Cardiomyopathy

Cardiomyopathy is a disease of the heart muscle that impairs the heart's ability to pump blood. It refers to disorders in which the primary problem lies in the myocardium rather than in coronary artery disease, valvular disease, or hypertension, and it can be inherited or acquired.

The main forms are dilated, hypertrophic, restrictive, and arrhythmogenic right ventricular cardiomyopathy. Dilated cardiomyopathy features enlarged ventricles and reduced systolic function; hypertrophic cardiomyopathy involves thickened heart walls; restrictive cardiomyopathy has stiff ventricles that impair filling; ARVC involves fibrofatty replacement of the right ventricle. Some cases are unclassified.

Causes include genetic mutations and acquired factors such as viral infections, autoimmune or metabolic diseases, toxins such as alcohol, and long-standing hypertension or prior heart injury. Many cases remain idiopathic.

Symptoms vary but commonly include shortness of breath, fatigue, swelling of the legs or abdomen, palpitations, lightheadedness, or chest discomfort. Signs of heart failure or arrhythmias may be present.

Diagnosis relies on imaging and testing. Echocardiography is typically first-line to assess chamber size and function, with cardiac MRI and ECG for further evaluation. Genetic testing may be used in familial cases. Coronary disease is usually evaluated to exclude ischemic causes.

Treatment focuses on relieving symptoms and preventing complications. Standard heart failure therapies—such as inhibitors of the renin–angiotensin system, beta-blockers, diuretics, and mineralocorticoid receptor antagonists—are commonly used, along with anticoagulation when indicated. Device therapy (pacemakers or defibrillators) and, in severe disease, transplantation or ventricular assist devices may be required. Prognosis varies by form and severity.