Key result
High-risk features in pediatric LQTS are linked to an ~8-fold higher risk of life-threatening events.
Why the study?
Most studies on long QT syndrome have focused on Western populations, leaving limited data from Asian countries.
Cohort (n=202)
Yes
In Korean pediatric patients with LQTS, LQT2/3 genotypes, fetal arrhythmia, and QTc ≥500 ms are independent risk factors for life-threatening arrhythmic events, while nadolol or propranolol therapy is protective.
May guide closer monitoring in high-risk pediatric LQTS; leaves open optimal management pending prospective validation.
Most studies on long QT syndrome (LQTS) have been conducted in Western populations, with limited data from Asian countries. We aimed to investigate the clinical characteristics, outcomes, and risk factors for arrhythmic events in Korean pediatric patients with LQTS. We conducted a retrospective multicenter cohort study of 202 pediatric patients with LQTS. Risk factors for life-threatening arrhythmic events (LAEs) and breakthrough cardiac events (BCEs) were analyzed. The mean age at diagnosis was 8.2±5.6 years. Among 179 patients who underwent genetic testing, 72% carried pathogenic variants—most commonly LQT1 (35%), followed by LQT2 (15%) and LQT3 (8%). Independent risk factors for lifetime LAEs included LQT2 and LQT3 (vs. LQT1, hazard ratio [HR], 5.5; 95% confidence interval [CI], 2.08–14.68; and HR, 8.38; 95% CI, 2.79–25.19; respectively), fetal arrhythmia (HR, 14.8), QTc ≥500 ms (HR, 2.6), and propranolol or nadolol (HR, 0.25). BCEs occurred in 29% of patients; female sex, prior arrhythmic syncope or seizure, and QTc ≥500 ms were identified as risk factors. Pathogenic KCNQ1 S6-segment variants were associated with a higher risk of LAEs than other LQT1, LQT2, and LQT3 genotypes (HR, 26.8). This multicenter Korean cohort demonstrates genotype–phenotype patterns and highlights the contribution of fetal arrhythmia, female sex, QTc, and beta-blocker use to arrhythmic risk stratification in pediatric LQTS. These results support early diagnosis and genotype- and phenotype-guided management and highlight the need for international studies to refine risk stratification in diverse populations.
No takes yet. Share an insight, caveat, or question.
Song et al. (2026) conducted a cohort in Long QT syndrome (LQTS) (n=202). LQT3 genotype vs. LQT1 genotype was evaluated on Lifetime life-threatening arrhythmic events (LAEs) (HR 8.38, 95% CI 2.79-25.19, p=<0.001). In pediatric patients with long QT syndrome, LQT2 and LQT3 genotypes, fetal arrhythmia, and QTc ≥500 ms independently increased the risk of life-threatening arrhythmic events.
Synapse has enriched 5 related papers. Consider them for comparative context: