The electrocardiogram in anorexia nervosa

Abstract

Anorexia nervosa claims the highest mortality rate of all psychiatric illnesses; death is often sudden, suggesting a primary cardiac arrhythmic etiology. We analyzed the admission electrocardiograms from 67 consecutive inpatients with anorexia nervosa to determine the prevalence and clinical associations of EKG repolarization abnormalities, known to increase the likelihood of ventricular arrhythmias. QT interval prolongation was present in 20 patients (29.9%), and large U waves were present in 12 patients (17.9%). Large U waves were independently associated with serum potassium level (p = .02) but not with degree of weight loss or clinical symptoms. The corrected QT interval showed a nonsignificant trend toward association with serum potassium concentration (p = .08) but not with other variables. These findings differ from previous studies which concluded that EKG abnormalities in anorexia were secondary to weight loss.