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Wu X, Hu W, Song L, Chen W, Zhou Y, Zhou L, Ou Z, Qiu Z. Use of acoustic cardiography to assess left ventricular electromechanical synchronization during left bundle branch pacing. Heart Rhythm O2 2023; 4:632-640. [PMID: 37936667 PMCID: PMC10626181 DOI: 10.1016/j.hroo.2023.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023] Open
Abstract
Background Left bundle branch pacing (LBBP) is a physiological pacing that captures the main left bundle or its proximal branch. Electromechanical activation time (EMAT) is an acoustic cardiographic metric that provides a simple method for evaluating left ventricular (LV) synchrony. Prolonged EMAT reflects impaired LV electromechanical coupling. Objective The purpose of this study was to explore whether EMAT can confirm that LBBP produces more satisfactory LV electromechanical synchronization than conventional right ventricular pacing modalities. Methods Patients with standard pacing indications and narrow QRS duration were recruited for this study. Unipolar pacing under 3 different modalities-right ventricular apical pacing (RVAP), right ventricular high septal pacing (RVHSP), and LBBP-were successively performed in each patient. Pacing parameters, echocardiographic characteristics, and acoustic cardiographic parameters at different pacing modalities and during normal rhythm were collected. Results A total of 55 patients were enrolled, and all had successful LBBP. Left ventricular activation time (LVAT) was significantly associated with EMAT, with LVAT vs EMAT correlation coefficient of 0.665 (P <.001). LVAT during LBBP was shorter than that during RVHSP (51.93 ± 2.732 ms vs 85.59 ± 2.240 ms; P <.001). EMAT of LBBP was significantly lower than either RVAP or RVHSP (95.44 ± 1.794 ms vs 143.32 ± 2.376 ms, and 132.22 ± 1.872 ms; both P <.001) but was similar to that of intrinsic rhythm (95.37 ± 2.271 ms; P = .862). Conclusion We found EMAT significantly prolonged in RVHSP and RVAP but not in the LBBP mode. This finding indicates superior electromechanical synchronization in patients having LBBP. EMAT measurement could be an additional method for identifying the ideal pacing position.
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Affiliation(s)
- Xianhao Wu
- Department of Cardiology, Shanghai Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wei Hu
- Department of Cardiology, Shanghai Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lei Song
- Department of Cardiology, Shanghai Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wanlan Chen
- Department of Cardiology, Shanghai Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Zhou
- Department of Cardiology, Shanghai Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lihong Zhou
- Department of Cardiology, Shanghai Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ziming Ou
- Department of Cardiology, Shanghai Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zhaohui Qiu
- Department of Cardiology, Shanghai Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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Trifunović-Zamaklar D, Jovanović I, Vratonjić J, Petrović O, Paunović I, Tešić M, Boričić-Kostić M, Ivanović B. The basic heart anatomy and physiology from the cardiologist's perspective: Toward a better understanding of left ventricular mechanics, systolic, and diastolic function. JOURNAL OF CLINICAL ULTRASOUND : JCU 2022; 50:1026-1040. [PMID: 36218206 DOI: 10.1002/jcu.23316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 06/16/2023]
Abstract
A comprehensive understanding of the cardiac structure-function relationship is essential for proper clinical cardiac imaging. This review summarizes the basic heart anatomy and physiology from the perspective of a heart imager focused on myocardial mechanics. The main issues analyzed are the left ventricular (LV) architecture, the LV myocardial deformation through the cardiac cycle, the LV diastolic function basic parameters and the basic parameters of the LV deformation used in clinical practice for the LV function assessment.
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Affiliation(s)
- Danijela Trifunović-Zamaklar
- Clinic for Cardiology, University Clinical Center of Serbia, Belgrade, Serbia
- School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ivana Jovanović
- Clinic for Cardiology, University Clinical Center of Serbia, Belgrade, Serbia
| | - Jelena Vratonjić
- Clinic for Cardiology, University Clinical Center of Serbia, Belgrade, Serbia
| | - Olga Petrović
- Clinic for Cardiology, University Clinical Center of Serbia, Belgrade, Serbia
- School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Ivana Paunović
- Clinic for Cardiology, University Clinical Center of Serbia, Belgrade, Serbia
| | - Milorad Tešić
- Clinic for Cardiology, University Clinical Center of Serbia, Belgrade, Serbia
- School of Medicine, University of Belgrade, Belgrade, Serbia
| | | | - Branislava Ivanović
- Clinic for Cardiology, University Clinical Center of Serbia, Belgrade, Serbia
- School of Medicine, University of Belgrade, Belgrade, Serbia
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3
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Vergara C, Stella S, Maines M, Africa PC, Catanzariti D, Demattè C, Centonze M, Nobile F, Quarteroni A, Del Greco M. Computational electrophysiology of the coronary sinus branches based on electro-anatomical mapping for the prediction of the latest activated region. Med Biol Eng Comput 2022; 60:2307-2319. [PMID: 35729476 PMCID: PMC9293833 DOI: 10.1007/s11517-022-02610-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 06/07/2022] [Indexed: 01/18/2023]
Abstract
This work dealt with the assessment of a computational tool to estimate the electrical activation in the left ventricle focusing on the latest electrically activated segment (LEAS) in patients with left bundle branch block and possible myocardial fibrosis. We considered the Eikonal-diffusion equation and to recover the electrical activation maps in the myocardium. The model was calibrated by using activation times acquired in the coronary sinus (CS) branches or in the CS solely with an electroanatomic mapping system (EAMS) during cardiac resynchronization therapy (CRT). We applied our computational tool to ten patients founding an excellent accordance with EAMS measures; in particular, the error for LEAS location was less than 4 mm. We also calibrated our model using only information in the CS, still obtaining an excellent agreement with the measured LEAS. The proposed tool was able to accurately reproduce the electrical activation maps and in particular LEAS location in the CS branches, with an almost real-time computational effort, regardless of the presence of myocardial fibrosis, even when information only at CS was used to calibrate the model. This could be useful in the clinical practice since LEAS is often used as a target site for the left lead placement during CRT.
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Affiliation(s)
- Christian Vergara
- LABS, Dipartimento Di Chimica, Materiali E Ingegneria Chimica “Giulio Natta”, Politecnico Di Milano, Piazza Leonardo da Vinci 32, 20233 Milan, Italy
| | - Simone Stella
- Dipartimento Di Matematica, MOX, Politecnico Di Milano, Piazza Leonardo da Vinci 32, 20233 Milan, Italy
| | - Massimiliano Maines
- Department of Cardiology, S. Maria del Carmine Hospital, corso Verona 4, 38068 Rovereto, TN Italy
| | - Pasquale Claudio Africa
- Dipartimento Di Matematica, MOX, Politecnico Di Milano, Piazza Leonardo da Vinci 32, 20233 Milan, Italy
| | - Domenico Catanzariti
- Department of Cardiology, S. Maria del Carmine Hospital, corso Verona 4, 38068 Rovereto, TN Italy
| | - Cristina Demattè
- Department of Cardiology, S. Maria del Carmine Hospital, corso Verona 4, 38068 Rovereto, TN Italy
| | - Maurizio Centonze
- U.O. Di Radiologia Di Borgo-Pergine, Borgo Valsugana Hospital, viale Vicenza 9, 38051 Borgo Valsugana, (TN) Italy
| | - Fabio Nobile
- Institute of Mathematics, CSQI, École Polytechnique Fédérale de Lausanne, Route Cantonale, 1015 Lausanne, Switzerland
| | - Alfio Quarteroni
- Dipartimento Di Matematica, MOX, Politecnico Di Milano, Piazza Leonardo da Vinci 32, 20233 Milan, Italy
- Institute of Mathematics, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Maurizio Del Greco
- Department of Cardiology, S. Maria del Carmine Hospital, corso Verona 4, 38068 Rovereto, TN Italy
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4
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Duport O, Le Rolle V, Galli E, Danan D, Darrigrand E, Donal E, Hernández A. Model-based analysis of myocardial contraction patterns in ischemic heart disease. Ing Rech Biomed 2022. [DOI: 10.1016/j.irbm.2022.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5
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Owashi K, Taconné M, Courtial N, Simon A, Garreau M, Hernandez A, Donal E, Le Rolle V, Galli E. Desynchronization Strain Patterns and Contractility in Left Bundle Branch Block through Computer Model Simulation. J Cardiovasc Dev Dis 2022; 9:53. [PMID: 35200706 PMCID: PMC8875371 DOI: 10.3390/jcdd9020053] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/18/2022] [Accepted: 01/25/2022] [Indexed: 01/24/2023] Open
Abstract
Left bundle branch block (LBBB) is associated with specific septal-to-lateral wall activation patterns which are strongly influenced by the intrinsic left ventricular (LV) contractility and myocardial scar localization. The objective of this study was to propose a computational-model-based interpretation of the different patterns of LV contraction observed in the case of LBBB and preserved contractility or myocardial scarring. Two-dimensional transthoracic echocardiography was used to obtain LV volumes and deformation patterns in three patients with LBBB: (1) a patient with non-ischemic dilated cardiomyopathy, (2) a patient with antero-septal myocardial scar, and (3) a patient with lateral myocardial scar. Scar was confirmed by the distribution of late gadolinium enhancement with cardiac magnetic resonance imaging (cMRI). Model parameters were evaluated manually to reproduce patient-derived data such as strain curves obtained from echocardiographic apical views. The model was able to reproduce the specific strain patterns observed in patients. A typical septal flash with pre-ejection shortening, rebound stretch, and delayed lateral wall activation was observed in the case of non-ischemic cardiomyopathy. In the case of lateral scar, the contractility of the lateral wall was significantly impaired and septal flash was absent. In the case of septal scar, septal flash and rebound stretch were also present as previously described in the literature. Interestingly, the model was also able to simulate the specific contractile properties of the myocardium, providing an excellent localization of LV scar in ischemic patients. The model was able to simulate the electromechanical delay and specific contractility patterns observed in patients with LBBB of ischemic and non-ischemic etiology. With further improvement and validation, this technique might be a useful tool for the diagnosis and treatment planning of heart failure patients needing CRT.
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6
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Fan L, Choy JS, Raissi F, Kassab GS, Lee LC. Optimization of cardiac resynchronization therapy based on a cardiac electromechanics-perfusion computational model. Comput Biol Med 2022; 141:105050. [PMID: 34823858 PMCID: PMC8810745 DOI: 10.1016/j.compbiomed.2021.105050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/10/2021] [Accepted: 11/15/2021] [Indexed: 02/03/2023]
Abstract
Cardiac resynchronization therapy (CRT) is an established treatment for left bundle branch block (LBBB) resulting in mechanical dyssynchrony. Approximately 1/3 of patients with CRT, however, are non-responders. To understand factors affecting CRT response, an electromechanics-perfusion computational model based on animal-specific left ventricular (LV) geometry and coronary vascular networks located in the septum and LV free wall is developed. The model considers contractility-flow and preload-activation time relationships, and is calibrated to simultaneously match the experimental measurements in terms of the LV pressure, volume waveforms and total coronary flow in the left anterior descending and left circumflex territories from 2 swine models under right atrium and right ventricular pacing. The model is then applied to investigate the responses of CRT indexed by peak LV pressure and (dP/dt)max at multiple pacing sites with different degrees of perfusion in the LV free wall. Without the presence of ischemia, the model predicts that basal-lateral endocardial region is the optimal pacing site that can best improve (dP/dt)max by 20%, and is associated with the shortest activation time. In the presence of ischemia, a non-ischemic region becomes the optimal pacing site when coronary flow in the ischemic region fell below 30% of its original value. Pacing at the ischemic region produces little response at that perfusion level. The optimal pacing site is associated with one that optimizes the LV activation time. These findings suggest that CRT response is affected by both pacing site and coronary perfusion, which may have clinical implication in improving CRT responder rates.
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Affiliation(s)
- Lei Fan
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
| | - Jenny S Choy
- California Medical Innovations Institute, San Diego, CA, USA
| | - Farshad Raissi
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | | | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA
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7
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Oomen PJA, Phung TKN, Weinberg SH, Bilchick KC, Holmes JW. A rapid electromechanical model to predict reverse remodeling following cardiac resynchronization therapy. Biomech Model Mechanobiol 2022; 21:231-247. [PMID: 34816336 PMCID: PMC9241386 DOI: 10.1007/s10237-021-01532-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 10/22/2021] [Indexed: 10/19/2022]
Abstract
Cardiac resynchronization therapy (CRT) is an effective therapy for patients who suffer from heart failure and ventricular dyssynchrony such as left bundle branch block (LBBB). When it works, it reverses adverse left ventricular (LV) remodeling and the progression of heart failure. However, CRT response rate is currently as low as 50-65%. In theory, CRT outcome could be improved by allowing clinicians to tailor the therapy through patient-specific lead locations, timing, and/or pacing protocol. However, this also presents a dilemma: there are far too many possible strategies to test during the implantation surgery. Computational models could address this dilemma by predicting remodeling outcomes for each patient before the surgery takes place. Therefore, the goal of this study was to develop a rapid computational model to predict reverse LV remodeling following CRT. We adapted our recently developed computational model of LV remodeling to simulate the mechanics of ventricular dyssynchrony and added a rapid electrical model to predict electrical activation timing. The model was calibrated to quantitatively match changes in hemodynamics and global and local LV wall mass from a canine study of LBBB and CRT. The calibrated model was used to investigate the influence of LV lead location and ischemia on CRT remodeling outcome. Our model results suggest that remodeling outcome varies with both lead location and ischemia location, and does not always correlate with short-term improvement in QRS duration. The results and time frame required to customize and run this model suggest promise for this approach in a clinical setting.
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Affiliation(s)
- Pim J. A. Oomen
- Department of Biomedical Engineering, University of Virginia, Box 800759, Health System, Charlottesville, VA 22903, USA
- Department of Medicine, University of Virginia, Box 800158, Health System, Charlottesville, VA 22903, USA
| | - Thien-Khoi N. Phung
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, 665 Huntington Ave, Boston, MA 02115, USA
| | - Seth H. Weinberg
- Department of Biomedical Engineering, The Ohio State University, 140 W 19th Ave Columbus, Columbus, OH 43210, USA
| | - Kenneth C. Bilchick
- Department of Medicine, University of Virginia, Box 800158, Health System, Charlottesville, VA 22903, USA
| | - Jeffrey W. Holmes
- Department of Biomedical Engineering, University of Virginia, Box 800759, Health System, Charlottesville, VA 22903, USA
- School of Engineering, University of Alabama at Birmingham, 1075 13th St S, Birmingham, AL 35233, USA
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8
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Colli Franzone P, Pavarino LF, Scacchi S. Numerical evaluation of cardiac mechanical markers as estimators of the electrical activation time. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3285. [PMID: 31808301 DOI: 10.1002/cnm.3285] [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: 01/17/2019] [Revised: 10/11/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
Recent advances in the development of noninvasive cardiac imaging technologies have made it possible to measure longitudinal and circumferential strains at a high spatial resolution also at intramural level. Local mechanical activation times derived from these strains can be used as noninvasive estimates of electrical activation, in order to determine, eg, the origin of premature ectopic beats during focal arrhythmias or the pathway of reentrant circuits. The aim of this work is to assess the reliability of mechanical activation time markers derived from longitudinal and circumferential strains, denoted by ATell and ATecc , respectively, by means of three-dimensional cardiac electromechanical simulations. These markers are compared against the electrical activation time (ATv ), computed from the action potential waveform, and the reference mechanical activation markers derived from the active tension and fiber strain waveforms, denoted by ATta and ATeff , respectively. Our numerical simulations are based on a strongly coupled electromechanical model, including bidomain representation of the cardiac tissue, mechanoelectric (ie, stretch-activated channels) and geometric feedbacks, transversely isotropic strain energy function for the description of passive mechanics and detailed membrane and excitation-contraction coupling models. The results have shown that, during endocardial and epicardial ectopic stimulations, all the mechanical markers considered are highly correlated with ATv , exhibiting correlation coefficients larger than 0.8. However, during multiple endocardial stimulations, mimicking the ventricular sinus rhythm, the mechanical markers are less correlated with the electrical activation time, because of the more complex resulting excitation sequence. Moreover, the inspection of the endocardial and epicardial isochrones has shown that the ATell and ATecc mechanical activation sequences reproduce only some qualitative features of the electrical activation sequence, such as the areas of early and late activation, but in some cases, they might yield wrong excitation sources and significantly different isochrones patterns.
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Affiliation(s)
| | - Luca F Pavarino
- Dipartimento di Matematica, Università di Milano, Milano, Italy
| | - Simone Scacchi
- Dipartimento di Matematica, Università di Milano, Milano, Italy
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9
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Qauli AI, Marcellinus A, Lim KM. Sensitivity Analysis of Ion Channel Conductance on Myocardial Electromechanical Delay: Computational Study. Front Physiol 2021; 12:697693. [PMID: 34512377 PMCID: PMC8430256 DOI: 10.3389/fphys.2021.697693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 07/29/2021] [Indexed: 02/03/2023] Open
Abstract
It is well known that cardiac electromechanical delay (EMD) can cause dyssynchronous heart failure (DHF), a prominent cardiovascular disease (CVD). This work computationally assesses the conductance variation of every ion channel on the cardiac cell to give rise to EMD prolongation. The electrical and mechanical models of human ventricular tissue were simulated, using a population approach with four conductance reductions for each ion channel. Then, EMD was calculated by determining the difference between the onset of action potential and the start of cell shortening. Finally, EMD data were put into the optimized conductance dimensional stacking to show which ion channel has the most influence in elongating the EMD. We found that major ion channels, such as L-type calcium (CaL), slow-delayed rectifier potassium (Ks), rapid-delayed rectifier potassium (Kr), and inward rectifier potassium (K1), can significantly extend the action potential duration (APD) up to 580 ms. Additionally, the maximum intracellular calcium (Cai) concentration is greatly affected by the reduction in channel CaL, Ks, background calcium, and Kr. However, among the aforementioned major ion channels, only the CaL channel can play a superior role in prolonging the EMD up to 83 ms. Furthermore, ventricular cells with long EMD have been shown to inherit insignificant mechanical response (in terms of how strong the tension can grow and how far length shortening can go) compared with that in normal cells. In conclusion, despite all variations in every ion channel conductance, only the CaL channel can play a significant role in extending EMD. In addition, cardiac cells with long EMD tend to have inferior mechanical responses due to a lack of Cai compared with normal conditions, which are highly likely to result in a compromised pump function of the heart.
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Affiliation(s)
- Ali Ikhsanul Qauli
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, South Korea
| | - Aroli Marcellinus
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, South Korea
| | - Ki Moo Lim
- Department of IT Convergence Engineering, Kumoh National Institute of Technology, Gumi, South Korea
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10
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Dell'Era G, Gravellone M, Scacchi S, Franzone PC, Pavarino LF, Boggio E, Prenna E, De Vecchi F, Occhetta E, Devecchi C, Patti G. A clinical-in silico study on the effectiveness of multipoint bicathodic and cathodic-anodal pacing in cardiac resynchronization therapy. Comput Biol Med 2021; 136:104661. [PMID: 34332350 DOI: 10.1016/j.compbiomed.2021.104661] [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: 04/07/2021] [Revised: 07/16/2021] [Accepted: 07/16/2021] [Indexed: 11/18/2022]
Abstract
Up to one-third of patients undergoing cardiac resynchronization therapy (CRT) are nonresponders. Multipoint bicathodic and cathodic-anodal left ventricle (LV) stimulations could overcome this clinical challenge, but their effectiveness remains controversial. Here we evaluate the performance of such stimulations through both in vivo and in silico experiments, the latter based on computer electromechanical modeling. Seven patients, all candidates for CRT, received a quadripolar LV lead. Four stimulations were tested: right ventricular (RVS); conventional single point biventricular (S-BS); multipoint biventricular bicathodic (CC-BS) and multipoint biventricular cathodic-anodal (CA-BS). The following parameters were processed: QRS duration; maximal time derivative of arterial pressure (dPdtmax); systolic arterial pressure (Psys); and stroke volume (SV). Echocardiographic data of each patient were then obtained to create an LV geometric model. Numerical simulations were based on a strongly coupled Bidomain electromechanical coupling model. Considering the in vivo parameters, when comparing S-BS to RVS, there was no significant decrease in SV (from 45 ± 11 to 44 ± 20 ml) and 6% and 4% increases of dPdtmax and Psys, respectively. Focusing on in silico parameters, with respect to RVS, S-BS exhibited a significant increase of SV, dPdtmax and Psys. Neither the in vivo nor in silico results showed any significant hemodynamic and electrical difference among S-BS, CC-BS and CA-BS configurations. These results show that CC-BS and CA-BS yield a comparable CRT performance, but they do not always yield improvement in terms of hemodynamic parameters with respect to S-BS. The computational results confirmed the in vivo observations, thus providing theoretical support to the clinical experiments.
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Affiliation(s)
- G Dell'Era
- Cardiologia 1, Azienda Ospedaliera Universitaria "Maggiore Della Carità", Novara, Italy
| | - M Gravellone
- Divisione di Cardiologia, Ospedale Degli Infermi, Biella, Italy
| | - S Scacchi
- Dipartimento di Matematica, Università Degli Studi di Milano, Via Saldini 50, 20133, Milano, Italy.
| | - P Colli Franzone
- Dipartimento di Matematica, Università Degli Studi di Pavia, Via Ferrata 1, 27100, Pavia, Italy
| | - L F Pavarino
- Dipartimento di Matematica, Università Degli Studi di Pavia, Via Ferrata 1, 27100, Pavia, Italy
| | - E Boggio
- Divisione di Cardiologia, Ospedale Degli Infermi, Biella, Italy
| | - E Prenna
- Cardiologia 1, Azienda Ospedaliera Universitaria "Maggiore Della Carità", Novara, Italy
| | - F De Vecchi
- Divisione di Cardiologia, Ospedale Sant'Andrea, Vercelli, Italy
| | - E Occhetta
- Divisione di Cardiologia, Ospedale Sant'Andrea, Vercelli, Italy
| | - C Devecchi
- Divisione di Cardiologia, Ospedale Sant'Andrea, Vercelli, Italy
| | - G Patti
- Cardiologia 1, Azienda Ospedaliera Universitaria "Maggiore Della Carità", Novara, Italy; Dipartimento di Medicina Traslazionale, Università Del Piemonte Orientale, Novara, Italy
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11
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Albatat M, Arevalo H, Bergsland J, Strøm V, Balasingham I, Odland HH. Optimal pacing sites in cardiac resynchronization by left ventricular activation front analysis. Comput Biol Med 2020; 128:104159. [PMID: 33301952 DOI: 10.1016/j.compbiomed.2020.104159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/14/2020] [Accepted: 11/29/2020] [Indexed: 10/22/2022]
Abstract
Cardiac resynchronization therapy (CRT) can substantially improve dyssynchronous heart failure and reduce mortality. However, about one-third of patients who are implanted, derive no measurable benefit from CRT. Non-response may partly be due to suboptimal activation of the left ventricle (LV) caused by electrophysiological heterogeneities. The goal of this study is to investigate the performance of a newly developed method used to analyze electrical wavefront propagation in a heart model including myocardial scar and compare this to clinical benchmark studies. We used computational models to measure the maximum activation front (MAF) in the LV during different pacing scenarios. Different heart geometries and scars were created based on cardiac MR images of three patients. The right ventricle (RV) was paced from the apex and the LV was paced from 12 different sites, single site, dual-site and triple site. Our results showed that for single LV site pacing, the pacing site with the largest MAF corresponded with the latest activated regions of the LV demonstrated during RV pacing, which also agrees with previous markers used for predicting optimal single-site pacing location. We then demonstrated the utility of MAF in predicting optimal electrode placements in more complex scenarios including scar and multi-site LV pacing. This study demonstrates the potential value of computational simulations in understanding and planning CRT.
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Affiliation(s)
- Mohammad Albatat
- Intervention Centre, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Hermenegild Arevalo
- Department of Computational Physiology, Simula Research Laboratory, Fornebu, Norway
| | | | - Vilde Strøm
- Department of Computational Physiology, Simula Research Laboratory, Fornebu, Norway
| | - Ilangko Balasingham
- Intervention Centre, Oslo University Hospital, Oslo, Norway; Department of Electronic Systems, Norwegian University of Science and Technology, Trondheim, Norway
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Corrado C, Avezzù A, Lee AWC, Mendoca Costa C, Roney CH, Strocchi M, Bishop M, Niederer SA. Using cardiac ionic cell models to interpret clinical data. WIREs Mech Dis 2020; 13:e1508. [PMID: 33027553 DOI: 10.1002/wsbm.1508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/27/2020] [Accepted: 09/04/2020] [Indexed: 01/24/2023]
Abstract
For over 100 years cardiac electrophysiology has been measured in the clinic. The electrical signals that can be measured span from noninvasive ECG and body surface potentials measurements through to detailed invasive measurements of local tissue electrophysiology. These electrophysiological measurements form a crucial component of patient diagnosis and monitoring; however, it remains challenging to quantitatively link changes in clinical electrophysiology measurements to biophysical cellular function. Multi-scale biophysical computational models represent one solution to this problem. These models provide a formal framework for linking cellular function through to emergent whole organ function and routine clinical diagnostic signals. In this review, we describe recent work on the use of computational models to interpret clinical electrophysiology signals. We review the simulation of human cardiac myocyte electrophysiology in the atria and the ventricles and how these models are being used to link organ scale function to patient disease mechanisms and therapy response in patients receiving implanted defibrillators, \cardiac resynchronisation therapy or suffering from atrial fibrillation and ventricular tachycardia. There is a growing use of multi-scale biophysical models to interpret clinical data. This allows cardiologists to link clinical observations with cellular mechanisms to better understand cardiopathophysiology and identify novel treatment strategies. This article is categorized under: Cardiovascular Diseases > Computational Models Cardiovascular Diseases > Biomedical Engineering Cardiovascular Diseases > Molecular and Cellular Physiology.
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Isotani A, Yoneda K, Iwamura T, Watanabe M, Okada JI, Washio T, Sugiura S, Hisada T, Ando K. Patient-specific heart simulation can identify non-responders to cardiac resynchronization therapy. Heart Vessels 2020; 35:1135-1147. [PMID: 32166443 PMCID: PMC7332486 DOI: 10.1007/s00380-020-01577-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/28/2020] [Indexed: 11/30/2022]
Abstract
To identify non-responders to cardiac resynchronization therapy (CRT), various biomarkers have been proposed, but these attempts have not been successful to date. We tested the clinical applicability of computer simulation of CRT for the identification of non-responders. We used the multi-scale heart simulator “UT-Heart,” which can reproduce the electrophysiology and mechanics of the heart based on a molecular model of the excitation–contraction mechanism. Patient-specific heart models were created for eight heart failure patients who were treated with CRT, based on the clinical data recorded before treatment. Using these heart models, bi-ventricular pacing simulations were performed at multiple pacing sites adopted in clinical practice. Improvement in pumping function measured by the relative change of maximum positive derivative of left ventricular pressure (%ΔdP/dtmax) was compared with the clinical outcome. The operators of the simulation were blinded to the clinical outcome. In six patients, the relative reduction in end-systolic volume exceeded 15% in the follow-up echocardiogram at 3 months (responders) and the remaining two patients were judged as non-responders. The simulated %ΔdP/dtmax at the best lead position could identify responders and non-responders successfully. With further refinement of the model, patient-specific simulation could be a useful tool for identifying non-responders to CRT.
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Affiliation(s)
- Akihiro Isotani
- Department of Cardiovascular Medicine, Kokura Memorial Hospital, Asano 3-2-1, Kokurakita-ku, Kitakyushu, Fukuoka, 802-8555, Japan
| | - Kazunori Yoneda
- Healthcare System Unit, Fujitsu Ltd, Ota-ku, Kamata, 144-8588, Japan
| | - Takashi Iwamura
- Healthcare System Unit, Fujitsu Ltd, Ota-ku, Kamata, 144-8588, Japan
| | - Masahiro Watanabe
- Healthcare System Unit, Fujitsu Ltd, Ota-ku, Kamata, 144-8588, Japan
| | - Jun-Ichi Okada
- Future Center Initiative, The University of Tokyo, Wakashiba 178-4-4, Kashiwa, Chiba, 277-0871, Japan
- UT-Heart Inc. Nozawa, 3-25-8, Setagaya, Tokyo, 154-0003, Japan
| | - Takumi Washio
- Future Center Initiative, The University of Tokyo, Wakashiba 178-4-4, Kashiwa, Chiba, 277-0871, Japan
- UT-Heart Inc. Nozawa, 3-25-8, Setagaya, Tokyo, 154-0003, Japan
| | - Seiryo Sugiura
- UT-Heart Inc. Nozawa, 3-25-8, Setagaya, Tokyo, 154-0003, Japan.
- Future Center #304, Wakashiba 178-4-4, Kashiwa, Chiba, 277-0871, Japan.
| | - Toshiaki Hisada
- UT-Heart Inc. Nozawa, 3-25-8, Setagaya, Tokyo, 154-0003, Japan
| | - Kenji Ando
- Department of Cardiovascular Medicine, Kokura Memorial Hospital, Asano 3-2-1, Kokurakita-ku, Kitakyushu, Fukuoka, 802-8555, Japan
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Comparison of Electromechanical Delay during Ventricular Tachycardia and Fibrillation under Different Conductivity Conditions Using Computational Modeling. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2020; 2020:9501985. [PMID: 32300375 PMCID: PMC7146094 DOI: 10.1155/2020/9501985] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/25/2020] [Indexed: 01/27/2023]
Abstract
Electromechanical delay (EMD) is the time interval between local myocyte depolarization and the onset of myofiber shortening. Previously, researchers measured EMD during sinus rhythm and ectopic pacing in normal and heart failure conditions. However, to our knowledge, there are no reports regarding EMD during another type of rhythms or arrhythmia. The goal of this study was to quantify EMD during sinus rhythm, tachycardia, and ventricular fibrillation conditions. We hypothesized that EMD under sinus rhythm is longer due to isovolumetric contraction which is imprecise during arrhythmia. We used a realistic model of 3D electromechanical ventricles. During sinus rhythm, EMD was measured in the last cycle of cardiac systole under steady conditions. EMD under tachycardia and fibrillation conditions was measured during the entire simulation, resulting in multiple EMD values. We assessed EMD for the following 3 conduction velocities (CVs): 31 cm/s, 51 cm/s, and 69 cm/s. The average EMD during fibrillation condition was the shortest corresponding to 53.45 ms, 55.07 ms, and 50.77 ms, for the CVs of 31 cm/s, 51 cm/s, and 69 cm/s, respectively. The average EMD during tachycardia was 58.61 ms, 58.33 ms, and 52.50 ms for the three CVs. Under sinus rhythm with action potential duration restitution (APDR) slope 0.7, the average EMD was 66.35 ms, 66.41 ms, and 66.60 ms in line with the three CVs. This result supports our hypothesis that EMD under sinus rhythm is longer than that under tachyarrhythmia conditions. In conclusion, this study observed and quantified EMD under tachycardia and ventricular fibrillation conditions. This simulation study has widened our understanding of EMD in 3D ventricles under chaotic conditions.
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Antoniou CK, Manolakou P, Magkas N, Konstantinou K, Chrysohoou C, Dilaveris P, Gatzoulis KA, Tousoulis D. Cardiac Resynchronisation Therapy and Cellular Bioenergetics: Effects Beyond Chamber Mechanics. Eur Cardiol 2019; 14:33-44. [PMID: 31131035 PMCID: PMC6523053 DOI: 10.15420/ecr.2019.2.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cardiac resynchronisation therapy is a cornerstone in the treatment of advanced dyssynchronous heart failure. However, despite its widespread clinical application, precise mechanisms through which it exerts its beneficial effects remain elusive. Several studies have pointed to a metabolic component suggesting that, both in concert with alterations in chamber mechanics and independently of them, resynchronisation reverses detrimental changes to cellular metabolism, increasing energy efficiency and metabolic reserve. These actions could partially account for the existence of responders that improve functionally but not echocardiographically. This article will attempt to summarise key components of cardiomyocyte metabolism in health and heart failure, with a focus on the dyssynchronous variant. Both chamber mechanics-related and -unrelated pathways of resynchronisation effects on bioenergetics – stemming from the ultramicroscopic level – and a possible common underlying mechanism relating mechanosensing to metabolism through the cytoskeleton will be presented. Improved insights regarding the cellular and molecular effects of resynchronisation on bioenergetics will promote our understanding of non-response, optimal device programming and lead to better patient care.
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Affiliation(s)
| | - Panagiota Manolakou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Nikolaos Magkas
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Konstantinos Konstantinou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Christina Chrysohoou
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Polychronis Dilaveris
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Konstantinos A Gatzoulis
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
| | - Dimitrios Tousoulis
- First Department of Cardiology, School of Medicine, National and Kapodistrian University of Athens Athens, Greece
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16
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Abstract
The treatment of individual patients in cardiology practice increasingly relies on advanced imaging, genetic screening and devices. As the amount of imaging and other diagnostic data increases, paralleled by the greater capacity to personalize treatment, the difficulty of using the full array of measurements of a patient to determine an optimal treatment seems also to be paradoxically increasing. Computational models are progressively addressing this issue by providing a common framework for integrating multiple data sets from individual patients. These models, which are based on physiology and physics rather than on population statistics, enable computational simulations to reveal diagnostic information that would have otherwise remained concealed and to predict treatment outcomes for individual patients. The inherent need for patient-specific models in cardiology is clear and is driving the rapid development of tools and techniques for creating personalized methods to guide pharmaceutical therapy, deployment of devices and surgical interventions.
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Affiliation(s)
- Steven A Niederer
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.
| | - Joost Lumens
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, Netherlands
- IHU LIRYC, Electrophysiology and Heart Modeling Institute, Fondation Bordeaux Université, Pessac, France
| | - Natalia A Trayanova
- Department of Biomedical Engineering and the Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD, USA
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Albatat M, King DR, Unger LA, Arevalo H, Wall S, Sundnes J, Bergsland J, Balasingham I. Electromechanical Model to Predict Cardiac Resynchronization Therapy. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:5446-5459. [PMID: 30441569 DOI: 10.1109/embc.2018.8513539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cardiac resynchronization therapy (CRT) can substantially improve dyssynchronous heart failure and reduce mortality. However, one-third of the CRT patients derive no measurable benefit from CRT, due to suboptimal placement of the left ventricular (LV) lead. We introduce a pipeline for improved CRT-therapy by creating an electromechanical model using patient-specific geometric parameters allowing individualization of therapy. The model successfully mimics expected changes when variables for tension, stiffness, and conduction are entered. Changing LV pacing site had a notable effect on maximum pressure gradient (dP/dtmax) in the presence of cardiac scarring, causing non-uniform excitation propagation through the LV. Tailoring CRT to the individual requires simulations with patient-specific biventricular meshes including cardiac geometry and conductivity properties.
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18
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Aghasafari P, George U, Pidaparti R. A review of inflammatory mechanism in airway diseases. Inflamm Res 2018; 68:59-74. [PMID: 30306206 DOI: 10.1007/s00011-018-1191-2] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 09/12/2018] [Accepted: 09/27/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Inflammation in the lung is the body's natural response to injury. It acts to remove harmful stimuli such as pathogens, irritants, and damaged cells and initiate the healing process. Acute and chronic pulmonary inflammation are seen in different respiratory diseases such as; acute respiratory distress syndrome, chronic obstructive pulmonary disease (COPD), asthma, and cystic fibrosis (CF). FINDINGS In this review, we found that inflammatory response in COPD is determined by the activation of epithelial cells and macrophages in the respiratory tract. Epithelial cells and macrophages discharge transforming growth factor-β (TGF-β), which trigger fibroblast proliferation and tissue remodeling. Asthma leads to airway hyper-responsiveness, obstruction, mucus hyper-production, and airway-wall remodeling. Cytokines, allergens, chemokines, and infectious agents are the main stimuli that activate signaling pathways in epithelial cells in asthma. Mutation of the CF transmembrane conductance regulator (CFTR) gene results in CF. Mutations in CFTR influence the lung epithelial innate immune function that leads to exaggerated and ineffective airway inflammation that fails to abolish pulmonary pathogens. We present mechanistic computational models (based on ordinary differential equations, partial differential equations and agent-based models) that have been applied in studying the complex physiological and pathological mechanisms of chronic inflammation in different airway diseases. CONCLUSION The scope of the present review is to explore the inflammatory mechanism in airway diseases and highlight the influence of aging on airways' inflammation mechanism. The main goal of this review is to encourage research collaborations between experimentalist and modelers to promote our understanding of the physiological and pathological mechanisms that control inflammation in different airway diseases.
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Affiliation(s)
| | - Uduak George
- College of Engineering, University of Georgia, Athens, GA, USA.,Department of Mathematics and Statistics, San Diego State University, San Diego, CA, USA
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19
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Shavik SM, Wall ST, Sundnes J, Burkhoff D, Lee LC. Organ-level validation of a cross-bridge cycling descriptor in a left ventricular finite element model: effects of ventricular loading on myocardial strains. Physiol Rep 2018; 5:5/21/e13392. [PMID: 29122952 PMCID: PMC5688770 DOI: 10.14814/phy2.13392] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 07/23/2017] [Indexed: 12/22/2022] Open
Abstract
Although detailed cell‐based descriptors of cross‐bridge cycling have been applied in finite element (FE) heart models to describe ventricular mechanics, these multiscale models have never been tested rigorously to determine if these descriptors, when scaled up to the organ‐level, are able to reproduce well‐established organ‐level physiological behaviors. To address this void, we here validate a left ventricular (LV) FE model that is driven by a cell‐based cross‐bridge cycling descriptor against key organ‐level heart physiology. The LV FE model was coupled to a closed‐loop lumped parameter circulatory model to simulate different ventricular loading conditions (preload and afterload) and contractilities. We show that our model is able to reproduce a linear end‐systolic pressure volume relationship, a curvilinear end‐diastolic pressure volume relationship and a linear relationship between myocardial oxygen consumption and pressure–volume area. We also show that the validated model can predict realistic LV strain‐time profiles in the longitudinal, circumferential, and radial directions. The predicted strain‐time profiles display key features that are consistent with those measured in humans, such as having similar peak strains, time‐to‐peak‐strain, and a rapid change in strain during atrial contraction at late‐diastole. Our model shows that the myocardial strains are sensitive to not only LV contractility, but also to the LV loading conditions, especially to a change in afterload. This result suggests that caution must be exercised when associating changes in myocardial strain with changes in LV contractility. The methodically validated multiscale model will be used in future studies to understand human heart diseases.
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Affiliation(s)
| | | | | | - Daniel Burkhoff
- Cardiovascular Research Foundation and Department of Medicine, Columbia University, New York, New York
| | - Lik Chuan Lee
- Department of Mechanical Engineering, Michigan State University, East Lansing, Michigan
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20
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Colli Franzone P, Pavarino LF, Scacchi S. A Numerical Study of Scalable Cardiac Electro-Mechanical Solvers on HPC Architectures. Front Physiol 2018; 9:268. [PMID: 29674971 PMCID: PMC5895745 DOI: 10.3389/fphys.2018.00268] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/08/2018] [Indexed: 11/13/2022] Open
Abstract
We introduce and study some scalable domain decomposition preconditioners for cardiac electro-mechanical 3D simulations on parallel HPC (High Performance Computing) architectures. The electro-mechanical model of the cardiac tissue is composed of four coupled sub-models: (1) the static finite elasticity equations for the transversely isotropic deformation of the cardiac tissue; (2) the active tension model describing the dynamics of the intracellular calcium, cross-bridge binding and myofilament tension; (3) the anisotropic Bidomain model describing the evolution of the intra- and extra-cellular potentials in the deforming cardiac tissue; and (4) the ionic membrane model describing the dynamics of ionic currents, gating variables, ionic concentrations and stretch-activated channels. This strongly coupled electro-mechanical model is discretized in time with a splitting semi-implicit technique and in space with isoparametric finite elements. The resulting scalable parallel solver is based on Multilevel Additive Schwarz preconditioners for the solution of the Bidomain system and on BDDC preconditioned Newton-Krylov solvers for the non-linear finite elasticity system. The results of several 3D parallel simulations show the scalability of both linear and non-linear solvers and their application to the study of both physiological excitation-contraction cardiac dynamics and re-entrant waves in the presence of different mechano-electrical feedbacks.
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Affiliation(s)
| | - Luca F Pavarino
- Department of Mathematics, University of Pavia, Pavia, Italy
| | - Simone Scacchi
- Department of Mathematics, University of Milano, Milan, Italy
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21
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Lee AWC, Costa CM, Strocchi M, Rinaldi CA, Niederer SA. Computational Modeling for Cardiac Resynchronization Therapy. J Cardiovasc Transl Res 2018; 11:92-108. [PMID: 29327314 PMCID: PMC5908824 DOI: 10.1007/s12265-017-9779-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/18/2017] [Indexed: 11/21/2022]
Abstract
Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure (HF) patients with an electrical substrate pathology causing ventricular dyssynchrony. However 40-50% of patients do not respond to treatment. Cardiac modeling of the electrophysiology, electromechanics, and hemodynamics of the heart has been used to study mechanisms behind HF pathology and CRT response. Recently, multi-scale dyssynchronous HF models have been used to study optimal device settings and optimal lead locations, investigate the underlying cardiac pathophysiology, as well as investigate emerging technologies proposed to treat cardiac dyssynchrony. However the breadth of patient and experimental data required to create and parameterize these models and the computational resources required currently limits the use of these models to small patient numbers. In the future, once these technical challenges are overcome, biophysically based models of the heart have the potential to become a clinical tool to aid in the diagnosis and treatment of HF.
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Affiliation(s)
- Angela W C Lee
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK.
| | | | - Marina Strocchi
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | | | - Steven A Niederer
- School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
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22
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Huntjens PR, Ploux S, Strik M, Walmsley J, Ritter P, Haissaguerre M, Prinzen FW, Delhaas T, Lumens J, Bordachar P. Electrical Substrates Driving Response to Cardiac Resynchronization Therapy. Circ Arrhythm Electrophysiol 2018; 11:e005647. [DOI: 10.1161/circep.117.005647] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 01/22/2018] [Indexed: 11/16/2022]
Affiliation(s)
- Peter R. Huntjens
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - Sylvain Ploux
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - Marc Strik
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - John Walmsley
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - Philippe Ritter
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - Michel Haissaguerre
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - Frits W. Prinzen
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - Tammo Delhaas
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - Joost Lumens
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
| | - Pierre Bordachar
- Electrophysiology and Heart Modeling Institute (LIRYC), Bordeaux University, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiac Electrophysiology and Cardiac Stimulation Team, Bordeaux University Hospital, Pessac, France (P.R.H., S.P., M.S., P.R., M.H., J.L., P.B.). Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, the Netherlands (P.R.H., M.S., J.W., F.W.P., T.D., J.L.)
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23
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Porta-Sánchez A, Angaran P, Massé S, Nair K, Farid T, Umapathy K, Asta J, Gizurarson S, Nanthakumar K. The effect of left ventricular pacing on transmural activation delay in myopathic human hearts. Europace 2018; 20:719-728. [PMID: 28108548 DOI: 10.1093/europace/euw375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 10/22/2016] [Indexed: 11/13/2022] Open
Abstract
Aims Left ventricular (LV) epicardial pacing (LVEpiP) in human myopathic hearts does not decrease global epicardial activation delay compared with right ventricular (RV) endocardial pacing (RVEndoP); however, the effect on transmural activation delay has not been evaluated. To characterize the transmural electrical activation delay in human myopathic hearts during RVEndoP and LVEpiP compared with global epicardial activation delay. Methods and results Explanted hearts from seven patients (5 male, 46 ± 10 years) undergoing cardiac transplantation were Langendorff-perfused and mapped using an epicardial sock electrode array (112 electrodes) and 25 transmural plunge needles (four electrodes, 2 mm spacing), for a total of 100 unipolar transmural electrodes. Electrograms were recorded during LVEpiP and RVEndoP, and epicardial (sock) and transmural (needle) activation times, along with patterns of activation, were compared. There was no difference between the global epicardial activation times (LVEpiP 147 ± 8 ms vs. RVEndoP 156 ± 17 ms, P = 0.46). The mean LV transmural activation time during LVEpiP was significantly shorter than that during RVEndoP (125 ± 44 vs. 172 ± 43 ms, P < 0.001). During LVEpiP, of the transmural layers endo-, mid-myocardium and epicardium, LV endocardial layer was often the earliest compared with other transmural layers. Conclusion In myopathic human hearts, LVEpiP did not decrease global epicardial activation delays compared with RVEndoP. LV epicardial pacing led to early activation of the LV endocardium, revealing the importance of the LV endocardium even when pacing from the LV epicardium.
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Affiliation(s)
- Andreu Porta-Sánchez
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
| | - Paul Angaran
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
| | - Stéphane Massé
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
| | - Krishnakumar Nair
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
| | - Talha Farid
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
| | - Karthikeyan Umapathy
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
| | - John Asta
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
| | - Sigfus Gizurarson
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
| | - Kumaraswamy Nanthakumar
- The Hull Family Cardiac Fibrillation Management Laboratory, University Health Network, Toronto General Hospital, 150 Gerrard Street West, Gerrard Wing, 3-526, Toronto, ON, Canada M5G 2C4
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Influence of LVAD function on mechanical unloading and electromechanical delay: a simulation study. Med Biol Eng Comput 2017; 56:911-921. [PMID: 29098548 PMCID: PMC5906510 DOI: 10.1007/s11517-017-1730-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 10/04/2017] [Indexed: 12/16/2022]
Abstract
This study hypothesized that a left ventricular assist device (LVAD) shortens the electromechanical delay (EMD) by mechanical unloading. The goal of this study is to examine, by computational modeling, the influence of LVAD on EMD for four heart failure (HF) cases ranging from mild HF to severe HF. We constructed an integrated model of an LVAD-implanted cardiovascular system, then we altered the Ca2+ transient magnitude, with scaling factors 1, 0.9, 0.8, and 0.7 representing HF1, HF2, HF3, and HF4, respectively, in order of increasing HF severity. The four HF conditions are classified into two groups. Group one is the four HF conditions without LVAD, and group two is the conditions treated with continuous LVAD pump. The single-cell mechanical responses showed that EMD was prolonged with the higher load. The findings indicated that in group one, the HF-induced Ca2 + transient remodeling prolonged the mechanical activation time (MAT) and decreased the contractile tension, which reduced the left ventricle (LV) pressure, and increased the end-diastolic strain. In group two, LVAD shortened MAT of the ventricles. Furthermore, LVAD reduced the contractile tension, and end-diastolic strain, but increased the aortic pressure. The computational study demonstrated that LVAD shortens EMD by mechanical unloading of the ventricle.
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Garcia-Canadilla P, Rodriguez JF, Palazzi MJ, Gonzalez-Tendero A, Schönleitner P, Balicevic V, Loncaric S, Luiken JJFP, Ceresa M, Camara O, Antoons G, Crispi F, Gratacos E, Bijnens B. A two dimensional electromechanical model of a cardiomyocyte to assess intra-cellular regional mechanical heterogeneities. PLoS One 2017; 12:e0182915. [PMID: 28837585 PMCID: PMC5570434 DOI: 10.1371/journal.pone.0182915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 07/26/2017] [Indexed: 01/01/2023] Open
Abstract
Experimental studies on isolated cardiomyocytes from different animal species and human hearts have demonstrated that there are regional differences in the Ca2+ release, Ca2+ decay and sarcomere deformation. Local deformation heterogeneities can occur due to a combination of factors: regional/local differences in Ca2+ release and/or re-uptake, intra-cellular material properties, sarcomere proteins and distribution of the intracellular organelles. To investigate the possible causes of these heterogeneities, we developed a two-dimensional finite-element electromechanical model of a cardiomyocyte that takes into account the experimentally measured local deformation and cytosolic [Ca2+] to locally define the different variables of the constitutive equations describing the electro/mechanical behaviour of the cell. Then, the model was individualised to three different rat cardiac cells. The local [Ca2+] transients were used to define the [Ca2+]-dependent activation functions. The cell-specific local Young's moduli were estimated by solving an inverse problem, minimizing the error between the measured and simulated local deformations along the longitudinal axis of the cell. We found that heterogeneities in the deformation during contraction were determined mainly by the local elasticity rather than the local amount of Ca2+, while in the relaxation phase deformation was mainly influenced by Ca2+ re-uptake. Our electromechanical model was able to successfully estimate the local elasticity along the longitudinal direction in three different cells. In conclusion, our proposed model seems to be a good approximation to assess the heterogeneous intracellular mechanical properties to help in the understanding of the underlying mechanisms of cardiomyocyte dysfunction.
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Affiliation(s)
| | - Jose F. Rodriguez
- LaBS, Chemistry, materials and chemical engineering department “Giulio Natta”, Politecnico di Milano, Milano, Italy
| | - Maria J. Palazzi
- Dept. of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Anna Gonzalez-Tendero
- BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), Fetal i+D Fetal Medicine Research Center, IDIBAPS, University of Barcelona, Barcelona, Spain
| | | | - Vedrana Balicevic
- Faculty of Electrical Engineering and Computing, University of Zagreb, Zagreb, Croatia
| | - Sven Loncaric
- Molecular Genetics, Maastricht University, Maastricht, The Netherlands
| | | | - Mario Ceresa
- Dept. of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Oscar Camara
- Dept. of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
| | - Gudrun Antoons
- Dept. of Physiology, Maastricht University, Maastricht, The Netherlands
| | - Fatima Crispi
- BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), Fetal i+D Fetal Medicine Research Center, IDIBAPS, University of Barcelona, Barcelona, Spain
- Centre for Biomedical Research on Rare Diseases (CIBER-ER), Madrid, Spain
| | - Eduard Gratacos
- BCNatal - Barcelona Center for Maternal-Fetal and Neonatal Medicine (Hospital Clínic and Hospital Sant Joan de Deu), Fetal i+D Fetal Medicine Research Center, IDIBAPS, University of Barcelona, Barcelona, Spain
- Centre for Biomedical Research on Rare Diseases (CIBER-ER), Madrid, Spain
| | - Bart Bijnens
- Dept. of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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Colli Franzone P, Pavarino LF, Scacchi S. Joint influence of transmural heterogeneities and wall deformation on cardiac bioelectrical activity: A simulation study. Math Biosci 2016; 280:71-86. [PMID: 27545966 DOI: 10.1016/j.mbs.2016.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/25/2016] [Accepted: 08/04/2016] [Indexed: 10/21/2022]
Abstract
The aim of this work is to investigate, by means of numerical simulations, the influence of myocardial deformation due to muscle contraction and relaxation on the cardiac repolarization process in presence of transmural intrinsic action potential duration (APD) heterogeneities. The three-dimensional electromechanical model considered consists of the following four coupled components: the quasi-static transversely isotropic finite elasticity equations for the deformation of the cardiac tissue; the active tension model for the intracellular calcium dynamics and cross-bridge binding; the anisotropic Bidomain model for the electrical current flow through the deforming cardiac tissue; the membrane model of ventricular myocytes, including stretch-activated channels. The numerical simulations are based on our finite element parallel solver, which employs Multilevel Additive Schwarz preconditioners for the solution of the discretized Bidomain equations and Newton-Krylov methods for the solution of the discretized non-linear finite elasticity equations. Our findings show that: (i) the presence of intrinsic transmural cellular APD heterogeneities is not fully masked by electrotonic current flow or by the presence of the mechanical deformation; (ii) despite the presence of transmural APD heterogeneities, the recovery process follows the activation sequence and there is no significant transmural repolarization gradient; (iii) with or without transmural APD heterogeneities, epicardial electrograms always display the same wave shape and discordance between the polarity of QRS complex and T-wave; (iv) the main effects of the mechanical deformation are an increase of the dispersion of repolarization time and APD, when computed over the total cardiac domain and over the endo- and epicardial surfaces, while there is a slight decrease along the transmural direction.
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Affiliation(s)
- P Colli Franzone
- Dipartimento di Matematica, Università di Pavia, Via Ferrata 1, Pavia 27100, Italy.
| | - L F Pavarino
- Dipartimento di Matematica, Università di Milano, Via Saldini 50, Milano 20133, Italy.
| | - S Scacchi
- Dipartimento di Matematica, Università di Milano, Via Saldini 50, Milano 20133, Italy.
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Panthee N, Okada JI, Washio T, Mochizuki Y, Suzuki R, Koyama H, Ono M, Hisada T, Sugiura S. Tailor-made heart simulation predicts the effect of cardiac resynchronization therapy in a canine model of heart failure. Med Image Anal 2016; 31:46-62. [PMID: 26973218 DOI: 10.1016/j.media.2016.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 02/12/2016] [Accepted: 02/15/2016] [Indexed: 11/25/2022]
Abstract
Despite extensive studies on clinical indices for the selection of patient candidates for cardiac resynchronization therapy (CRT), approximately 30% of selected patients do not respond to this therapy. Herein, we examined whether CRT simulations based on individualized realistic three-dimensional heart models can predict the therapeutic effect of CRT in a canine model of heart failure with left bundle branch block. In four canine models of failing heart with dyssynchrony, individualized three-dimensional heart models reproducing the electromechanical activity of each animal were created based on the computer tomographic images. CRT simulations were performed for 25 patterns of three ventricular pacing lead positions. Lead positions producing the best and the worst therapeutic effects were selected in each model. The validity of predictions was tested in acute experiments in which hearts were paced from the sites identified by simulations. We found significant correlations between the experimentally observed improvement in ejection fraction (EF) and the predicted improvements in ejection fraction (P<0.01) or the maximum value of the derivative of left ventricular pressure (P<0.01). The optimal lead positions produced better outcomes compared with the worst positioning in all dogs studied, although there were significant variations in responses. Variations in ventricular wall thickness among the dogs may have contributed to these responses. Thus CRT simulations using the individualized three-dimensional heart models can predict acute hemodynamic improvement, and help determine the optimal positions of the pacing lead.
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Affiliation(s)
- Nirmal Panthee
- Department of Cardiac Surgery, School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 Japan
| | - Jun-ichi Okada
- Department of Human and Engineered Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871 Japan; UT-Heart Inc. 3-25-8 Nozawa, Setagaya-ku, Tokyo 154-0003 Japan
| | - Takumi Washio
- Department of Human and Engineered Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871 Japan; UT-Heart Inc. 3-25-8 Nozawa, Setagaya-ku, Tokyo 154-0003 Japan
| | - Youhei Mochizuki
- Laboratory of Veterinary Internal Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino-shi, Tokyo 180-8602 Japan
| | - Ryohei Suzuki
- Laboratory of Veterinary Internal Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino-shi, Tokyo 180-8602 Japan
| | - Hidekazu Koyama
- Laboratory of Veterinary Internal Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonancho, Musashino-shi, Tokyo 180-8602 Japan
| | - Minoru Ono
- Department of Cardiac Surgery, School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 Japan
| | - Toshiaki Hisada
- Department of Human and Engineered Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871 Japan; UT-Heart Inc. 3-25-8 Nozawa, Setagaya-ku, Tokyo 154-0003 Japan
| | - Seiryo Sugiura
- Department of Human and Engineered Environmental Studies, Graduate School of Frontier Sciences, The University of Tokyo, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871 Japan; UT-Heart Inc. 3-25-8 Nozawa, Setagaya-ku, Tokyo 154-0003 Japan.
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Gomez JF, Cardona K, Trenor B. Lessons learned from multi-scale modeling of the failing heart. J Mol Cell Cardiol 2015; 89:146-59. [PMID: 26476237 DOI: 10.1016/j.yjmcc.2015.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/07/2015] [Accepted: 10/14/2015] [Indexed: 12/26/2022]
Abstract
Heart failure constitutes a major public health problem worldwide. Affected patients experience a number of changes in the electrical function of the heart that predispose to potentially lethal cardiac arrhythmias. Due to the multitude of electrophysiological changes that may occur during heart failure, the scientific literature is complex and sometimes ambiguous, perhaps because these findings are highly dependent on the etiology, the stage of heart failure, and the experimental model used to study these changes. Nevertheless, a number of common features of failing hearts have been documented. Prolongation of the action potential (AP) involving ion channel remodeling and alterations in calcium handling have been established as the hallmark characteristics of myocytes isolated from failing hearts. Intercellular uncoupling and fibrosis are identified as major arrhythmogenic factors. Multi-scale computational simulations are a powerful tool that complements experimental and clinical research. The development of biophysically detailed computer models of single myocytes and cardiac tissues has contributed greatly to our understanding of processes underlying excitation and repolarization in the heart. The electrical, structural, and metabolic remodeling that arises in cardiac tissues during heart failure has been addressed from different computational perspectives to further understand the arrhythmogenic substrate. This review summarizes the contributions from computational modeling and simulation to predict the underlying mechanisms of heart failure phenotypes and their implications for arrhythmogenesis, ranging from the cellular level to whole-heart simulations. The main aspects of heart failure are presented in several related sections. An overview of the main electrophysiological and structural changes that have been observed experimentally in failing hearts is followed by the description and discussion of the simulation work in this field at the cellular level, and then in 2D and 3D cardiac structures. The implications for arrhythmogenesis in heart failure are also discussed including therapeutic measures, such as drug effects and cardiac resynchronization therapy. Finally, the future challenges in heart failure modeling and simulation will be discussed.
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Affiliation(s)
- Juan F Gomez
- Instituto de Investigación Interuniversitario en Bioingeniería y Tecnología Orientada, al Ser Humano (I3BH), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
| | - Karen Cardona
- Instituto de Investigación Interuniversitario en Bioingeniería y Tecnología Orientada, al Ser Humano (I3BH), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
| | - Beatriz Trenor
- Instituto de Investigación Interuniversitario en Bioingeniería y Tecnología Orientada, al Ser Humano (I3BH), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain.
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Choi YJ, Constantino J, Vedula V, Trayanova N, Mittal R. A New MRI-Based Model of Heart Function with Coupled Hemodynamics and Application to Normal and Diseased Canine Left Ventricles. Front Bioeng Biotechnol 2015; 3:140. [PMID: 26442254 PMCID: PMC4585083 DOI: 10.3389/fbioe.2015.00140] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 08/31/2015] [Indexed: 11/22/2022] Open
Abstract
A methodology for the simulation of heart function that combines an MRI-based model of cardiac electromechanics (CE) with a Navier–Stokes-based hemodynamics model is presented. The CE model consists of two coupled components that simulate the electrical and the mechanical functions of the heart. Accurate representations of ventricular geometry and fiber orientations are constructed from the structural magnetic resonance and the diffusion tensor MR images, respectively. The deformation of the ventricle obtained from the electromechanical model serves as input to the hemodynamics model in this one-way coupled approach via imposed kinematic wall velocity boundary conditions and at the same time, governs the blood flow into and out of the ventricular volume. The time-dependent endocardial surfaces are registered using a diffeomorphic mapping algorithm, while the intraventricular blood flow patterns are simulated using a sharp-interface immersed boundary method-based flow solver. The utility of the combined heart-function model is demonstrated by comparing the hemodynamic characteristics of a normal canine heart beating in sinus rhythm against that of the dyssynchronously beating failing heart. We also discuss the potential of coupled CE and hemodynamics models for various clinical applications.
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Affiliation(s)
- Young Joon Choi
- Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA ; Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA
| | - Jason Constantino
- Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA ; Department of Biomedical Engineering, Johns Hopkins University , Baltimore, MD , USA
| | - Vijay Vedula
- Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA
| | - Natalia Trayanova
- Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA ; Department of Biomedical Engineering, Johns Hopkins University , Baltimore, MD , USA
| | - Rajat Mittal
- Department of Mechanical Engineering, Johns Hopkins University , Baltimore, MD , USA ; Institute for Computational Medicine, Johns Hopkins University , Baltimore, MD , USA
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Potse M, Krause D, Kroon W, Murzilli R, Muzzarelli S, Regoli F, Caiani E, Prinzen FW, Krause R, Auricchio A. Patient-specific modelling of cardiac electrophysiology in heart-failure patients. Europace 2015; 16 Suppl 4:iv56-iv61. [PMID: 25362171 PMCID: PMC4217520 DOI: 10.1093/europace/euu257] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Aims Left-ventricular (LV) conduction disturbances are common in heart-failure patients and a left bundle-branch block (LBBB) electrocardiogram (ECG) type is often seen. The precise cause of this pattern is uncertain and is probably variable between patients, ranging from proximal interruption of the left bundle branch to diffuse distal conduction disease in the working myocardium. Using realistic numerical simulation methods and patient-tailored model anatomies, we investigated different hypotheses to explain the observed activation order on the LV endocardium, electrogram morphologies, and ECG features in two patients with heart failure and LBBB ECG. Methods and results Ventricular electrical activity was simulated using reaction–diffusion models with patient-specific anatomies. From the simulated action potentials, ECGs and cardiac electrograms were computed by solving the bidomain equation. Model parameters such as earliest activation sites, tissue conductivity, and densities of ionic currents were tuned to reproduce the measured signals. Electrocardiogram morphology and activation order could be matched simultaneously. Local electrograms matched well at some sites, but overall the measured waveforms had deeper S-waves than the simulated waveforms. Conclusion Tuning a reaction–diffusion model of the human heart to reproduce measured ECGs and electrograms is feasible and may provide insights in individual disease characteristics that cannot be obtained by other means.
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Affiliation(s)
- Mark Potse
- Center for Computational Medicine in Cardiology, Faculty of Informatics, Università della Svizzera italiana, Via Giuseppe Buffi 13, 6904 Lugano, Switzerland Inria Bordeaux Sud-Ouest, 33405 Talence CEDEX, France
| | - Dorian Krause
- Institute of Computational Science, Faculty of Informatics, Università della Svizzera italiana, 6904 Lugano, Switzerland
| | - Wilco Kroon
- Institute of Computational Science, Faculty of Informatics, Università della Svizzera italiana, 6904 Lugano, Switzerland
| | - Romina Murzilli
- Division of Cardiology, Fondazione Cardiocentro Ticino, 6904 Lugano, Switzerland
| | - Stefano Muzzarelli
- Division of Cardiology, Fondazione Cardiocentro Ticino, 6904 Lugano, Switzerland
| | - François Regoli
- Division of Cardiology, Fondazione Cardiocentro Ticino, 6904 Lugano, Switzerland
| | - Enrico Caiani
- Department of Electronics, Information, and Bioengineering, Politecnico di Milano, 20133 Milano, Italy
| | - Frits W Prinzen
- Center for Computational Medicine in Cardiology, Faculty of Informatics, Università della Svizzera italiana, Via Giuseppe Buffi 13, 6904 Lugano, Switzerland Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Rolf Krause
- Center for Computational Medicine in Cardiology, Faculty of Informatics, Università della Svizzera italiana, Via Giuseppe Buffi 13, 6904 Lugano, Switzerland Institute of Computational Science, Faculty of Informatics, Università della Svizzera italiana, 6904 Lugano, Switzerland
| | - Angelo Auricchio
- Center for Computational Medicine in Cardiology, Faculty of Informatics, Università della Svizzera italiana, Via Giuseppe Buffi 13, 6904 Lugano, Switzerland Division of Cardiology, Fondazione Cardiocentro Ticino, 6904 Lugano, Switzerland
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Huntjens PR, Walmsley J, Ploux S, Bordachar P, Prinzen FW, Delhaas T, Lumens J. Influence of left ventricular lead position relative to scar location on response to cardiac resynchronization therapy: a model study. Europace 2014; 16 Suppl 4:iv62-iv68. [DOI: 10.1093/europace/euu231] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Glass L, Shrier A. Functional Characterization of Oscillatory and Excitable Media. Bull Math Biol 2014; 77:782-95. [DOI: 10.1007/s11538-014-0015-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 08/20/2014] [Indexed: 11/30/2022]
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Hu Y, Gurev V, Constantino J, Trayanova N. Optimizing cardiac resynchronization therapy to minimize ATP consumption heterogeneity throughout the left ventricle: a simulation analysis using a canine heart failure model. Heart Rhythm 2014; 11:1063-9. [PMID: 24657430 PMCID: PMC4049272 DOI: 10.1016/j.hrthm.2014.03.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Indexed: 12/29/2022]
Abstract
BACKGROUND Cardiac resynchronization therapy (CRT) has been demonstrated to lead to restoration of oxygen consumption homogeneity throughout the left ventricle (LV), which is important for long-term reverse remodeling of the ventricles. However, research has focused exclusively on identifying the LV pacing sites that led to acute hemodynamic improvements. It remains unclear whether there exist LV pacing sites that could both improve the hemodynamics and result in ATP consumption homogeneity throughout the LV, thus maximizing both CRT short-term and long-term benefits. OBJECTIVE The purpose of this study was to demonstrate the feasibility of optimizing CRT pacing locations to achieve maximal improvement in both ATPCTHI (an ATP consumption heterogeneity index) and stroke work. METHODS We used an magnetic resonance image-based electromechanical model of the dyssynchronous heart failure (DHF) canine ventricles. ATPCTHI and stroke work improvement were determined for each of 34 CRT pacing sites evenly spaced over the LV epicardium. RESULTS Results demonstrated the feasibility of determining the optimal LV pacing site that achieves simultaneous maximum improvements in ATPCTHI and stroke work. The optimal LV CRT pacing sites in the DHF canine ventricles were located midway between apex and base. The improvement in ATPCTHI decreased more rapidly with the distance from the optimal sites compared to stroke work improvement. CRT from the optimal sites homogenized ATP consumption by increasing septal ATP consumption and decreasing that of the lateral wall. CONCLUSION Simulation results using a canine heart failure model demonstrated that CRT can be optimized to achieve improvements in both ATPCTHI and stroke work.
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Affiliation(s)
- Yuxuan Hu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Viatcheslav Gurev
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Jason Constantino
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Natalia Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland.
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Suever JD, Hartlage GR, Magrath III RP, Iravanian S, Lloyd MS, Oshinski JN. Relationship between mechanical dyssynchrony and intra-operative electrical delay times in patients undergoing cardiac resynchronization therapy. J Cardiovasc Magn Reson 2014; 16:4. [PMID: 24393383 PMCID: PMC3895745 DOI: 10.1186/1532-429x-16-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 12/27/2013] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND It is important to understand the relationship between electrical and mechanical ventricular activation in CRT patients. By measuring local electrical activation at multiple locations within the coronary veins and myocardial contraction at the same locations in the left ventricle, we determined the relationship between electrical and mechanical activation at potential left ventricular pacing locations. METHODS In this study, mechanical contraction times were computed using high temporal resolution cine cardiovascular magnetic resonance (CMR) data, while electrical activation times were derived from intra-procedural local electrograms. RESULTS In our cohort, there was a strong correlation between electrical and mechanical delay times within each patient (R2=0.78 ± 0.23). Additionally, the latest electrically activated location corresponded with the latest mechanically contracting location in 91% of patients. CONCLUSIONS This study provides initial evidence that our method of obtaining non-invasive mechanical activation patterns accurately reflects the underlying electromechanical substrate of intraventricular dyssynchrony.
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Affiliation(s)
- Jonathan D Suever
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology / Emory University, 1364 Clifton Road, Suite AG30, Atlanta, GA 30322, USA
| | - Gregory R Hartlage
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - R Patrick Magrath III
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology / Emory University, 1364 Clifton Road, Suite AG30, Atlanta, GA 30322, USA
| | - Shahriar Iravanian
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - Michael S Lloyd
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA
| | - John N Oshinski
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology / Emory University, 1364 Clifton Road, Suite AG30, Atlanta, GA 30322, USA
- Department of Radiology & Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA
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Hu Y, Gurev V, Constantino J, Trayanova N. Efficient preloading of the ventricles by a properly timed atrial contraction underlies stroke work improvement in the acute response to cardiac resynchronization therapy. Heart Rhythm 2013; 10:1800-6. [PMID: 23928177 PMCID: PMC3852188 DOI: 10.1016/j.hrthm.2013.08.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Indexed: 11/16/2022]
Abstract
BACKGROUND The acute response to cardiac resynchronization therapy (CRT) has been shown to be due to 3 mechanisms: resynchronization of ventricular contraction, efficient preloading of the ventricles by a properly timed atrial contraction, and mitral regurgitation reduction. However, the contribution of each of the 3 mechanisms to the acute response to CRT, specifically stroke work improvement, has not been quantified. OBJECTIVE To use a magnetic resonance image-based anatomically accurate 3-dimensional model of failing canine ventricular electromechanics to quantify the contribution of each of the 3 mechanisms to stroke work improvement and identify the predominant mechanisms. METHODS An MRI-based electromechanical model of the failing canine ventricles assembled previously by our group was further developed and modified. Three different protocols were used to dissect the contribution of each of the 3 mechanisms to stroke work improvement. RESULTS Resynchronization of ventricular contraction did not lead to a significant stroke work improvement. Efficient preloading of the ventricles by a properly timed atrial contraction was the predominant mechanism underlying stroke work improvement. Stroke work improvement peaked at an intermediate atrioventricular delay, as it allowed ventricular filling by atrial contraction to occur at a low diastolic left ventricular pressure but also provided adequate time for ventricular filling before ventricular contraction. Reduction of mitral regurgitation by CRT led to stroke work worsening instead of improvement. CONCLUSION Efficient preloading of the ventricles by a properly timed atrial contraction is responsible for a significant stroke work improvement in the acute CRT response.
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Affiliation(s)
- Yuxuan Hu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Viatcheslav Gurev
- Functional Genomics and Systems Biology, IBM T.J. Watson Research Center, Yorktown Heights, NY, USA
| | - Jason Constantino
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Natalia Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
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Takahashi K, Naruse K. Stretch-activated BK channel and heart function. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2013; 110:239-44. [PMID: 23281538 DOI: 10.1016/j.pbiomolbio.2012.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The heart is an organ that is exposed to extreme dynamic mechanical stimuli. From birth till death, the heart indefinitely repeats periodic contraction and dilation, i.e., shortening and elongation of cardiomyocytes. Mechanical stretch elicits a change in heart rate and may cause arrhythmia if it is excessive. Thus, mechanosensitivity is crucial to heart function. The molecule that is substantially involved in mechanosensitivity is a stretch-activated ion channel. Among several ion channels believed to be activated by stretch in the heart, the stretch-activated KCa (SAKCA) channel, a member of the group of large conductance (Big Potassium, BK) channels, shows a mechanosensitive (MS) response to membrane stretch. As BK channels respond to voltage and intracellular calcium concentration with large conductance, they are considered to be involved in repolarization after depolarization. Some BK channels are known to be activated by stretch and are expressed in a number of cells, including human osteoblasts and guinea pig intestinal neurons. The SAKCA channel was found to be sensitive to stretch in the chick heart. Given that the cardiomyocyte is unremittingly exposed to contraction and dilation and that it generates action potential and its contractility is modulated by intracellular calcium concentration, the SAKCA channel, which is dependent voltage and calcium, may be involved in action potential generation. It was recently reported that a BK channel is involved in the modulation of heart rate in the mouse. Further studies regarding the role of MS BK channels, including SAKCA, in the modulation of heart rate and contractility are expected.
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Affiliation(s)
- Ken Takahashi
- Department of Cardiovascular Physiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
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Constantino J, Hu Y, Lardo AC, Trayanova NA. Mechanistic insight into prolonged electromechanical delay in dyssynchronous heart failure: a computational study. Am J Physiol Heart Circ Physiol 2013; 305:H1265-73. [PMID: 23934857 DOI: 10.1152/ajpheart.00426.2013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In addition to the left bundle branch block type of electrical activation, there are further remodeling aspects associated with dyssynchronous heart failure (HF) that affect the electromechanical behavior of the heart. Among the most important are altered ventricular structure (both geometry and fiber/sheet orientation), abnormal Ca(2+) handling, slowed conduction, and reduced wall stiffness. In dyssynchronous HF, the electromechanical delay (EMD), the time interval between local myocyte depolarization and myofiber shortening onset, is prolonged. However, the contributions of the four major HF remodeling aspects in extending EMD in the dyssynchronous failing heart remain unknown. The goal of this study was to determine the individual and combined contributions of HF-induced remodeling aspects to EMD prolongation. We used MRI-based models of dyssynchronous nonfailing and HF canine electromechanics and constructed additional models in which varying combinations of the four remodeling aspects were represented. A left bundle branch block electrical activation sequence was simulated in all models. The simulation results revealed that deranged Ca(2+) handling is the primary culprit in extending EMD in dyssynchronous HF, with the other aspects of remodeling contributing insignificantly. Mechanistically, we found that abnormal Ca(2+) handling in dyssynchronous HF slows myofiber shortening velocity at the early-activated septum and depresses both myofiber shortening and stretch rate at the late-activated lateral wall. These changes in myofiber dynamics delay the onset of myofiber shortening, thus giving rise to prolonged EMD in dyssynchronous HF.
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Affiliation(s)
- Jason Constantino
- Department of Biomedical Engineering and Institute of Computational Medicine, The Johns Hopkins University, Baltimore, Maryland; and
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Trayanova NA, O'Hara T, Bayer JD, Boyle PM, McDowell KS, Constantino J, Arevalo HJ, Hu Y, Vadakkumpadan F. Computational cardiology: how computer simulations could be used to develop new therapies and advance existing ones. Europace 2013; 14 Suppl 5:v82-v89. [PMID: 23104919 DOI: 10.1093/europace/eus277] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This article reviews the latest developments in computational cardiology. It focuses on the contribution of cardiac modelling to the development of new therapies as well as the advancement of existing ones for cardiac arrhythmias and pump dysfunction. Reviewed are cardiac modelling efforts aimed at advancing and optimizing existent therapies for cardiac disease (defibrillation, ablation of ventricular tachycardia, and cardiac resynchronization therapy) and at suggesting novel treatments, including novel molecular targets, as well as efforts to use cardiac models in stratification of patients likely to benefit from a given therapy, and the use of models in diagnostic procedures.
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Affiliation(s)
- Natalia A Trayanova
- Department of Biomedical Engineering, Institute for Computational Medicine, Johns Hopkins University, Baltimore, MD 21218, USA.
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Effects of mechano-electric feedback on scroll wave stability in human ventricular fibrillation. PLoS One 2013; 8:e60287. [PMID: 23573245 PMCID: PMC3616032 DOI: 10.1371/journal.pone.0060287] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 02/25/2013] [Indexed: 11/19/2022] Open
Abstract
Recruitment of stretch-activated channels, one of the mechanisms of mechano-electric feedback, has been shown to influence the stability of scroll waves, the waves that underlie reentrant arrhythmias. However, a comprehensive study to examine the effects of recruitment of stretch-activated channels with different reversal potentials and conductances on scroll wave stability has not been undertaken; the mechanisms by which stretch-activated channel opening alters scroll wave stability are also not well understood. The goals of this study were to test the hypothesis that recruitment of stretch-activated channels affects scroll wave stability differently depending on stretch-activated channel reversal potential and channel conductance, and to uncover the relevant mechanisms underlying the observed behaviors. We developed a strongly-coupled model of human ventricular electromechanics that incorporated human ventricular geometry and fiber and sheet orientation reconstructed from MR and diffusion tensor MR images. Since a wide variety of reversal potentials and channel conductances have been reported for stretch-activated channels, two reversal potentials, −60 mV and −10 mV, and a range of channel conductances (0 to 0.07 mS/µF) were implemented. Opening of stretch-activated channels with a reversal potential of −60 mV diminished scroll wave breakup for all values of conductances by flattening heterogeneously the action potential duration restitution curve. Opening of stretch-activated channels with a reversal potential of −10 mV inhibited partially scroll wave breakup at low conductance values (from 0.02 to 0.04 mS/µF) by flattening heterogeneously the conduction velocity restitution relation. For large conductance values (>0.05 mS/µF), recruitment of stretch-activated channels with a reversal potential of −10 mV did not reduce the likelihood of scroll wave breakup because Na channel inactivation in regions of large stretch led to conduction block, which counteracted the increased scroll wave stability due to an overall flatter conduction velocity restitution.
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Understanding the mechanisms amenable to CRT response: from pre-operative multimodal image data to patient-specific computational models. Med Biol Eng Comput 2013; 51:1235-50. [PMID: 23430328 DOI: 10.1007/s11517-013-1044-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 02/02/2013] [Indexed: 01/18/2023]
Abstract
This manuscript describes our recent developments towards better understanding of the mechanisms amenable to cardiac resynchronization therapy response. We report the results from a full multimodal dataset corresponding to eight patients from the euHeart project. The datasets include echocardiography, MRI and electrophysiological studies. We investigate two aspects. The first one focuses on pre-operative multimodal image data. From 2D echocardiography and 3D tagged MRI images, we compute atlas based dyssynchrony indices. We complement these indices with presence and extent of scar tissue and correlate them with CRT response. The second one focuses on computational models. We use pre-operative imaging to generate a patient-specific computational model. We show results of a fully automatic personalized electromechanical simulation. By case-per-case discussion of the results, we highlight the potential and key issues of this multimodal pipeline for the understanding of the mechanisms of CRT response and a better patient selection.
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Trayanova NA. Computational cardiology: the heart of the matter. ISRN CARDIOLOGY 2012; 2012:269680. [PMID: 23213566 PMCID: PMC3505657 DOI: 10.5402/2012/269680] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 09/06/2012] [Indexed: 12/19/2022]
Abstract
This paper reviews the newest developments in computational cardiology. It focuses on the contribution of cardiac modeling to the development of new therapies as well as the advancement of existing ones for cardiac arrhythmias and pump dysfunction. Reviewed are cardiac modeling efforts aimed at advancing and optimizing existent therapies for cardiac disease (defibrillation, ablation of ventricular tachycardia, and cardiac resynchronization therapy) and at suggesting novel treatments, including novel molecular targets, as well as efforts to use cardiac models in stratification of patients likely to benefit from a given therapy, and the use of models in diagnostic procedures.
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Affiliation(s)
- Natalia A Trayanova
- Department of Biomedical Engineering and Institute for Computational Medicine, Johns Hopkins University, 3400 North Charles Street, Hackerman Hall Room 216, Baltimore, MD 21218, USA
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Multi-scale simulations of cardiac electrophysiology and mechanics using the University of Tokyo heart simulator. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2012; 110:380-9. [DOI: 10.1016/j.pbiomolbio.2012.07.001] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 07/11/2012] [Indexed: 11/20/2022]
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Kohl P, Bollensdorff C, Morad M. Progress in Biophysics and Molecular Biology of the Beating Heart. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2012; 110:151-3. [DOI: 10.1016/j.pbiomolbio.2012.08.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 08/09/2012] [Indexed: 12/14/2022]
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