Low-Energy Diets and Prolonged QT Intervals-Reply

Abstract

In Reply.— The letter by Frank et al is appreciated. It highlights a somewhat unsettled area regarding the complex relationship between obesity, rapid-weight-reduction diets, QT-interval prolongation, and unexpected sudden death. Several articles have been published that have documented the occurrence of sudden cardiac death in obese persons on very-low-energy liquid protein diets. 1-4 In ten of the 17 deaths reported, electrocardiograms were recorded during the period of dieting. Nine (90%) of these ten patients had unequivocal QT prolongation, with a QT c of greater than 0.45 s. In the population study referenced by Frank et al, 5 a QT c of greater than 0.45 s occurred in only 1.7% of their obese patients. The available scientific data indicate that very-low-energy diets can be deadly, especially in a subset of patients who develop QT prolongation during rapid weight loss. The hypothesis that rapid weight loss results in acquired QT prolongation with