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Atrial fibrillation triggered by sepsis — SCE Acute Medicine MCQ

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HardCardiovascular medicineAtrial fibrillation triggered by sepsisSCE Acute Medicine

A 76-year-old man with pneumonia develops atrial fibrillation at 150/min. Blood pressure is 104/62 mmHg after fluids, oxygen saturation is 94% on 2 L/min and lactate is falling from 3.1 to 1.8 mmol/L. He has no chest pain or pulmonary oedema. Potassium is 3.3 mmol/L and magnesium is 0.62 mmol/L. What is the most appropriate next step in management?

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Correct answer: B — Treat sepsis, correct electrolytes and consider cautious rate control if tachycardia persists

AF during acute infection often improves when the trigger is treated and electrolyte abnormalities are corrected; urgent cardioversion is reserved for arrhythmia-driven shock, ischaemia or pulmonary oedema. Flecainide is unsuitable in many older acutely ill patients and does not address the precipitant. The distinction is whether AF is the cause of instability or a marker of systemic illness.

Reference: NICE NG196 atrial fibrillation; Resuscitation Council UK ALS