This project focuses on biophysical principles of arrhythmogenic mechanisms underlying two inherited diseases: arrhythmogenic right ventricular cardiomyopathy (ARVC) and catecholaminergic polymorphic ventricular tachycardia (CPVT). In both cases, arrhythmias and sudden cardiac death (SCO) develop. However, the specific mechanisms underlying ventricular tachycardia/fibrillation (VTA/F) and SCO in either ARVC or CPVT patients has not yet been resolved. In ARVC, arrhythmias may result from impaired mechanical coupling between cardiomyocytes due to mutations in desmosomal proteins, which may lead to dysfunction of the intercalated disk, and eventual disruption of gap junction plaques, myocyte death and fibro-fatty replacement. In CPVT arrhythmias are the result of abnormal calcium regulation due to leaky mutated ryanodine type-2 receptor channels in the sarcoplasmic reticulum. Yet, it is unknown whether the arrhythmias originate in the 3-dimensional myocardium or in the more isolated, cable-like Purkinje network. Our general hypothesis is that regardless of the mechanism(s) by which arrhythmias are triggered in ARVC and CPVT, the final common pathway in the mechanism underlying VTA/F is wavebreak and reentry. The project combines expertise in cell culture, optical mapping, histopathology, immunohistochemistry and computer modeling to provide testable predictions about how alterations of either structural or Ca2+ regulatory proteins translate into electrical abnormalities that ultimately result in VTA/F and SCO. We propose four Specific Aims: 1) To determine electrophysiological consequences of fibroblast replacement of myocytes and of alterations in intercellular coupling in ventricular constructs and their role in the genesis of reentry in ARVC. 2) To establish the individual roles of alterations in intercellular coupling and fibro-fatty deposits in the genesis of arrhythmias in 3D models of the dysplasic right ventricle. 3) To investigate mechanisms of triggering and maintenance of reentry in biological and numerical models using 2D patterns of CPVT-like mutated mouse cells, mimicking the Purkinje network and the Purkinje-muscle junction. 4) To investigate mechanisms of VT initiation and the transition to VF in simulations using a realistic 3D model of the CPVT-like mutated mouse heart. The proposed work should provide new insight into arrhythmia mechanisms in diseases leading to alterations in the structural and functional homeostasis of the heart.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL087226-04
Application #
8122106
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
Project End
Budget Start
2010-09-01
Budget End
2012-02-29
Support Year
4
Fiscal Year
2010
Total Cost
$289,223
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Type
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
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Rodrigo, M; Climent, A M; Liberos, A et al. (2017) Minimal configuration of body surface potential mapping for discrimination of left versus right dominant frequencies during atrial fibrillation. Pacing Clin Electrophysiol 40:940-946
Rodrigo, Miguel; Climent, Andreu M; Liberos, Alejandro et al. (2017) Highest dominant frequency and rotor positions are robust markers of driver location during noninvasive mapping of atrial fibrillation: A computational study. Heart Rhythm 14:1224-1233
Quintanilla, Jorge G; Pérez-Villacastín, Julián; Pérez-Castellano, Nicasio et al. (2016) Mechanistic Approaches to Detect, Target, and Ablate the Drivers of Atrial Fibrillation. Circ Arrhythm Electrophysiol 9:e002481
Pedrón-Torrecilla, Jorge; Rodrigo, Miguel; Climent, Andreu M et al. (2016) Noninvasive Estimation of Epicardial Dominant High-Frequency Regions During Atrial Fibrillation. J Cardiovasc Electrophysiol 27:435-42
Herron, Todd J; Rocha, Andre Monteiro Da; Campbell, Katherine F et al. (2016) Extracellular Matrix-Mediated Maturation of Human Pluripotent Stem Cell-Derived Cardiac Monolayer Structure and Electrophysiological Function. Circ Arrhythm Electrophysiol 9:e003638
Guillem, María S; Climent, Andreu M; Rodrigo, Miguel et al. (2016) Presence and stability of rotors in atrial fibrillation: evidence and therapeutic implications. Cardiovasc Res 109:480-92
Willis, B Cicero; Pandit, Sandeep V; Ponce-Balbuena, Daniela et al. (2016) Constitutive Intracellular Na+ Excess in Purkinje Cells Promotes Arrhythmogenesis at Lower Levels of Stress Than Ventricular Myocytes From Mice With Catecholaminergic Polymorphic Ventricular Tachycardia. Circulation 133:2348-59
Corrado, Domenico; Zorzi, Alessandro; Cerrone, Marina et al. (2016) Relationship Between Arrhythmogenic Right Ventricular Cardiomyopathy and Brugada Syndrome: New Insights From Molecular Biology and Clinical Implications. Circ Arrhythm Electrophysiol 9:e003631
Jalife, José; Filgueiras Rama, David; Berenfeld, Omer (2015) Letter by Jalife et al Regarding Article, ""Quantitative Analysis of Localized Sources Identified by Focal Impulse and Rotor Modulation Mapping in Atrial Fibrillation"". Circ Arrhythm Electrophysiol 8:1296-8

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