A 58-year-old man with severe aortic stenosis (valve area 0.7 cm², mean gradient 52 mmHg) is scheduled for elective laparoscopic cholecystectomy. Which haemodynamic goal is MOST critical during induction of general anaesthesia?
- A Maintain heart rate 80–100 bpm; tolerate brief hypotension
- B Reduce afterload aggressively to decrease transvalvular gradient
- C Maintain normal sinus rhythm, adequate preload, and avoid tachycardia ✓
- D Allow heart rate to rise to compensate for fixed stroke volume
Correct answer: C. Maintain normal sinus rhythm, adequate preload, and avoid tachycardia
Explanation
Severe aortic stenosis produces a fixed cardiac output because the hypertrophied, non-compliant left ventricle is preload-dependent and poorly tolerates tachycardia (reduces diastolic filling time) or sudden afterload reduction (precipitates coronary ischaemia). Normal sinus rhythm and adequate preload must be preserved. Tachycardia reduces coronary perfusion of the hypertrophied LV and should be avoided; aggressive afterload reduction causes severe hypotension because the LV cannot increase output through the fixed obstruction.
Reference: Morgan & Mikhail's Clinical Anesthesiology, 6th ed.
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Written and medically reviewed by the StethoPrep medical team.