A 40-year-old man presents with exertional dyspnoea, syncope during exercise, and a 4th heart sound. His father died suddenly at 42. ECG shows LVH and a septal Q wave in leads I and aVL. Echocardiography shows an asymmetric septal hypertrophy of 24 mm with systolic anterior motion of the mitral valve and an LVOT gradient of 65 mmHg at rest. The most appropriate initial pharmacological therapy is:

• A Digoxin to improve cardiac contractility
• B ACE inhibitor for remodelling
• C Beta-blocker (metoprolol or bisoprolol) as first-line for symptom relief and gradient reduction ✓
• D Nifedipine (dihydropyridine calcium channel blocker)

Explanation

Hypertrophic obstructive cardiomyopathy (HOCM) with symptomatic LVOT obstruction is treated first with negative inotropes to reduce dynamic obstruction. Beta-blockers are the first-line pharmacological therapy, reducing heart rate, increasing diastolic filling time, and decreasing the LVOT gradient. Dihydropyridine calcium channel blockers (nifedipine) are contraindicated as their vasodilatory effects worsen obstruction. ACE inhibitors reduce afterload and worsen LVOT gradient. Digoxin increases contractility and is contraindicated.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.