Dilated cardiomyopathies (DCM) represent a range of myocardial disorders characterized by left and right ventricular dilatation and reduced myocardial contractility. Prevalence is estimated at about 36 cases per 100 000. DCM typically presents at 30-60 years of age. African Americans have an almost 3-fold increased risk for developing DCM.

DCM may have an ischemic or nonischemic etiology. Nonischemic causes include inherited muscular disease, chemotherapy (eg, anthracyclines), endocrinopathies (eg, thyrotoxicosis, pheochromocytoma), infiltrative diseases (eg, amyloidosis), alcohol use disorder, and viral myocarditis. Genetic causes include mutations in genes encoding cardiac sarcomere and cytoskeletal proteins. Many cases are idiopathic.

Patients usually present with symptoms of heart failure including dyspnea, edema, orthopnea, and weight gain. Physical examination may reveal signs of acute left ventricular failure, such as S3 gallop, systolic murmur consistent with mitral regurgitation, pleural effusions, jugular venous distension, and/or peripheral edema.