Idiopathic Dilated Cardiomyopathy: definition Posted by: Cleo Libonati, RN, BSN in DICTIONARY 0 2,437 Views A cardiac disorder of myocardial (heart muscle) function characterized by dilation of the cardiac chambers and reduction in the ability of the ventricles (lower chambers) to contract often resulting in symptomatic heart failure. Dyspnea Edema Glossary. Heart Chambers Heart Disorders Heart Failure Heart Musle Idiopathic Dilated Cardiomyopathy Myocardial Function Rapid Heartbeat Shortness of Breath Tachycardia Weakness 2013-04-10 Cleo Libonati, RN, BSN