No QTc Prolongation in Girls and Women with Turner Syndrome.

Context: Turner syndrome (TS) is a genetic condition that is reported to be associated with a prolonged rate-corrected QT (QTc) interval.

Objectives: To evaluate the prevalence of QTc prolongation in patients with TS, to compare their QTc intervals with healthy controls, and to investigate whether QTc prolongation is associated with a monosomy 45,X karyotype.

Method: Girls (n = 101) and women (n = 251) with TS visiting our center from 2004-2018 were included in this cross-sectional study. QT intervals of 12-leaded electrocardiograms were measured manually, using Bazett's and Hodges formulas to correct for heart rate. A QTc interval of >450 ms for girls and >460 ms for women was considered prolonged. Corrected QT (QTc) intervals of patients with TS were compared to the QTc intervals of healthy girls and women from the same age groups derived from the literature.

Results: In total, 5% of the population with TS had a prolonged QTc interval using Bazett's formula and 0% using Hodges formula. Mean QTc intervals of these patients were not prolonged compared with the QTc interval of healthy individuals from the literature. Girls showed shorter mean QTc intervals compared with women. We found no association between monosomy 45,X and prolongation of the QTc interval.

Conclusions: This study shows that the QTc interval in girls and women with TS is not prolonged compared with the general population derived from the literature, using both Bazett's and Hodges formulas. Furthermore, girls show shorter QTc intervals compared with women, and a monosomy 45,X karyotype is not associated with QTc prolongation.