Sotalol QT Monitoring — EECC MCQ
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Correct answer: C — ECG QTc and renal-function monitoring
Sotalol has a dual mechanism: (1) non-selective beta-blocker (class II effect — rate slowing, anti-ischaemic); (2) potassium channel blocker (class III effect — prolongs action potential duration and QT interval). The class III effect creates QT prolongation risk → torsades de pointes (TdP) → VF → SCD. Risk is dose-dependent and increased by: hypokalaemia, hypomagnesaemia, renal impairment (sotalol is 100% renally cleared), female sex, bradycardia, and concomitant QT-prolonging drugs. The 2024 ESC AF Guidelines recommend: (1) baseline ECG with QTc measurement; (2) initiation in a monitored setting (some centres); (3) ECG 2-3 days after starting and after each dose increase; (4) maintain K⁺ >4.0 and Mg²⁺ >0.8 mmol/L; (5) stop if QTc >500 ms or QTc increase >60 ms from baseline; (6) avoid in HFrEF (negative inotropy + proarrhythmia); (7) reduce dose in CKD (eGFR <60: halve the dose; <30: contraindicated).
Reference: ESC (2024): AF Guidelines; BNF: https://bnf.nice.org.uk/