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Long QT Syndrome — EECC MCQ

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HardArrhythmia & ElectrophysiologyLong QT SyndromeEECC

A 42-year-old man collapses while playing football. Bystanders perform CPR and an AED delivers one shock, restoring sinus rhythm. His resting ECG shows a corrected QT interval (QTc) of 520 ms with bifid T-waves in the precordial leads. Echocardiography and CMR are normal. Family history reveals his father died suddenly aged 38. Genetic testing confirms a pathogenic KCNQ1 variant. What is the most appropriate long-term management?

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Correct answer: B — Nadolol and ICD implantation

Explanation lettering: C = shown as A · A = shown as B · B = shown as C

This patient has Long QT syndrome type 1 (LQT1, KCNQ1) with survived cardiac arrest. Per the 2022 ESC VA/SCD Guidelines, an ICD is recommended for secondary prevention (Class I). Beta-blockers (nadolol or propranolol preferred) are recommended as first-line in all LQTS patients (Class I). Mexiletine (B) is for LQT3, not LQT1. LCSD alone (C) is insufficient after cardiac arrest. Verapamil (D) is not mainstay of LQTS management. Flecainide (E) is not indicated in LQTS.

Reference: ESC (2022): Guidelines for the Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death