Assessment of ventricular repolarization in a large group of children with early onset deafness.

This study examined the ECG traces of 397 deaf children (age 12.5 +/- 2.9 years, range 6-19 years), after exclusion of cases with Jervell and Lange-Nielsen syndrome (JLNS), and compared them to those of 361 normal hearing counterparts (age 12.5 +/- 2.7 years; range 7-18 years). An observer, who was unaware of the hearing status of the subjects, measured QT and QTc intervals and calculated dispersions of QT and QTc from standard 12-lead ECGs recorded at a speed of 25 mm/s at rest. Although the mean QT was found to be longer in deaf children than that observed in the control group (P < 0.0001), the mean QTc was significantly shorter (P < 0.0001). The mean heart rate was significantly lower in deaf children. When QT and QTc data were recompared after the children were grouped according to the heart rate, the observed difference became less significant or disappeared. In conclusion, there are no major abnormalities for repolarization parameters in children with congenital sensorineural deafness, when compared to hearing counterparts, if heart rates are similar. Based on these results, routine ECG screening of deaf children for repolarization abnormalities may be unnecessary unless they have a history of syncope or positive family history of syncope and/or early sudden death.