In hypertrophic obstructive cardiomyopathy, which is a first-line therapy for reducing exertional symptoms?

• A. Nitrates
• B. Beta blocker
• C. AICD
• D. Calcium channel blocker

Answer: (B)

In hypertrophic obstructive cardiomyopathy, the main problem during exertion is a dynamic LV outflow tract obstruction that gets worse with faster heart rate and more forceful contractions. A beta-blocker directly counteracts this by slowing the heart rate and reducing contractility, which decreases the obstruction and improves diastolic filling. By lowering the LVOT gradient during activity, it alleviates exertional symptoms like dyspnea and chest tightness. Nitrates tend to reduce preload and can worsen the obstruction, AICD is aimed at preventing sudden death rather than relieving symptoms, and calcium channel blockers are options if beta-blockers can’t be used but aren’t the first-line choice. Therefore, a beta-blocker is the best initial therapy for reducing exertional symptoms.