Abstract
Cardiac mechanical and electrical activities are interrelated closely. The interrelationships between these are constructed with Mechano-Electric Feedback(MEF), however less is known about cellular mechanisms of it. Recent progress on ventricular assist device therapy for myocardial recovery has been indicated the possibilities to improve the failed heart function normally. As one of the mechanisms to suppress or reverses the remodeling of cardiac myocyte following to heart failure, mechanical unloading has been assumed to be a necessary factor for cardiac function recovery. However, less is known for this mechanism and strategies for effective therapy. To speculate the mechanism of myocardial recovery following to mechanical unloading, the effects of differential contraction manner including isotonic and isometric contraction for action potentials(APs)were evaluated with numerical analysis. The excitation-contraction coupling was modeled with the combination of action potential model(LRd model)and contractile force generation model(NL model). The other pathway for construction of MEF was realized by an incorporation of stretch-activated channels. The differences of action potential duration between isometric or isotonic contraction are very limited on normalion concentration condition, however, the crossover of AP was observed on calcium-overloaded condition. Moreover, arrhythmogenic responses are indicated on isotonic contraction with calcium-overloaded condition.
