Left or biventricular dilatation with structural and/or functional systolic dysfunction in the absence of coronary artery disease, abnormal loading pressures (e.g., valvular heart disease, hypertension), or congenital heart disease

Epidemiology

Etiology

Primary causes

• Idiopathic
• Familial, due to mutations in genes that encode components for sarcomeres and desmosomes
  • TTN gene: encodes the intrasarcomeric protein titin (connectin)

Secondary causes

• Substance use
  • Alcohol use disorder
  • Cocaine
• Cardiotoxic medications, e.g., anthracyclines (such as doxorubicin and daunorubicin), AZT, trastuzumab
• Infection (infectious myocarditis)
  • Coxsackie B virus infection
  • Chagas disease
  • HIV infection
• Infiltrative and autoimmune disorders
  • Systemic lupus erythematosus
  • Sarcoidosis
  • Vasculitides, e.g., eosinophilic granulomatosis with polyangiitis, polyarteritis nodosa
• Hemochromatosis
• Peripartum cardiomyopathy (can occur in the last trimester or up to 6 months postpartum)

Pathophysiology

Decreased LV contractility due to dilation leads to left heart failure and eventually right heart failure

Clinical features

Diagnostics

Treatment

Complications

• Heart failure
• Thromboembolism (e.g., stroke, pulmonary embolism, acute mesenteric ischemia)
• Arrhythmias (e.g., atrial fibrillation, ventricular tachycardia, ventricular fibrillation)
• Sudden cardiac death