A 45-year-old man presents with sudden onset exertional syncope and dyspnoea. Echocardiogram shows asymmetric septal hypertrophy (IVS = 22 mm, posterior wall = 11 mm), systolic anterior motion of the mitral valve, and LVOT gradient of 70 mmHg at rest. Which drug should be avoided in this condition?

• A Digoxin ✓
• B Beta-blockers (propranolol)
• C Disopyramide (class Ia antiarrhythmic)
• D Verapamil

Explanation

In obstructive hypertrophic cardiomyopathy (HCM), digoxin is contraindicated because its positive inotropic effect increases LVOT gradient by enhancing septal contraction and worsening obstruction. Additionally, digoxin increases heart rate, reducing diastolic filling time. Beta-blockers (first-line), disopyramide (negative inotrope that reduces SAM), and verapamil (improves diastolic function) are all used therapeutically in HCM.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.