Hypertrophic obstructive cardiomyopathy (HOCM) is best described as:

• A. A form of dilated cardiomyopathy
• B. An autosomal dominant condition
• C. A viral myocarditis
• D. A pericardial disease

Answer: (B)

HOCM is a genetic heart muscle disease most often inherited in an autosomal dominant pattern due to mutations in sarcomeric protein genes. This autosomal dominant transmission explains why many families show the condition across generations, with variable expression and penetrance. The hallmark is asymmetric thickening of the interventricular septum that can create dynamic obstruction of the left ventricular outflow tract, often with systolic anterior motion of the mitral valve. This distinguishes it from dilated cardiomyopathy (which would have dilated ventricles and reduced function), viral myocarditis (inflammation of the heart muscle), and pericardial disease (issues centered on the heart’s outer lining). So, the best description is that it is an autosomal dominant genetic condition.