Cardiomyopathiesdilated

Dilated cardiomyopathy (DCM) is a form of heart disease characterized by dilation of the left and/or right ventricles and impaired systolic function. It is defined by ventricular enlargement with reduced ejection fraction, typically 40% or less, in the absence of other conditions that would explain the dysfunction, such as significant valve disease or severe hypertension. DCM can present at any age and may occur sporadically or in a familial pattern; genetic forms account for a substantial minority of cases.

Etiology and pathophysiology are diverse. Genetic mutations, especially in TTN, LMNA, and MYH7 among others, underlie many inherited cases. Acquired causes include ischemic heart disease, viral myocarditis, alcohol or drug toxicity (notably anthracyclines), pregnancy-related factors, tachycardia-induced cardiomyopathy, and autoimmune conditions. The disease process involves myocardial injury and remodeling with fibrosis, leading to progressive systolic dysfunction, heart failure symptoms, and an elevated risk of arrhythmias and thromboembolism.

Clinical presentation and diagnosis rely on imaging and biomarkers. Patients commonly report dyspnea on exertion, fatigue, edema, orthopnea, and palpitations. Diagnosis is supported by echocardiography showing dilated ventricles with reduced function; MRI can provide tissue characterization and detect fibrosis. Laboratory tests include natriuretic peptides and assessments to exclude ischemia. In some cases, genetic testing and family screening are recommended to identify relatives at risk.

Management focuses on reducing heart failure progression and preventing complications. Guideline-directed medical therapy includes ACE inhibitors or ARBs or sacubitril/valsartan, beta-blockers, mineralocorticoid receptor antagonists, and diuretics for congestion, with consideration of SGLT2 inhibitors. Device therapies (ICD or CRT) are used in selected patients, and advanced cases may require heart transplantation. Prognosis varies with severity and response to therapy.