Among the cardiomyopathy categories, which accounts for the majority of cases?

• A. Dilated
• B. Hypertrophic
• C. Restrictive
• D. Arrhythmogenic right ventricular cardiomyopathy

Answer: (A)

Dilated cardiomyopathy is the most common form of cardiomyopathy overall. It features dilation of the ventricles, especially the left ventricle, with impaired systolic function and reduced ejection fraction. Because it represents the majority of primary cardiomyopathy cases seen in adults, it accounts for most of the conditions categorized under cardiomyopathies. The other types—hypertrophic (thickened walls with often diastolic dysfunction), restrictive (stiff ventricles with diastolic dysfunction), and arrhythmogenic right ventricular cardiomyopathy (fibrofatty changes mainly in the right ventricle with arrhythmias)—are less common overall. So, the reason this choice is correct is that dilated cardiomyopathy is simply the most frequent category among cardiomyopathies.