Dilated Cardiomyopathy

Key points

• Dilated heart leading to systolic (± diastolic) dysfunction · all 4 chambers affected but LV more than RV · features include arrhythmias, emboli, mitral regurgitation · absence of congenital, valvular or ischaemic heart disease
• Causes often considered separate entities: alcohol (may improve with thiamine) · postpartum · hypertension
• Other causes: infections (Coxsackie B, HIV, diphtheria, parasitic) · endocrine (hyperthyroidism) · infiltrative (haemochromatosis, sarcoidosis — may also cause restrictive pattern) · neuromuscular (Duchenne) · nutritional (kwashiorkor, pellagra, thiamine/selenium deficiency) · drugs (doxorubicin)
• Around a third of patients have a genetic predisposition — mostly autosomal dominant
• Wilson's disease association is extremely rare · viral myocarditis (parvovirus B19 and HHV-6 now the most common causes) can precipitate DCM and cardioembolic stroke