What is the most common cause of non-ischemic dilated cardiomyopathy in the United States?

• A. Chronic alcoholism
• B. Viral myocarditis
• C. Hypertension
• D. Autoimmune disease

Answer: (A)

Chronic alcohol use is the most common nonischemic cause of dilated cardiomyopathy in the United States. Alcohol is directly toxic to the myocardium, leading to myocyte injury, impaired mitochondrial function, and reduced contractility. Over time this toxic effect causes the left ventricle to dilate and systolic performance to weaken, producing a dilated cardiomyopathy pattern.

Other etiologies like viral myocarditis, hypertension, or autoimmune disease can cause dilated cardiomyopathy, but they are less commonly identified as the primary nonischemic cause in typical U.S. patient cohorts. Hypertension more classically drives hypertensive heart disease with concentric remodeling and potential systolic dysfunction, while autoimmune processes and viral myocarditis are important but less frequent culprits compared with alcohol exposure. Importantly, if alcohol exposure is removed, some patients may experience partial or substantial improvement, highlighting the reversible aspect of alcoholic cardiomyopathy.