140. What are the causes of congestive heart failure in patients with hypertrophic obstructive cardiomyopathy?

Also known as hypertrophic obstructive cardiomyopathy (HOCM), this disease results in abnormal hypertrophic changes most commonly in the interventricular septum with pathologic “myocardial disarray”. HOCM is familial in about 50% of cases and transmitted in an autosomal dominant fashion. HOCM can result in clinic heart failure, life-threatening arrhythmias, mitral regurgitation and sudden cardiac death. 

The causes of heart failure in HOCM include:

1. Diastolic dysfunction
2. Mitral regurgitation
3. Arrhythmia
4. End-stage HOCM results in systolic dysfunction “burnt-out HOCM”