Diagnosis and management of dilated cardiomyopathy

Dilated cardiomyopathy is a heart muscle disorder defined by the presence of a dilated and poorly functioning left ventricle in the absence of abnormal loading conditions (hypertension, valve disease) or ischaemic heart disease sufficient to cause global systolic impairment. A large number of cardiac and systemic diseases can cause systolic impairment and left ventricular dilatation, but in the majority of patients no identifiable cause is found—hence the term “idiopathic” dilated cardiomyopathy (IDC). There are experimental and clinical data in animals and humans suggesting that genetic, viral, and immune factors contribute to the pathophysiology of IDC.#### Causes of dilated cardiomyopathy Young Adolescent/adults ### Clinical presentation The first presentation of IDC may be with systemic embolism or sudden death, but patients more typically present with signs and symptoms of pulmonary congestion and/or low cardiac output, often on a background of exertional symptoms and fatigue for many months or years before their diagnosis. Intercurrent illness or the development of arrhythmia, in particular atrial fibrillation, may precipitate acute decompensation in such individuals. Increasingly, IDC is diagnosed incidentally in asymptomatic individuals during routine medical screening or family evaluation of patients with established diagnosis. A careful family history facilitates diagnosis of inherited causes of IDC by characterising the family phenotype, and also defines the scope of family screening.1 At least 25% of patients have evidence for familial disease with predominantly autosomal dominant inheritance. Clinically, familial disease is defined by the presence of two or more affected individuals in a single family and should also be suspected in all patients with …