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Unstable complete heart block — SCE Acute Medicine MCQ

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ModerateCardiovascular medicineUnstable complete heart blockSCE Acute Medicine

A 79-year-old woman is admitted after syncope. ECG shows complete heart block with a ventricular rate of 32/min and broad QRS complexes. BP is 84/46 mmHg despite lying flat, and she has pulmonary oedema. Atropine 500 micrograms IV produces no response. What is the most appropriate next step in management?

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Correct answer: B — Arrange immediate transcutaneous pacing while preparing for transvenous pacing

Complete heart block with shock and heart failure is an unstable bradyarrhythmia requiring immediate pacing when atropine fails. Transcutaneous pacing is an interim measure while expert help and transvenous pacing are arranged. Adenosine and observation are inappropriate in an unstable patient with high-grade AV block.

Reference: Resuscitation Council UK ALS 2025