Idiopathic dilated cardiomyopathy (IDCM) has been defined by the World Health Organization as dilatation of the left, right or both ventricles, with impaired contractility of unknown cause.  It is a common form of dilated cardiomyopathy that produces symptoms of heart failure in patients of any age or sex.  Overt congestive heart failure may or may not be present, arrhythmia's are common, and the prognosis is often poor.   

The symptoms of IDCM can range from none to life-threatening.  Mostly, patients suffer from symptoms due to congestive heart failure.  These include shortness of breath, cough, fatigue, and swelling of the ankles.  Patients with idiopathic dilated cardiomyopathy may also have an irregular heart rhythm and even episodes of fainting.  Abdominal pain is fairly common and is due to distention of the liver with excessive fluid.  The physical examination shows the signs of heart failure.  Usually, there is engorgement of the veins in the neck.  There may be congestion of the lungs and liver.  There are abnormal additional heart sounds and often murmurs.