QT Interval and QT Dispersion in Eating Disorders

Abstract

Background: Eating disorders are thought to be risk factors for cardiac sudden death secondary to arrhythmia. Results in previous studies on QT interval and QT dispersion, markers of fatal arrhythmia, have been inconsistent. Methods: We prospectively examined 179 female eating disorder patients, being over 18 years old and diagnosed according to the DSM-IV criteria between January 1995 and December 2002, and 52 healthy women. Patients with abnormal plasma electrolytes or taking medications that might influence the electrocardiogram (ECG) were excluded from the study. QT intervals were corrected for heart rate using Bazett’s formula and the nomogram method, which is more reliable at extremely low heart rates than Bazett’s formula. QT dispersion was measured as the difference between the longest and shortest QT intervals. QT intervals and QT dispersion in each patient group were compared with those in the control group. Results: The 164 eligible patients consisted of 43 patients with anorexia nervosa restricting type, 35 with anorexia nervosa binge eating/purging type, 63 with bulimia nervosa purging type, and 23 with bulimia nervosa nonpurging type. There was no significant difference in age between eating disorder patients and controls. QT interval and QT dispersion were significantly longer in all eating disorder subtypes than in the control group. QT interval and QT dispersion were significantly correlated with the rate of body weight loss in bulimia nervosa. Conclusions: QT interval and QT dispersion were prolonged in both anorexia nervosa and bulimia nervosa. Examination of ECG in eating disorder patients without extremely low body weight also appears to be clinically important.

Alterations in QT dispersion in the surface electrocardiogram of female adolescents diagnosed with restricting-type anorexia nervosa

“…Whereas some studies [2,10,11] similar to ours found that QT interval and QTd are greater in emaciated AN patients than in normal controls, others [12,17] found normal QT interval, QTc, and QTd in underweight AN patients. Differences among these studies may reflect differences in participants' gender and age, psychiatric comorbidity, and use of medications.…”

“…Several studies [2,10,11], although not all [12], found that QT interval and QTd are greater in AN female patients than in non-eating-disorder controls, with the QTd in these patients being inversely correlated with left ventricular mass [10]. A significant decrease in QTd may occur following weight restoration [12].…”

Heart rate variability as a measure of cardiac autonomic function in anorexia nervosa: A review of the literature

“…For example, patients with anorexia nervosa (AN) are typically bradycardic (resting heart rate (HR) less than 50 per minute) and have relatively low arterial blood pressure (usually lower than 100/50 mm Hg) (Casper, 1986;Kalager, Brubakk, & Bassoe, 1978). Among others, cardiovascular abnormalities reported include QT-interval prolongation (Lesinskiene, Barkus, Ranceva, & Dembinskas, 2008;Takimoto et al, 2004), voltage decrease, T-wave inversion, weight reduction and thinning of the left ventricle, and drop of heart functional parameters (ejection fraction, minute blood volume) (Casiero & Frishman, 2006;Olivares et al, 2005). The origin and pathogenesis of such changes are not absolutely clear, though many authors (Casper, 1986;Fohlin, 1977) regard them as an adaptation to poor nutrition.…”

QT Interval and Dispersion in Very Young Children Treated with Antipsychotic Drugs: A Retrospective Chart Review

“…Increased QTd was also reported for social anxiety disorder, pointing toward cardiac ANS imbalance (Nahshoni et al, 2004c). Recently, QTd analysis has been used in eating disorders and might show promise as a noninvasive measure for cardiac risk in anorectic patients (Takimoto et al, 2004). QTd analysis has also been recently used in an effort to evaluate the cardiotoxic effects of neuroleptics.…”