QT Interval Dispersion and Resting Metabolic Rate in Chronic Anorexia Nervosa

Abstract

Objective: During the starvation phase of anorexia nervosa (AN), cardiac and skeletal muscle mass decreases, whereas electrocardiographic QT dispersion, a marker of arrhythmia risk, increases. QT dispersion during the chronic phase of AN and its relationship to resting metabolic rate (RMR) have not been described previously and is the subject of the current investigation.

Method: Six AN patients were compared with 10 age-matched control subjects. Serum electrolyte levels, electrocardiography, anthropomorphic data, and indirect calorimetry were obtained for all participants.

Results: Corrected QT interval (QTc) did not differ between groups, but QT dispersion was significantly greater in AN patients. QT dispersion correlated negatively with resting oxygen consumption and RMR. The relationship between QT dispersion and RMR did not persist after correcting for lean body mass.

Conclusions: AN patients with a low RMR may be at risk for increased QT dispersion. QT dispersion is a widely available and inexpensive measure, which may reflect both metabolic status and arrhythmia potential.