Abstract

Introduction: Long QT syndrome (LQTS) is a repolarization cardiac disorder that can lead to syncope, cardiac arrest and sudden death in apparently healthy individuals. The congenital type can be accompanied with congenital sensory-neural deafness (Jervell-Lang-Nielsen syndrome). Although there are limited studies assessed the frequency of LQTS in these children in developed countries, regarding introducing the new formula, it is necessary to re-evaluate the frequency of this syndrome. Materials and Methods: This cross-sectional and descriptive study was done on 203 patients with congenital sensory-neural hearing loss (SNHL) that had cochlear implant surgery in Baqiyatallah cochlear implant center from 2008 to 2012. Corrected QT was calculated with this formula: QTC = QT 1.75 (heart rate-60) Patients with QTC > 460 ms, were categorized in four groups: Long QT: QT > 460, Borderline: 440 < QTC 460, markedly long QT: QTC > 470 and very markedly: > 500. Also, cardiac arrhythmias or arrest were evaluated in patients during cochlear implant surgery and in the postoperative recovery period. Result: Prevalence of LQTS in patients was 12.32 (25 patients). Prevalence of markedly long QT and very markedly long QT were 8.87 (18 patients) and 2.46 (5 patients) respectively. The prevalence of borderline group was 14.29 (29 patients). None of the patients during or after surgery were affected by cardiac arrhythmias or arrest. Conclusion: This study showed higher prevalence of LQTS in patients with SNHL than the normal population, and we suggest that all patients with congenital deafness should be screen for LQTS.