Skip to Main Content

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

  • Left ventricular dilation and systolic dysfunction in the absence of an identifiable etiology or abnormal loading conditions

GENERAL CONSIDERATIONS

  • Disease is 3 times more common in African-Americans

  • Emerging data suggest that 20–35% of patients with an idiopathic dilated cardiomyopathy may have familial disease

  • Some patients may have had an undetected viral myocarditis

  • Patients have a lower total mortality rate when compared to other types of dilated cardiomyopathy

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

  • Decreased exercise tolerance

  • Dyspnea

  • Orthopnea

  • Paroxysmal nocturnal dyspnea

  • Fatigue

  • Palpitations

  • Presyncope or syncope

PHYSICAL EXAM FINDINGS

  • Tachycardia

  • Tachypnea

  • Jugular venous distention may be present

  • Pulmonary rales

  • Laterally displaced and diffuse point of maximal impulse; left and right ventricular lifts

  • Soft S1, paradoxically split S2 with a left bundle branch block

  • S3 and S4 gallops

  • Hepatomegaly due to elevated venous pressures; the liver may be pulsatile with severe tricuspid regurgitation

  • Ascites, peripheral edema

  • Muscle wasting or other signs of cardiac cachexia

DIFFERENTIAL DIAGNOSIS

  • Ischemic cardiomyopathy

  • Valvular heart disease

  • Hypertensive heart disease

  • Toxin-induced cardiomyopathy: alcohol, stimulants (cocaine, methamphetamine), cytotoxic antineoplastic drugs

  • Cardiomyopathy related to thyroid dysfunction

  • HIV or other inflammatory cardiomyopathy

DIAGNOSTIC EVALUATION

LABORATORY TESTS

  • Electrolytes, blood urea nitrogen, and creatinine

  • CBC

  • Liver function tests

  • Cardiac enzymes

  • Thyroid function tests, iron studies

  • Urine pregnancy test: in women of childbearing age

  • Urine toxicology screen

  • HIV antibody testing

ELECTROCARDIOGRAPHY

  • Supraventricular tachycardia

  • Premature ventricular complexes

  • Nonspecific ST- and T-wave changes

  • Left ventricular hypertrophy or biventricular hypertrophy

  • Left bundle branch block common

  • Varying degrees of atrioventricular block may be present

IMAGING STUDIES

  • Chest x-ray:

    • – Enlarged cardiac silhouette

    • – Pulmonary vascular congestion

    • – Pleural effusions

  • Echocardiography:

    • – All 4 cardiac chambers are typically enlarged, and ventricular contractile function is reduced

    • – Varying degrees of mitral and tricuspid regurgitation due to annular dilatation

  • Cardiac magnetic resonance (CMR) to evaluate for possible inflammatory myocarditis as etiology

DIAGNOSTIC PROCEDURES

  • Left heart catheterization with coronary angiography performed to exclude coronary artery disease

  • Endomyocardial biopsy can be considered for patients suspected of inflammatory myocarditis, those with rapidly progressive heart failure, or those with ventricular dysfunction that persists despite medical therapy

  • Cardiopulmonary exercise testing can aid in understanding functional status, evaluating etiologies for exercise limitation, and informing prognosis

TREATMENT

CARDIOLOGY REFERRAL

  • Any patient with symptomatic or asymptomatic ventricular dysfunction

HOSPITALIZATION CRITERIA

  • Decompensated heart failure

  • Atrial fibrillation with rapid ventricular response

  • Syncope

  • Cardiac arrest

MEDICATIONS

  • Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.