Dilated cardiomyopathy
Dilated cardiomyopathy is left ventricular (often biventricular) dilation with systolic dysfunction not explained by loading conditions or coronary disease, from genetic, viral, toxic, or peripartum causes, presenting as heart failure with reduced ejection fraction. Diagnosis is by echocardiography with a workup for reversible causes, and treatment is guideline-directed heart-failure therapy with device therapy for high-risk patients.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
Definition: dilated cardiomyopathy is dilation and impaired contraction of the left (often both) ventricle not explained by abnormal loading conditions or coronary artery disease.
- Epidemiology
A common cause of heart failure and the leading indication for heart transplantation.
- Risk factors
Family history / genetic mutation: titin and lamin A/C among others.
- Pathophysiology
Myocyte injury and remodeling: genetic, toxic, or inflammatory insults impair contractility, and compensatory dilation and neurohormonal activation drive progressive remodeling.
- Clinical features
Heart failure symptoms: exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, fatigue, and edema.
- Differential diagnosis
Ischemic cardiomyopathy: a low ejection fraction with regional wall-motion abnormalities in a coronary distribution and obstructive disease on angiography, the discriminator being significant…
- Diagnosis
Establish with echocardiography showing a dilated, hypocontractile ventricle after excluding coronary and loading causes: the diagnostic basis is echocardiography demonstrating left ventricular…
- Management
First-line, guideline-directed medical therapy for HFrEF, starting the four pillars and titrating each to the target dose over weeks: An angiotensin receptor-neprilysin inhibitor…
- Complications
Progressive heart failure and cardiogenic shock (acute heart failure).
- Prognosis
Improved by guideline-directed therapy: modern medical and device therapy substantially improves survival.
- Prevention
Avoid cardiotoxins: limit alcohol and monitor cardiac function during cardiotoxic chemotherapy.
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.
Related articles
- Heart failure
Heart failure is a clinical syndrome of impaired cardiac filling or ejection causing congestion and reduced perfusion, classified by ejection fraction. Diagnosis integrates symptoms, signs, natriuretic peptides, and echocardiography, and treatment of reduced-ejection-fraction disease is quadruple guideline-directed therapy, with device therapy and cause-specific management.
- Acute heart failure
Acute heart failure is the rapid onset or worsening of heart failure symptoms requiring urgent therapy, most often pulmonary congestion from a precipitant such as ischemia, arrhythmia, or nonadherence. Management is oxygen, intravenous diuretics, and vasodilators for the congested-but-perfused patient, with inotropes or support for the hypoperfused patient.
- Myocarditis
Myocarditis is inflammation of the myocardium, most often postviral or immune-mediated, presenting across a spectrum from a mild chest-pain syndrome mimicking myocardial infarction to fulminant heart failure and arrhythmia. Diagnosis relies on cardiac MRI (or biopsy for severe or refractory cases), and treatment is supportive heart-failure care, with cause-specific immunosuppression for giant cell, checkpoint-inhibitor, and autoimmune myocarditis.
- Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy is an autosomal dominant sarcomere disease causing unexplained left ventricular hypertrophy, often with dynamic left ventricular outflow tract obstruction, and is a leading cause of sudden cardiac death in young people. Diagnosis is by echocardiography or cardiac MRI showing unexplained hypertrophy, and management includes negative inotropes, obstruction relief, and ICD placement for high sudden-death risk.