RESUMO
OBJECTIVE: Anorexia nervosa carries the highest mortality of any psychiatric disorder with largely attributed to a cardiovascular etiology. The aim of this study was to evaluate QT alteration and the factors to influence the QT alteration. METHODS: We evaluated a hospital cohort of patients with anorexia nervosa (n=78) and age-matched healthy women (n=89). The QT, QT dispersion and U wave were measured from electrocardiograms in both patients and controls, and QT was corrected for heart rate using Bazett's formula. We also gathered the data for serum electrolytes, cholesterol, uric acid, creatinine, thyroid hormone, and bone mineral density. RESULTS: QT dispersion was significantly greater in patients with anorexia nervosa whereas corrected QT interval did not differ between groups. U wave tended to appear more frequently in patients with anorexia nervosa. QT dispersion was influenced by lowest ever body mass index and serum thyroid hormone. CONCLUSION: QT dispersion and U wave look to be more reliable index than heart rate-corrected QT, which may reflect arrhythmia potential in patients with anorexia nervosa. Lowest ever body mass index and current metabolic status could be predictive factors to cardiac arrhythmia in anorexia nervosa. Longitudinal follow-up study to evaluate risk as well as protective factors to cardiac mortality is warranted.