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

Characterization of Myocardial Repolarization Reserve in Adolescent Females With Anorexia Nervosa

“…It is therefore likely that QT/RR slope is a more sensitive measure of myocardial repolarization dynamics than simply measuring absolute QT interval or changes at peak exercise. Previous studies have found BMI to be a significant predictor of QTc duration; 9 however, this correlation is not a universal finding, 32 and other studies only detect a correlation with QT dispersion and LV mass index. 47 Certainly BMI is a guide to the severity of malnutrition, although it is imperfect, and because QT duration is affected by so many factors, the association between BMI and QT may not always be readily apparent, particularly in the context of moderate or minor reductions in BMI.…”

“…[29][30][31] Importantly, QT prolongation also occurs in AN as a result of the dysautonomia that characterizes the condition. 7,[32][33][34] Prolongation of the QTc occurs in various forms of autonomic failure including diabetic autonomic neuropathy, 35 familial dysautonomia, 36 and primary autonomic failure, 37 and, similarly, nonselective pharmacological autonomic blockade causes dose-dependent QTc prolongation. 38 Failure to adapt the QT interval in response to changes in sympathetic innervation explains the occurrence of malignant arrhythmias in congenital LQTS.…”

“…47 Certainly BMI is a guide to the severity of malnutrition, although it is imperfect, and because QT duration is affected by so many factors, the association between BMI and QT may not always be readily apparent, particularly in the context of moderate or minor reductions in BMI. Although QT prolongation in AN is largely reversible with appropriate nutrition, 4,5,32,33 overt autonomic dysfunction (and possibly impaired repolarization reserve) may persist for several years despite adequate refeeding and relative normalization of the BMI. 48 Indeed, the highest BMI tertile among patients was of comparable body mass to the control group as a whole; however, despite this, the QT/RR slope was still more gradual in the patients.…”

Cardiovascular Complications in Eating Disorders

“…Considering the subtypes of anorexia nervosa, a significant increase has been found in weight/height ratio and body mass index from malnourished stage to weight restoration, paralleled by a significant decrease in QTd among anorectic patients (restricting type) (Nahshoni, et al, 2007). With respect to bulimia nervosa, compared with the controls, bulimic patients with a history of anorexia nervosa seem to have significantly more signalaveraged electrocardiography abnormalities (Takimoto et al, 2006).…”

Risk for prolonged QT interval and associated outcomes in children with early restrictive eating patterns

“…Prolongation of the QT interval, a marker of abnormal ventricular re-polarisation, has been considered a potential factor in the underlying mechanism of sudden cardiac death in these patients. [5][6][7][8][9] Controversy remains, however, as to the utility of corrected QT (QTc) measurement as a proxy to disease severity and risk of cardiac death, as studies to date have been unable to consistently correlate a QTc threshold with disease progression. 3,8,10,11 Although it has been described that some patients with eating disorders can experience electrolyte abnormalities and loss of cardiac muscle mass, 5,12 whether these factors are directly associated with QTc prolongation or malignant arrhythmias has not been well-demonstrated.…”