Coronary ligation-induced heart failure in rabbits caused extensive structural, neuronal, and electrophysiological remodeling, providing substrates for ventricular arrhythmias.
RCT (n=25)
randomized
Does coronary ligation-induced heart failure alter the autonomic neuro-cardiac profile and cause electrical, structural, and neuronal remodeling in a rabbit model?
This rabbit model demonstrates that MI-induced heart failure leads to extensive structural, neuronal, and electrophysiological remodeling, providing a substrate for ventricular arrhythmias.
Heart failure is a clinical syndrome typified by abnormal autonomic tone, impaired ventricular function, and increased arrhythmic vulnerability. This study aims to examine electrophysiological, structural and neuronal remodeling following myocardial infarction in a rabbit heart failure model to establish its neurocardiac profile. Weight-matched adult male New Zealand White rabbits (3.2 ± 0.1 kg, n = 25) were randomized to have coronary ligation surgeries (HF group, n = 13) or sham procedures (SHM group, n = 12). Transthoracic echocardiography was performed six weeks post-operatively. On week 8, dual-innervated Langendorff-perfused heart preparations were set up for terminal experiments. Seventeen hearts (HF group, n = 10) underwent ex-vivo cardiac MRI. Twenty-two hearts (HF group, n = 7) were examined histologically. Electrical remodeling and abnormal autonomic profile were evident in HF rabbits with exaggerated sympathetic and attenuated vagal effect on ventricular fibrillation threshold, ventricular refractoriness and restitution curves, in addition to increased spatial restitution dispersion. Histologically, there was significant neuronal enlargement at the heart hila and conus arteriosus in HF. Structural remodeling was characterized by quantifiable myocardial scarring, enlarged left ventricles, altered ventricular geometry and impaired contractility. In an infarct-induced rabbit heart failure model, extensive structural, neuronal and electrophysiological remodeling in conjunction with abnormal autonomic profile provide substrates for ventricular arrhythmias.
Chin et al. (Wed,) conducted a rct in myocardial infarction-induced heart failure (n=25). Coronary ligation vs. Sham procedures was evaluated on electrophysiological, structural and neuronal remodeling. Coronary ligation-induced heart failure in rabbits caused extensive structural, neuronal, and electrophysiological remodeling, providing substrates for ventricular arrhythmias.