to the organ level enabling digital twin modeling.
Collapse
|
26
|
Gómez-Torres FA, Estupiñán HY, Ruíz-Saurí A. Morphometric analysis of cardiac conduction fibers in horses and dogs, a comparative histological and immunohistochemical study with findings in human hearts. Res Vet Sci 2021; 135:200-216. [PMID: 33618179 DOI: 10.1016/j.rvsc.2021.02.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/04/2021] [Accepted: 02/14/2021] [Indexed: 11/28/2022]
Abstract
The principal function of the ventricular conduction system is rapid electrical activation of the ventricles. The aim of this study is to conduct a morphometric study to pinpoint the morphological parameters that define cardiac conduction cells, allowing us to distinguish them from other cells. Five male horse hearts and five male dog hearts were used in the study. The hearts were fixed in a 5% formaldehyde solution. Histological sections of 5 μm thickness were acquired and stained with hematoxylin-eosin and Masson's trichrome and cardiac conduction cells and their junctions were identified by desmin, connexin 40 and a PAS method. We found statistically significant differences in cardiac conduction fibers density and thickness, which was much higher in horses than in dogs (p = 0.000 for both values). By comparing the measured parameters of the cells in both species, we determined that cardiac conduction cells area and diameters were greater in horses than in dogs (p = 0.000 for all values). In dogs there are more junctions (30.8%) than in horses (26.1%), a statistically significant difference (p = 0.041). Our findings regarding the cardiac conduction fibers distribution in the animal species studied becomes new knowledge that contributes to the morphological study of this component of the cardiac conduction system and also makes it possible to locate exactly the site with the highest density of cardiac conduction fibers as a contribution to the cardiological study of these structures that lead to the prevention of ventricular arrhythmias and the identification of their treatment site.
Collapse
Affiliation(s)
- F A Gómez-Torres
- Department of Pathology, Faculty of Medicine, 1st floor, Universitat de Valencia, Av. de Blasco Ibáñez, 15, 46010 Valencia, Spain; Department of Basic Sciences, School of Medicine, Universidad Industrial de Santander, Cra 32 # 29-31, 68002 Bucaramanga, Colombia.
| | - H Y Estupiñán
- Department of Basic Sciences, School of Medicine, Universidad Industrial de Santander, Cra 32 # 29-31, 68002 Bucaramanga, Colombia; Department of Laboratory Medicine, Clinical Research Center, Karolinska Institute, Karolinska University Hospital Huddinge, SE-141 86 Huddinge, Sweden.
| | - A Ruíz-Saurí
- Department of Pathology, Faculty of Medicine, 1st floor, Universitat de Valencia, Av. de Blasco Ibáñez, 15, 46010 Valencia, Spain; INCLIVA Biomedical Research Institute, Av. de Blasco Ibáñez, 17, 46010 Valencia, Spain.
| |
Collapse
|
27
|
Wang Y, Gu K, Qian Z, Hou X, Chen X, Qiu Y, Jiang Z, Zhang X, Wu H, Chen M, Zou J. The efficacy of left bundle branch area pacing compared with biventricular pacing in patients with heart failure: A matched case-control study. J Cardiovasc Electrophysiol 2020; 31:2068-2077. [PMID: 32562442 DOI: 10.1111/jce.14628] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/29/2020] [Accepted: 06/14/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Left bundle branch area pacing (LBBAP) was reported to improve cardiac function by correcting complete left bundle branch block (CLBBB). Our study aimed to compare the efficacy of LBBAP and biventricular pacing (BIVP) in heart failure patients with CLBBB. METHODS Ten patients prospectively underwent LBBAP (LBB-CRT group) and 30 patients received BIVP (BIV-CRT group) were matched using propensity score matching. LBBAP was achieved by the trans-interventricular septum method. Echocardiography, electrocardiogram, NYHA classification, and blood B-type natriuretic peptide concentration were evaluated at preimplantation and at 6-month follow up. CRT response was defined as at least 15% decrease in left ventricular end-systolic volume. RESULTS In the LBB-CRT group, CLBBB were successfully corrected by LBBAP with no complications. QRS duration (QRSd) significantly decreased after implantation in both groups, and the decrease of QRSd in the LBB-CRT group was significantly greater than that in the BIV-CRT group (60.80 ± 20.09 vs. 33.00 ± 21.48 ms, p = .0009). The echocardiographic measurements including left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular ejection fraction significantly improved after 6 months in both groups. The response rate was significantly higher in LBB-CRT group than BIV-CRT group (100.00% vs. 63.33%, p = .038). The percentage of patients in New York Heart Association classification Grades I and II was significantly higher in the LBB-CRT group compared with that in the BIV-CRT group (median 1.5 vs. 2.0, p = .029) at 6-month follow-up. CONCLUSIONS It is effective and safe to correct CLBBB with LBBAP in heart failure patients. Compared with BIVP, LBBAP can better optimize electrical synchrony and improve cardiac function.
Collapse
Affiliation(s)
- Yao Wang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Kai Gu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zhiyong Qian
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xiaofeng Hou
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xing Chen
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yuanhao Qiu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zeyu Jiang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Xinwei Zhang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Hongping Wu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Minglong Chen
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jiangang Zou
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| |
Collapse
|
28
|
Strocchi M, Augustin CM, Gsell MAF, Karabelas E, Neic A, Gillette K, Razeghi O, Prassl AJ, Vigmond EJ, Behar JM, Gould J, Sidhu B, Rinaldi CA, Bishop MJ, Plank G, Niederer SA. A publicly available virtual cohort of four-chamber heart meshes for cardiac electro-mechanics simulations. PLoS One 2020; 15:e0235145. [PMID: 32589679 PMCID: PMC7319311 DOI: 10.1371/journal.pone.0235145] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 06/09/2020] [Indexed: 12/12/2022] Open
Abstract
Computational models of the heart are increasingly being used in the development of devices, patient diagnosis and therapy guidance. While software techniques have been developed for simulating single hearts, there remain significant challenges in simulating cohorts of virtual hearts from multiple patients. To facilitate the development of new simulation and model analysis techniques by groups without direct access to medical data, image analysis techniques and meshing tools, we have created the first publicly available virtual cohort of twenty-four four-chamber hearts. Our cohort was built from heart failure patients, age 67±14 years. We segmented four-chamber heart geometries from end-diastolic (ED) CT images and generated linear tetrahedral meshes with an average edge length of 1.1±0.2mm. Ventricular fibres were added in the ventricles with a rule-based method with an orientation of -60° and 80° at the epicardium and endocardium, respectively. We additionally refined the meshes to an average edge length of 0.39±0.10mm to show that all given meshes can be resampled to achieve an arbitrary desired resolution. We ran simulations for ventricular electrical activation and free mechanical contraction on all 1.1mm-resolution meshes to ensure that our meshes are suitable for electro-mechanical simulations. Simulations for electrical activation resulted in a total activation time of 149±16ms. Free mechanical contractions gave an average left ventricular (LV) and right ventricular (RV) ejection fraction (EF) of 35±1% and 30±2%, respectively, and a LV and RV stroke volume (SV) of 95±28mL and 65±11mL, respectively. By making the cohort publicly available, we hope to facilitate large cohort computational studies and to promote the development of cardiac computational electro-mechanics for clinical applications.
Collapse
Affiliation(s)
- Marina Strocchi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| | | | | | - Elias Karabelas
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| | | | - Karli Gillette
- Institute of Biophysics, Medical University of Graz, Graz, Steiermark, Austria
| | - Orod Razeghi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| | - Anton J. Prassl
- Institute of Biophysics, Medical University of Graz, Graz, Steiermark, Austria
| | - Edward J. Vigmond
- IHU Liryc, Electrophysiology and Heart Modeling Institute, fondation Bordeaux Université, F-33600 Pessac- Bordeaux, France
- University of Bordeaux, IMB, UMR 5251, F-33400 Talence, France
| | - Jonathan M. Behar
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, City of London, United Kingdom
| | - Justin Gould
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, City of London, United Kingdom
| | - Baldeep Sidhu
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, City of London, United Kingdom
| | - Christopher A. Rinaldi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
- Guy’s and St Thomas’ NHS Foundation Trust, London, City of London, United Kingdom
| | - Martin J. Bishop
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| | - Gernot Plank
- Institute of Biophysics, Medical University of Graz, Graz, Steiermark, Austria
| | - Steven A. Niederer
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, City of London, United Kingdom
| |
Collapse
|
29
|
Kojic M, Milosevic M, Simic V, Milicevic B, Geroski V, Nizzero S, Ziemys A, Filipovic N, Ferrari M. Smeared Multiscale Finite Element Models for Mass Transport and Electrophysiology Coupled to Muscle Mechanics. Front Bioeng Biotechnol 2020; 7:381. [PMID: 31921800 PMCID: PMC6914730 DOI: 10.3389/fbioe.2019.00381] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 11/15/2019] [Indexed: 11/22/2022] Open
Abstract
Mass transport represents the most fundamental process in living organisms. It includes delivery of nutrients, oxygen, drugs, and other substances from the vascular system to tissue and transport of waste and other products from cells back to vascular and lymphatic network and organs. Furthermore, movement is achieved by mechanical forces generated by muscles in coordination with the nervous system. The signals coming from the brain, which have the character of electrical waves, produce activation within muscle cells. Therefore, from a physics perspective, there exist a number of physical fields within the body, such as velocities of transport, pressures, concentrations of substances, and electrical potential, which is directly coupled to biochemical processes of transforming the chemical into mechanical energy and further internal forces for motion. The overall problems of mass transport and electrophysiology coupled to mechanics can be investigated theoretically by developing appropriate computational models. Due to the enormous complexity of the biological system, it would be almost impossible to establish a detailed computational model for the physical fields related to mass transport, electrophysiology, and coupled fields. To make computational models feasible for applications, we here summarize a concept of smeared physical fields, with coupling among them, and muscle mechanics, which includes dependence on the electrical potential. Accuracy of the smeared computational models, also with coupling to muscle mechanics, is illustrated with simple example, while their applicability is demonstrated on a liver model with tumors present. The last example shows that the introduced methodology is applicable to large biological systems.
Collapse
Affiliation(s)
- Milos Kojic
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX, United States.,Bioengineering Research and Development Center BioIRC Kragujevac, Kragujevac, Serbia.,Serbian Academy of Sciences and Arts, Belgrade, Serbia
| | - Miljan Milosevic
- Bioengineering Research and Development Center BioIRC Kragujevac, Kragujevac, Serbia.,Faculty of Information Technologies, Belgrade Metropolitan University, Belgrade, Serbia
| | - Vladimir Simic
- Bioengineering Research and Development Center BioIRC Kragujevac, Kragujevac, Serbia
| | - Bogdan Milicevic
- Bioengineering Research and Development Center BioIRC Kragujevac, Kragujevac, Serbia
| | - Vladimir Geroski
- Bioengineering Research and Development Center BioIRC Kragujevac, Kragujevac, Serbia
| | - Sara Nizzero
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX, United States.,Applied Physics Graduate Program, Rice University, Houston, TX, United States
| | - Arturas Ziemys
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX, United States
| | - Nenad Filipovic
- Faculty for Engineering Sciences, University of Kragujevac, Kragujevac, Serbia
| | - Mauro Ferrari
- Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX, United States
| |
Collapse
|
30
|
Wang Y, Cai L, Luo X, Ying W, Gao H. Simulation of action potential propagation based on the ghost structure method. Sci Rep 2019; 9:10927. [PMID: 31358816 PMCID: PMC6662858 DOI: 10.1038/s41598-019-47321-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 07/15/2019] [Indexed: 12/30/2022] Open
Abstract
In this paper, a ghost structure (GS) method is proposed to simulate the monodomain model in irregular computational domains using finite difference without regenerating body-fitted grids. In order to verify the validity of the GS method, it is first used to solve the Fitzhugh-Nagumo monodomain model in rectangular and circular regions at different states (the stationary and moving states). Then, the GS method is used to simulate the propagation of the action potential (AP) in transverse and longitudinal sections of a healthy human heart, and with left bundle branch block (LBBB). Finally, we analyze the AP and calcium concentration under healthy and LBBB conditions. Our numerical results show that the GS method can accurately simulate AP propagation with different computational domains either stationary or moving, and we also find that LBBB will cause the left ventricle to contract later than the right ventricle, which in turn affects synchronized contraction of the two ventricles.
Collapse
Affiliation(s)
- Yongheng Wang
- NPU-UoG International Cooperative Lab for Computation and Application in Cardiology, Northwestern Polytechnical University, Xi'an, 710129, China.
| | - Li Cai
- NPU-UoG International Cooperative Lab for Computation and Application in Cardiology, Northwestern Polytechnical University, Xi'an, 710129, China. .,Xi'an Key Laboratory of Scientific Computation and Applied Statistics, Northwestern Polytechnical University, Xi'an, 710129, China.
| | - Xiaoyu Luo
- School of Mathematics and Statistics, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Wenjun Ying
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hao Gao
- School of Mathematics and Statistics, University of Glasgow, Glasgow, G12 8QQ, UK
| |
Collapse
|
31
|
Goodyer WR, Beyersdorf BM, Paik DT, Tian L, Li G, Buikema JW, Chirikian O, Choi S, Venkatraman S, Adams EL, Tessier-Lavigne M, Wu JC, Wu SM. Transcriptomic Profiling of the Developing Cardiac Conduction System at Single-Cell Resolution. Circ Res 2019; 125:379-397. [PMID: 31284824 DOI: 10.1161/circresaha.118.314578] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
RATIONALE The cardiac conduction system (CCS) consists of distinct components including the sinoatrial node, atrioventricular node, His bundle, bundle branches, and Purkinje fibers. Despite an essential role for the CCS in heart development and function, the CCS has remained challenging to interrogate because of inherent obstacles including small cell numbers, large cell-type heterogeneity, complex anatomy, and difficulty in isolation. Single-cell RNA-sequencing allows for genome-wide analysis of gene expression at single-cell resolution. OBJECTIVE Assess the transcriptional landscape of the entire CCS at single-cell resolution by single-cell RNA-sequencing within the developing mouse heart. METHODS AND RESULTS Wild-type, embryonic day 16.5 mouse hearts (n=6 per zone) were harvested and 3 zones of microdissection were isolated, including: Zone I-sinoatrial node region; Zone II-atrioventricular node/His region; and Zone III-bundle branch/Purkinje fiber region. Tissue was digested into single-cell suspensions, cells isolated, mRNA reverse transcribed, and barcoded before high-throughput sequencing and bioinformatics analyses. Single-cell RNA-sequencing was performed on over 22 000 cells, and all major cell types of the murine heart were successfully captured including bona fide clusters of cells consistent with each major component of the CCS. Unsupervised weighted gene coexpression network analysis led to the discovery of a host of novel CCS genes, a subset of which were validated using fluorescent in situ hybridization as well as whole-mount immunolabeling with volume imaging (iDISCO+) in 3 dimensions on intact mouse hearts. Further, subcluster analysis unveiled isolation of distinct CCS cell subtypes, including the clinically relevant but poorly characterized transitional cells that bridge the CCS and surrounding myocardium. CONCLUSIONS Our study represents the first comprehensive assessment of the transcriptional profiles from the entire CCS at single-cell resolution and provides a characterization in the context of development and disease.
Collapse
Affiliation(s)
- William R Goodyer
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA.,Department of Pediatrics (W.R.G., S.M.W.), Stanford University, CA
| | - Benjamin M Beyersdorf
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA.,Department of Cardiovascular Surgery, Institute Insure (Institute for Translational Cardiac Surgery), German Heart Center Munich at the Technical University of Munich, Germany (B.M.B.)
| | - David T Paik
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA
| | - Lei Tian
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA
| | - Guang Li
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA.,Department of Developmental Biology, University of Pittsburgh School of Medicine, PA (G.L.)
| | - Jan W Buikema
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA.,Department of Cardiology, Utrecht Regenerative Medicine Center, University Medical Center Utrecht, Utrecht University, The Netherlands (J.W.B.)
| | - Orlando Chirikian
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA.,Department of Molecular, Cellular, and Developmental Biology, UC Santa Barbara, CA (O.C.)
| | - Shannon Choi
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA
| | - Sneha Venkatraman
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA
| | - Eliza L Adams
- Department of Biology (E.L.A., M.T.-L.), Stanford University, CA
| | | | - Joseph C Wu
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA.,Department of Medicine, Cardiovascular Medicine (J.C.W., S.M.W.), Stanford University School of Medicine, CA
| | - Sean M Wu
- From the Cardiovascular Institute (W.R.G., B.M.B., D.T.P., L.T., G.L., J.W.B., O.C., S.C., S.V., J.C.W., S.M.W.), Stanford University School of Medicine, CA.,Department of Medicine, Cardiovascular Medicine (J.C.W., S.M.W.), Stanford University School of Medicine, CA.,Department of Pediatrics (W.R.G., S.M.W.), Stanford University, CA
| |
Collapse
|
32
|
Lee AWC, Nguyen UC, Razeghi O, Gould J, Sidhu BS, Sieniewicz B, Behar J, Mafi-Rad M, Plank G, Prinzen FW, Rinaldi CA, Vernooy K, Niederer S. A rule-based method for predicting the electrical activation of the heart with cardiac resynchronization therapy from non-invasive clinical data. Med Image Anal 2019; 57:197-213. [PMID: 31326854 PMCID: PMC6746621 DOI: 10.1016/j.media.2019.06.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/20/2019] [Accepted: 06/27/2019] [Indexed: 12/13/2022]
Abstract
Background Cardiac Resynchronization Therapy (CRT) is one of the few effective treatments for heart failure patients with ventricular dyssynchrony. The pacing location of the left ventricle is indicated as a determinant of CRT outcome. Objective Patient specific computational models allow the activation pattern following CRT implant to be predicted and this may be used to optimize CRT lead placement. Methods In this study, the effects of heterogeneous cardiac substrate (scar, fast endocardial conduction, slow septal conduction, functional block) on accurately predicting the electrical activation of the LV epicardium were tested to determine the minimal detail required to create a rule based model of cardiac electrophysiology. Non-invasive clinical data (CT or CMR images and 12 lead ECG) from eighteen patients from two centers were used to investigate the models. Results Validation with invasive electro-anatomical mapping data identified that computer models with fast endocardial conduction were able to predict the electrical activation with a mean distance errors of 9.2 ± 0.5 mm (CMR data) or (CT data) 7.5 ± 0.7 mm. Conclusion This study identified a simple rule-based fast endocardial conduction model, built using non-invasive clinical data that can be used to rapidly and robustly predict the electrical activation of the heart. Pre-procedural prediction of the latest electrically activating region to identify the optimal LV pacing site could potentially be a useful clinical planning tool for CRT procedures.
Collapse
Affiliation(s)
- A W C Lee
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.
| | - U C Nguyen
- Department of Physiology, Maastricht University Medical Center (MUMC+), Cardiovascular Research Institute Maastricht (CARIM), Maastricht, the Netherlands; Department of Cardiology, Maastricht University Medical Center (MUMC+), Cardiovascular Research Institute Maastricht (CARIM), Maastricht, the Netherlands
| | - O Razeghi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - J Gould
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - B S Sidhu
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - B Sieniewicz
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - J Behar
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom; Bart's Heart Centre, St. Bartholomew's Hospital, London, United Kingdom
| | - M Mafi-Rad
- Department of Cardiology, Maastricht University Medical Center (MUMC+), Cardiovascular Research Institute Maastricht (CARIM), Maastricht, the Netherlands
| | - G Plank
- Department of Biophysics, Medical University of Graz, Graz, Austria
| | - F W Prinzen
- Department of Physiology, Maastricht University Medical Center (MUMC+), Cardiovascular Research Institute Maastricht (CARIM), Maastricht, the Netherlands
| | - C A Rinaldi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - K Vernooy
- Department of Cardiology, Maastricht University Medical Center (MUMC+), Cardiovascular Research Institute Maastricht (CARIM), Maastricht, the Netherlands; Department of Cardiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - S Niederer
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| |
Collapse
|
33
|
Kojic M, Milosevic M, Simic V, Geroski V, Ziemys A, Filipovic N, Ferrari M. Smeared multiscale finite element model for electrophysiology and ionic transport in biological tissue. Comput Biol Med 2019; 108:288-304. [PMID: 31015049 DOI: 10.1016/j.compbiomed.2019.03.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 03/22/2019] [Accepted: 03/23/2019] [Indexed: 10/27/2022]
Abstract
Basic functions of living organisms are governed by the nervous system through bidirectional signals transmitted from the brain to neural networks. These signals are similar to electrical waves. In electrophysiology the goal is to study the electrical properties of biological cells and tissues, and the transmission of signals. From a physics perspective, there exists a field of electrical potential within the living body, the nervous system, extracellular space and cells. Electrophysiological problems can be investigated experimentally and also theoretically by developing appropriate mathematical or computational models. Due to the enormous complexity of biological systems, it would be almost impossible to establish a detailed computational model of the electrical field, even for only a single organ (e.g. heart), including the entirety of cells comprising the neural network. In order to make computational models feasible for practical applications, we here introduce the concept of smeared fields, which represents a generalization of the previously formulated multiscale smeared methodology for mass transport in blood vessels, lymph, and tissue. We demonstrate the accuracy of the smeared finite element computational models for the electric field in numerical examples. The electrical field is further coupled with ionic mass transport within tissue composed of interstitial spaces extracellularly and by cytoplasm and organelles intracellularly. The proposed methodology, which couples electrophysiology and molecular ionic transport, is applicable to a variety of biological systems.
Collapse
Affiliation(s)
- M Kojic
- Houston Methodist Research Institute, The Department of Nanomedicine, 6670 Bertner Ave., R7-117, Houston, TX, 77030, USA; Bioengineering Research and Development Center BioIRC Kragujevac, Prvoslava Stojanovica 6, 3400, Kragujevac, Serbia; Serbian Academy of Sciences and Arts, Knez Mihailova 35, 11000, Belgrade, Serbia.
| | - M Milosevic
- Bioengineering Research and Development Center BioIRC Kragujevac, Prvoslava Stojanovica 6, 3400, Kragujevac, Serbia; Belgrade Metropolitan University, Tadeuša Košćuška 63, 11000, Belgrade, Serbia
| | - V Simic
- Bioengineering Research and Development Center BioIRC Kragujevac, Prvoslava Stojanovica 6, 3400, Kragujevac, Serbia
| | - V Geroski
- Bioengineering Research and Development Center BioIRC Kragujevac, Prvoslava Stojanovica 6, 3400, Kragujevac, Serbia
| | - A Ziemys
- Houston Methodist Research Institute, The Department of Nanomedicine, 6670 Bertner Ave., R7-117, Houston, TX, 77030, USA
| | - N Filipovic
- University of Kragujevac, Faculty for Engineering Sciences, Sestre Janic 6, 34000, Kragujevac, Serbia
| | - M Ferrari
- Houston Methodist Research Institute, The Department of Nanomedicine, 6670 Bertner Ave., R7-117, Houston, TX, 77030, USA
| |
Collapse
|
34
|
Ulysses JN, Berg LA, Cherry EM, Liu BR, Santos RWD, de Barros BG, Rocha BM, de Queiroz RAB. An Optimization-Based Algorithm for the Construction of Cardiac Purkinje Network Models. IEEE Trans Biomed Eng 2018; 65:2760-2768. [DOI: 10.1109/tbme.2018.2815504] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
35
|
Ahmad Bakir A, Al Abed A, Stevens MC, Lovell NH, Dokos S. A Multiphysics Biventricular Cardiac Model: Simulations With a Left-Ventricular Assist Device. Front Physiol 2018; 9:1259. [PMID: 30271353 PMCID: PMC6142745 DOI: 10.3389/fphys.2018.01259] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/21/2018] [Indexed: 11/16/2022] Open
Abstract
Computational models have become essential in predicting medical device efficacy prior to clinical studies. To investigate the performance of a left-ventricular assist device (LVAD), a fully-coupled cardiac fluid-electromechanics finite element model was developed, incorporating electrical activation, passive and active myocardial mechanics, as well as blood hemodynamics solved simultaneously in an idealized biventricular geometry. Electrical activation was initiated using a simplified Purkinje network with one-way coupling to the surrounding myocardium. Phenomenological action potential and excitation-contraction equations were adapted to trigger myocardial contraction. Action potential propagation was formulated within a material frame to emulate gap junction-controlled propagation, such that the activation sequence was independent of myocardial deformation. Passive cardiac mechanics were governed by a transverse isotropic hyperelastic constitutive formulation. Blood velocity and pressure were determined by the incompressible Navier-Stokes formulations with a closed-loop Windkessel circuit governing the circulatory load. To investigate heart-LVAD interaction, we reduced the left ventricular (LV) contraction stress to mimic a failing heart, and inserted a LVAD cannula at the LV apex with continuous flow governing the outflow rate. A proportional controller was implemented to determine the pump motor voltage whilst maintaining pump motor speed. Following LVAD insertion, the model revealed a change in the LV pressure-volume loop shape from rectangular to triangular. At higher pump speeds, aortic ejection ceased and the LV decompressed to smaller end diastolic volumes. After multiple cycles, the LV cavity gradually collapsed along with a drop in pump motor current. The model was therefore able to predict ventricular collapse, indicating its utility for future development of control algorithms and pre-clinical testing of LVADs to avoid LV collapse in recipients.
Collapse
Affiliation(s)
- Azam Ahmad Bakir
- Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW, Australia
| | - Amr Al Abed
- Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW, Australia
| | - Michael C Stevens
- Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW, Australia.,Innovative Cardiovascular Engineering and Technology Laboratory, Critical Care Research Group, The Prince Charles Hospital, Brisbane, QLD, Australia
| | - Nigel H Lovell
- Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW, Australia
| | - Socrates Dokos
- Graduate School of Biomedical Engineering, University of New South Wales, Kensington, NSW, Australia
| |
Collapse
|
36
|
Barber F, García-Fernández I, Lozano M, Sebastian R. Automatic estimation of Purkinje-Myocardial junction hot-spots from noisy endocardial samples: A simulation study. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2018; 34:e2988. [PMID: 29637731 DOI: 10.1002/cnm.2988] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 01/10/2018] [Accepted: 03/23/2018] [Indexed: 05/15/2023]
Abstract
The reconstruction of the ventricular cardiac conduction system (CCS) from patient-specific data is a challenging problem. High-resolution imaging techniques have allowed only the segmentation of proximal sections of the CCS from images acquired ex vivo. In this paper, we present an algorithm to estimate the location of a set of Purkinje-myocardial junctions (PMJs) from electro-anatomical maps, as those acquired during radio-frequency ablation procedures. The method requires a mesh representing the myocardium with local activation time measurements on a subset of nodes. We calculate the backwards propagation of the electrical signal from the measurement points to all the points in the mesh to define a set of candidate PMJs that is iteratively refined. The algorithm has been tested on several Purkinje network configurations, with simulated activation maps, subject to different error amplitudes. The results show that the method is able to build a set of PMJs that explain the observed activation map for different synthetic CCS configurations. In the tests, the average error in the predicted activation time is below the amplitude of the error applied to the data.
Collapse
Affiliation(s)
- Fernando Barber
- Computational Multiscale Simulation Lab (CoMMLab), Departament d'Informàtica, Universitat de València, Burjasot 46100, Spain
| | - Ignacio García-Fernández
- Computational Multiscale Simulation Lab (CoMMLab), Departament d'Informàtica, Universitat de València, Burjasot 46100, Spain
| | - Miguel Lozano
- Computational Multiscale Simulation Lab (CoMMLab), Departament d'Informàtica, Universitat de València, Burjasot 46100, Spain
| | - Rafael Sebastian
- Computational Multiscale Simulation Lab (CoMMLab), Departament d'Informàtica, Universitat de València, Burjasot 46100, Spain
| |
Collapse
|
37
|
Cardone-Noott L, Bueno-Orovio A, Mincholé A, Zemzemi N, Rodriguez B. Human ventricular activation sequence and the simulation of the electrocardiographic QRS complex and its variability in healthy and intraventricular block conditions. Europace 2017; 18:iv4-iv15. [PMID: 28011826 PMCID: PMC5225966 DOI: 10.1093/europace/euw346] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 08/09/2016] [Indexed: 12/01/2022] Open
Abstract
Aims To investigate how variability in activation sequence and passive conduction properties translates into clinical variability in QRS biomarkers, and gain novel physiological knowledge on the information contained in the human QRS complex. Methods and results Multiscale bidomain simulations using a detailed heart-torso human anatomical model are performed to investigate the impact of activation sequence characteristics on clinical QRS biomarkers. Activation sequences are built and validated against experimentally-derived ex vivo and in vivo human activation data. R-peak amplitude exhibits the largest variability in terms of QRS morphology, due to its simultaneous modulation by activation sequence speed, myocardial intracellular and extracellular conductivities, and propagation through the human torso. QRS width, however, is regulated by endocardial activation speed and intracellular myocardial conductivities, whereas QR intervals are only affected by the endocardial activation profile. Variability in the apico-basal location of activation sites on the anterior and posterior left ventricular wall is associated with S-wave progression in limb and precordial leads, respectively, and occasional notched QRS complexes in precordial derivations. Variability in the number of early activation sites successfully reproduces pathological abnormalities of the human conduction system in the QRS complex. Conclusion Variability in activation sequence and passive conduction properties captures and explains a large part of the clinical variability observed in the human QRS complex. Our physiological insights allow for a deeper interpretation of human QRS biomarkers in terms of QRS morphology and location of early endocardial activation sites. This might be used to attain a better patient-specific knowledge of activation sequence from routine body-surface electrocardiograms.
Collapse
Affiliation(s)
- Louie Cardone-Noott
- Department of Computer Science and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford OX1 3QD, UK
| | - Alfonso Bueno-Orovio
- Department of Computer Science and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford OX1 3QD, UK
| | - Ana Mincholé
- Department of Computer Science and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford OX1 3QD, UK
| | - Nejib Zemzemi
- INRIA Bordeaux Sud-Ouest, 200 avenue de la vieille tour, Talence Cedex 33405, France.,IHU Liryc, Electrophysiology and Heart Modeling Institute, foundation Bordeaux Université, F-33600 Pessac Bordeaux, France
| | - Blanca Rodriguez
- Department of Computer Science and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford OX1 3QD, UK
| |
Collapse
|
38
|
Lange M, Palamara S, Lassila T, Vergara C, Quarteroni A, Frangi AF. Improved hybrid/GPU algorithm for solving cardiac electrophysiology problems on Purkinje networks. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33:e2835. [PMID: 27661463 DOI: 10.1002/cnm.2835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 09/15/2016] [Indexed: 06/06/2023]
Abstract
Cardiac Purkinje fibers provide an important pathway to the coordinated contraction of the heart. We present a numerical algorithm for the solution of electrophysiology problems across the Purkinje network that is efficient enough to be used in in silico studies on realistic Purkinje networks with physiologically detailed models of ion exchange at the cell membrane. The algorithm is on the basis of operator splitting and is provided with 3 different implementations: pure CPU, hybrid CPU/GPU, and pure GPU. Compared to our previous work, we modify the explicit gap junction term at network bifurcations to improve its mathematical consistency. Due to this improved consistency of the model, we are able to perform an empirical convergence study against analytical solutions. The study verified that all 3 implementations produce equivalent convergence rates, and shows that the algorithm produces equivalent result across different hardware platforms. Finally, we compare the efficiency of all 3 implementations on Purkinje networks of increasing spatial resolution using membrane models of increasing complexity. Both hybrid and pure GPU implementations outperform the pure CPU implementation, but their relative performance difference depends on the size of the Purkinje network and the complexity of the membrane model used.
Collapse
Affiliation(s)
- M Lange
- CISTIB, Department of Electronic and Electrical Engineering, The University of Sheffield, UK
| | - S Palamara
- MOX, Dipartimento di Matematica, Politecnico di Milano, Italy
| | - T Lassila
- CISTIB, Department of Electronic and Electrical Engineering, The University of Sheffield, UK
| | - C Vergara
- MOX, Dipartimento di Matematica, Politecnico di Milano, Italy
| | - A Quarteroni
- CMCS, Mathematics Institute of Computational Science and Engineering, École Polytechnique Fédérale de Lausanne, Switzerland
| | - A F Frangi
- CISTIB, Department of Electronic and Electrical Engineering, The University of Sheffield, UK
| |
Collapse
|
39
|
Garcia-Bustos V, Sebastian R, Izquierdo M, Molina P, Chorro FJ, Ruiz-Sauri A. A quantitative structural and morphometric analysis of the Purkinje network and the Purkinje-myocardial junctions in pig hearts. J Anat 2017; 230:664-678. [PMID: 28256093 DOI: 10.1111/joa.12594] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2016] [Indexed: 12/20/2022] Open
Abstract
The morpho-functional properties of the distal section of the cardiac Purkinje network (PN) and the Purkinje-myocardial junctions (PMJs) are fundamental to understanding the sequence of electrical activation in the heart. The overall structure of the system has already been described, and several computational models have been developed to gain insight into its involvement in cardiac arrhythmias or its interaction with implantable devices, such as pacemakers. However, anatomical descriptions of the PN in the literature have not enabled enough improvements in the accuracy of anatomical-based electrophysiological simulations of the PN in 3D hearts models. In this work, we study the global distribution and morphological properties of the PN, with special emphasis on the cellular and architectural characterization of its intramural branching structure, mesh-like sub-endocardial network, and the PMJs in adult pig hearts by both histopathological and morphometric evaluation. We have defined three main patterns of PMJ: contact through cell bodies, contact through cell prolongations either thick or piliform, and contact through transitional cells. Moreover, from hundreds of micrographs, we quantified the density of PMJs and provided data for the basal/medial/apical regions, anterior/posterior/septal/lateral regions and myocardial/sub-endocardial distribution. Morphometric variables, such as Purkinje cell density and thickness of the bundles, were also analyzed. After combining the results of these parameters, a different septoanterior distribution in the Purkinje cell density was observed towards the cardiac apex, which is associated with a progressive thinning of the conduction bundles and the posterolateral ascension of intramyocardial terminal scattered fibers. The study of the PMJs revealed a decreasing trend towards the base that may anatomically explain the early apical activation. The anterolateral region contains the greatest number of contacts, followed by the anterior and septal regions. This supports the hypothesis that thin distal Purkinje bundles create a junction-rich network that may be responsible for the quick apical depolarization. The PN then ascends laterally and spreads through the anterior and medial walls up to the base. We have established the first morphometric study of the Purkinje system, and provided quantitative and objective data that facilitate its incorporation into the development of models beyond gross and variable pathological descriptions, and which, after further studies, could be useful in the characterization of pathological processes or therapeutic procedures.
Collapse
Affiliation(s)
- V Garcia-Bustos
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Valencia, Spain
| | - R Sebastian
- Computational Multiscale Simulation Lab, Universitat de Valencia, Valencia, Spain
| | - M Izquierdo
- INCLIVA Biomedical Research Institute, Valencia, Spain.,Cardiology Unit, Hospital Clinico Universitario de Valencia, Valencia, Spain
| | - P Molina
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Valencia, Spain
| | - F J Chorro
- INCLIVA Biomedical Research Institute, Valencia, Spain.,Cardiology Unit, Hospital Clinico Universitario de Valencia, Valencia, Spain
| | - A Ruiz-Sauri
- Department of Pathology, Faculty of Medicine, Universitat de Valencia, Valencia, Spain.,INCLIVA Biomedical Research Institute, Valencia, Spain
| |
Collapse
|
40
|
Kapa S, Gaba P, DeSimone CV, Asirvatham SJ. Fascicular Ventricular Arrhythmias. Circ Arrhythm Electrophysiol 2017; 10:CIRCEP.116.002476. [DOI: 10.1161/circep.116.002476] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 12/15/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Suraj Kapa
- From the Department of Cardiology (S.K., C.V.D., S.J.A.) and Division of Pediatric Cardiology, Department of Pediatrics (S.J.A.), Mayo Clinic College of Medicine, Rochester, MN; and Mayo Clinic Medical School, Rochester, MN (P.G.)
| | - Prakriti Gaba
- From the Department of Cardiology (S.K., C.V.D., S.J.A.) and Division of Pediatric Cardiology, Department of Pediatrics (S.J.A.), Mayo Clinic College of Medicine, Rochester, MN; and Mayo Clinic Medical School, Rochester, MN (P.G.)
| | - Christopher V. DeSimone
- From the Department of Cardiology (S.K., C.V.D., S.J.A.) and Division of Pediatric Cardiology, Department of Pediatrics (S.J.A.), Mayo Clinic College of Medicine, Rochester, MN; and Mayo Clinic Medical School, Rochester, MN (P.G.)
| | - Samuel J. Asirvatham
- From the Department of Cardiology (S.K., C.V.D., S.J.A.) and Division of Pediatric Cardiology, Department of Pediatrics (S.J.A.), Mayo Clinic College of Medicine, Rochester, MN; and Mayo Clinic Medical School, Rochester, MN (P.G.)
| |
Collapse
|
41
|
Gemmell P, Burrage K, Rodríguez B, Quinn TA. Rabbit-specific computational modelling of ventricular cell electrophysiology: Using populations of models to explore variability in the response to ischemia. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 121:169-84. [PMID: 27320382 PMCID: PMC5405055 DOI: 10.1016/j.pbiomolbio.2016.06.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 06/13/2016] [Indexed: 11/04/2022]
Abstract
Computational modelling, combined with experimental investigations, is a powerful method for investigating complex cardiac electrophysiological behaviour. The use of rabbit-specific models, due to the similarities of cardiac electrophysiology in this species with human, is especially prevalent. In this paper, we first briefly review rabbit-specific computational modelling of ventricular cell electrophysiology, multi-cellular simulations including cellular heterogeneity, and acute ischemia. This mini-review is followed by an original computational investigation of variability in the electrophysiological response of two experimentally-calibrated populations of rabbit-specific ventricular myocyte action potential models to acute ischemia. We performed a systematic exploration of the response of the model populations to varying degrees of ischemia and individual ischemic parameters, to investigate their individual and combined effects on action potential duration and refractoriness. This revealed complex interactions between model population variability and ischemic factors, which combined to enhance variability during ischemia. This represents an important step towards an improved understanding of the role that physiological variability may play in electrophysiological alterations during acute ischemia.
Collapse
Affiliation(s)
- Philip Gemmell
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Kevin Burrage
- Department of Computer Science, University of Oxford, Oxford, UK; School of Mathematical Sciences and ARC Centre of Excellence, ACEMS, Queensland University of Technology, Brisbane, Australia
| | - Blanca Rodríguez
- Department of Computer Science, University of Oxford, Oxford, UK
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, 5850 College St, Lab 3F, Halifax, NS B3H 4R2, Canada; School of Biomedical Engineering, Dalhousie University, 5850 College St, Lab 3F, Halifax, NS B3H 4R2, Canada.
| |
Collapse
|
42
|
Early afterdepolarizations promote transmural reentry in ischemic human ventricles with reduced repolarization reserve. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 120:236-48. [PMID: 26850675 PMCID: PMC4821233 DOI: 10.1016/j.pbiomolbio.2016.01.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 01/25/2016] [Accepted: 01/29/2016] [Indexed: 11/24/2022]
Abstract
AIMS Acute ischemia is a major cause of sudden arrhythmic death, further promoted by potassium current blockers. Macro-reentry around the ischemic region and early afterdepolarizations (EADs) caused by electrotonic current have been suggested as potential mechanisms in animal and isolated cell studies. However, ventricular and human-specific arrhythmia mechanisms and their modulation by repolarization reserve remain unclear. The goal of this paper is to unravel multiscale mechanisms underlying the modulation of arrhythmic risk by potassium current (IKr) block in human ventricles with acute regional ischemia. METHODS AND RESULTS A human ventricular biophysically-detailed model, with acute regional ischemia is constructed by integrating experimental knowledge on the electrophysiological ionic alterations caused by coronary occlusion. Arrhythmic risk is evaluated by determining the vulnerable window (VW) for reentry following ectopy at the ischemic border zone. Macro-reentry around the ischemic region is the main reentrant mechanism in the ischemic human ventricle with increased repolarization reserve due to the ATP-sensitive potassium current (IK(ATP)) activation. Prolongation of refractoriness by 4% caused by 30% IKr reduction counteracts the establishment of macro-reentry and reduces the VW for reentry (by 23.5%). However, a further decrease in repolarization reserve (50% IKr reduction) is less anti-arrhythmic despite further prolongation of refractoriness. This is due to the establishment of transmural reentry enabled by electrotonically-triggered EADs in the ischemic border zone. EADs are produced by L-type calcium current (ICaL) reactivation due to prolonged low amplitude electrotonic current injected during the repolarization phase. CONCLUSIONS Electrotonically-triggered EADs are identified as a potential mechanism facilitating intramural reentry in a regionally-ischemic human ventricles model with reduced repolarization reserve.
Collapse
|
43
|
Quinn TA, Ripplinger CM. Recent developments in biophysics & molecular biology of heart rhythm. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 120:1-2. [PMID: 26777585 DOI: 10.1016/j.pbiomolbio.2016.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Canada.
| | | |
Collapse
|
44
|
Csepe TA, Zhao J, Hansen BJ, Li N, Sul LV, Lim P, Wang Y, Simonetti OP, Kilic A, Mohler PJ, Janssen PML, Fedorov VV. Human sinoatrial node structure: 3D microanatomy of sinoatrial conduction pathways. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 120:164-78. [PMID: 26743207 DOI: 10.1016/j.pbiomolbio.2015.12.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 12/10/2015] [Accepted: 12/18/2015] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Despite a century of extensive study on the human sinoatrial node (SAN), the structure-to-function features of specialized SAN conduction pathways (SACP) are still unknown and debated. We report a new method for direct analysis of the SAN microstructure in optically-mapped human hearts with and without clinical history of SAN dysfunction. METHODS Two explanted donor human hearts were coronary-perfused and optically-mapped. Structural analyses of histological sections parallel to epicardium (∼13-21 μm intervals) were integrated with optical maps to create 3D computational reconstructions of the SAN complex. High-resolution fiber fields were obtained using 3D Eigen-analysis of the structure tensor, and used to analyze SACP microstructure with a fiber-tracking approach. RESULTS Optical mapping revealed normal SAN activation of the atria through a lateral SACP proximal to the crista terminalis in Heart #1 but persistent SAN exit block in diseased Heart #2. 3D structural analysis displayed a functionally-observed SAN border composed of fibrosis, fat, and/or discontinuous fibers between SAN and atria, which was only crossed by several branching myofiber tracts in SACP regions. Computational 3D fiber-tracking revealed that myofiber tracts of SACPs created continuous connections between SAN #1 and atria, but in SAN #2, SACP region myofiber tracts were discontinuous due to fibrosis and fat. CONCLUSIONS We developed a new integrative functional, structural and computational approach that allowed for the resolution of the specialized 3D microstructure of human SACPs for the first time. Application of this integrated approach will shed new light on the role of the specialized SAN microanatomy in maintaining sinus rhythm.
Collapse
Affiliation(s)
- Thomas A Csepe
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jichao Zhao
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Brian J Hansen
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Ning Li
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Lidiya V Sul
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Praise Lim
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Yufeng Wang
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Orlando P Simonetti
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, OH, USA; Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Ahmet Kilic
- Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Peter J Mohler
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Paul M L Janssen
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Vadim V Fedorov
- Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
| |
Collapse
|