Sodium channel blockers in the management of long QT syndrome types 3 and 2: A system review and meta‐analysis

Background β‐Blockers are first‐line therapy in patients with long QT syndrome (LQTS). However, β‐blockers had genotype dependent efficacy (LQT1>LQT2>LQT3). Sodium channel blockers have been recommended as add‐on therapy for LQT3 patients. However, the pooled effect of sodium channel blockers in all LQTS patients remains unknown. Methods We conducted a systematic electronic search of PubMed, Embase, and the Cochrane Library. Fixed effects model was used to assess the effect of sodium channel blockers on QTc, cardiac events (CEs), and the proportion of QTc ≥ 500 ms and QTc ≤ 460 ms in LQTS patients. Results Pooled analysis of 14 studies with 213 LQTS (9 LQT1 + 63 LQT2 + 135 LQT3 + 6 others) patients showed that sodium channel blockers significantly shortened QTc by nearly 50 ms (mean difference [MD], −49.43; 95% confidence interval [CI], −57.80 to −41.05, p