A heart that undergoes dilated cardiomyopathy shows unique enlargement of ventricles, and thinning of the ventricular wall that may lead to heart failure.
Possible explanations include shortening of ventricular refractoriness (i.e. delayed reactivation of sodium channels) and altered sequence of depolarization and hence inhomogeneity of ventricular repolarization.
The electrocardiogram often shows sinus tachycardia or atrial fibrillation, ventricular arrhythmias, left atrial enlargement, and sometimes intraventricular conduction defects and low voltage.
Left or right ventricular systolic pump function of the heart is impaired, leading to progressive cardiac enlargement and hypertrophy, a process called "remodeling".