title: Prolongation of the cardiac QTc interval in Turner syndrome.
abstract: Anatomic anomalies of the cardiovascular system occur in approximately 50% of individuals with Turner syndrome (TS), with the specific genetic cause(s) for the heart defects still unknown. Because congenital heart disease may be associated with conduction system abnormalities, we compared electrocardiograms (ECGs) in 100 women with TS and 100 age-matched female controls. Women with TS were significantly more likely to demonstrate left posterior fascicular block (p < 0.005), accelerated AV conduction (p < 0.006), and T wave abnormalities (p < 0.006). The PR interval was significantly shorter (137 +/- 17 vs. 158 +/- 18 ms, p < 0.0001) and the rate-corrected QT interval (QTc) significantly longer in women with TS than in controls (423 +/- 19 ms vs. 397 +/- 18 ms; p < 0.0001). Twenty-one women with TS but no controls had a QTc greater than 440 ms. We found no statistically significant relation between body habitus, cardiac dimensions, evidence of congenital heart disease, or metabolic parameters and the incidence of ECG abnormalities or QTc duration in TS. Cardiac conduction and repolarization abnormalities appear to be intrinsic features of TS, suggesting that deletion of the second sex chromosome has more profound effects on the cardiovascular system than previously recognized, and that ECG analysis should be included in evaluating and monitoring patients with Turner syndrome.
authors.affiliation: From Developmental Endocrinology Branch (CAB, PLV, VKB), National Institute of Child Health & Human Development; National Heart, Lung and Blood Institute (VS, CAM, DRR); Diagnostic Radiology Department (VBH), Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland; and Department of Radiology (VBH), Uniformed Services University of the Health Sciences, Bethesda, Maryland.
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Bondy
authors.forename: Phillip L
authors.initials: PL
authors.lastname: Van
authors.forename: Vladimir K
authors.initials: VK
authors.lastname: Bakalov
authors.forename: Vandana
authors.initials: V
authors.lastname: Sachdev
authors.forename: Carol A
authors.initials: CA
authors.lastname: Malone
authors.forename: Vincent B
authors.initials: VB
authors.lastname: Ho
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Rosing
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure; D001827:Body Height; D015992:Body Mass Index; D018376:Cardiovascular Abnormalities / Q000235:genetics / Q000503:physiopathology; D016022:Case-Control Studies; D002648:Child; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D005260:Female; D006321:Heart / Q000502:physiology / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008875:Middle Aged; D014424:Turner Syndrome / Q000235:genetics / Q000503:physiopathology*