A patient with hypertrophic obstructive cardiomyopathy (HOCM) develops hypotension under general anaesthesia. Which intervention is MOST appropriate?

• A Dopamine infusion to increase cardiac output
• B Atropine to increase heart rate and cardiac output
• C Nitroglycerine to reduce outflow tract obstruction
• D IV fluid bolus and phenylephrine ✓

Explanation

In HOCM, hypotension is managed by increasing preload (IV fluids) and systemic vascular resistance (phenylephrine). The dynamic LVOT obstruction worsens with reduced preload, decreased SVR, or tachycardia — all of which increase the gradient. Pure vasoconstrictors without inotropic effect (phenylephrine, noradrenaline) are preferred. Inotropes (dopamine, dobutamine) and vasodilators (nitroglycerin) are contraindicated as they worsen obstruction; tachycardia reduces diastolic filling time worsening diastolic dysfunction.

Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.