<unk>  is the spontaneous depolarization and repolarization event that occurs in a repetitive and stable manner within the cardiac muscle.<unk>  is often abnormal or lost in cases of cardiac dysfunction or cardiac failure. It is the ability of the heart to maintain a relatively stable relation between its systole and diastole. Not increasing one on the expense of the other. However, external factors may lead to the disruption of the heart's<unk> .
Cardiac rhythmicity
Myogenic tone
Myocardial contractility
Premovement neuronal activity
Electrodermal activity
Cardiac reserve
Cardiac excitation-contraction coupling
Cardiac cycle