Electrocardiographic QTc as a Surrogate Measure of Cardiac Risk in Children, Adolescents, and Young Adults With Eating Disorders

The study goal was to investigate electrocardiographic findings, including corrected QT interval (QTc), in patients aged 8 to 23 with eating disorders (EDs) at presentation, compared with an age-and sex-matched control population. We retrospectively reviewed 200 ED patients, and 200 controls. Blinded electrocardiograms (ECGs) were interpreted by an expert reader, and QT intervals corrected using the Bazett formula. Eating disorder patients were 89.5% female, with mean age 16.4 years and median percent median body mass index (BMI)-for-age (%mBMI)a of 91.1%. In ED patients, QTc was significantly shorter than controls (399.6 vs 415.0msec, P < .001). After adjusting for height, %mBMI, sex, magnesium level, and bradycardia, mean QTc duration in patients with anorexia nervosa-restricting subtype (AN-R) was significantly shorter than other ED patients (P = .010). Higher %mBMI was associated with shorter QTc duration (P = .041) after adjusting for height, magnesium, bradycardia, and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnosis. Within the ED group, no significant association was identified between QTc and medications, electrolytes, or inpatient status.