A recent study has observed a disturbing increase in QTc after normal subjects consumed large volumes of two different energy drinks.1 While small QTc changes in healthy volunteers are not a clinical concern, there can be extreme danger for patients with congenital long QT syndrome or patients who are taking any of the 171 medicines that prolong QTc (see https://crediblemeds.org/druglist ). Fourteen drugs that produced small QTc changes in normal subjects have been removed from the market because, when they were taken by thousands of people, an alarming number of deaths were reported to the FDA. For energy drinks, at least 34 deaths attributed to their consumption have been reported to the FDA and cases of torsades de pointes (TdP) arrhythmia have been seen in patients with congenital long QT syndrome.2
Since these energy drinks are so ubiquitous and their potential harm is often unpredictable, physicians and other healthcare providers should warn their patients and the public of this risk, especially for patients with congenital long QT syndrome.
1. Shah SA, Szeto AH, Farewell R, et al. Impact of High Volume Energy Drink Consumption on Electrocardiographic and Blood Pressure Parameters: A Randomized Trial. J Am Heart Assoc 2019;8:e011318.
2. Winniford MD. Energy Drinks: Another Cause of QT Prolongation? J Am Heart Assoc 2019;8:e012833.