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QT interval in anorexia nervosa.

Authors :
Cooke RA
Chambers JB
Singh R
Todd GJ
Smeeton NC
Treasure J
Treasure T
Source :
British heart journal [Br Heart J] 1994 Jul; Vol. 72 (1), pp. 69-73.
Publication Year :
1994

Abstract

Objectives: To determine the incidence of a long QT interval as a marker for sudden death in patients with anorexia nervosa and to assess the effect of refeeding. To define a long QT interval by linear regression analysis and estimation of the upper limit of the confidence interval (95% CI) and to compare this with the commonly used Bazett rate correction formula.<br />Design: Prospective case control study.<br />Setting: Tertiary referral unit for eating disorders.<br />Subjects: 41 consecutive patients with anorexia nervosa admitted over an 18 month period. 28 age and sex matched normal controls.<br />Main Outcome Measures: maximum QT interval measured on 12 lead electrocardiograms.<br />Results: 43.6% of the variability in the QT interval was explained by heart rate alone (p < 0.00001) and group analysis contributed a further 5.9% (p = 0.004). In 6 (15%) patients the QT interval was above the upper limit of the 95% CI for the prediction based on the control equation (NS). Two patients died suddenly; both had a QT interval at or above the upper limit of the 95% CI. In patients who reached their target weights the QT interval was significantly shorter (median 9.8 ms; p = 0.04) relative to the upper limit of the 60% CI of the control regression line, which best discriminated between patients and controls. The median Bazett rate corrected QT interval (QTc) in patients and controls was 435 v 405 ms.s-1/2 (p = 0.0004), and before and after refeeding it was 435 v 432 ms.s1/2 (NS). In 14(34%) patients and three (11%) controls the QTc was > 440 ms.s-1/2 (p = 0.053).<br />Conclusions: The QT interval was longer in patients with anorexia nervosa than in age and sex matched controls, and there was a significant tendency to reversion to normal after refeeding. The Bazett rate correction formula overestimated the number of patients with QT prolongation and also did not show an improvement with refeeding.

Details

Language :
English
ISSN :
0007-0769
Volume :
72
Issue :
1
Database :
MEDLINE
Journal :
British heart journal
Publication Type :
Academic Journal
Accession number :
8068473
Full Text :
https://doi.org/10.1136/hrt.72.1.69