Acute Effects of Simultaneous Energy Drink and Alcohol Consumption on ECG Parameters in Young Healthy Adults: A Randomized Prospective Placebo-Controlled Trial

All articles of this category (opens in new window) Background: Energy drinks (ED) are a popular beverage choice and often consumed in combination with alcohol. Both ED and alcohol are known to be triggers for ECG changes and arrhythmias, that is, atrial fibrillation, QTc-prolongation, and even sudden cardiac death. However, only limited data on the effect of their simultaneous consumption is available. The aim of this study was to determine the acute effect of simultaneous ED and alcohol consumption on ECG parameters. Methods: In this randomized, double-blind, placebo-controlled, crossover trial, 40 healthy participants (mean age: 22.47 ± 2.37 years, 16 male) consumed either 750 mL of ED (containing 232 mg of caffeine) or a placebo (750 mL lemonade), both mixed with 120 mL of vodka. All ECG parameters were recorded at baseline, and 30-, 60-, 120-, and 240 minutes after consumption. Results: The heart rate (HR) increased over the study course but was significantly lower in the ED-group at 30- and 60 minutes (baseline: ED: 65.3 ± 14.8 bpm; Placebo: 66.9 ± 13.5 bpm, 30-minute: ED: 69.2 ± 14.3 bpm; Placebo: 72.0 ± 14.8 bpm; p = 0.048, 60-minute: ED: 75.9 ± 13.2 bpm; Placebo: 79.6 ± 16.2 bpm; p = 0.032). Interestingly, the PQ-interval raised in both groups postconsumption despite an increase in the heart rate (ED: baseline: 147 ± 22.1 ms, 30-minute: 153 ± 24.7 ms; Placebo: baseline: 146 ± 24.2 ms, 30-minute: 156 ± 27.6 ms). QTc time interval in the ED group was significantly lower at time point 30 minutes (ED: 408.0 ± 17.7 ms; Placebo: 418.0 ± 26.1 ms; p = 0.024). Interestingly, QTc intervals converged over the course of the observation period and were longer in the ED group after 240 minutes, although the difference was not statistically significant. Conclusion: The results of this study showed no immediate arrhythmias or health concerns regarding ECG abnormalities. While minor but significant changes in HR, PQ-, and QTc-intervals were observed shortly after intake, no sustained adverse effects occurred. Notably, the trend of the PQ-Interval during the measurement period exhibited opposite trends in the two groups. However, the amount of beverage consumed was relatively small, and only study participants with no preexisting health conditions were examined. Caution is advised when generalizing these results to individuals with preexisting cardiovascular conditions or in settings involving repeated or excessive consumption. Further research is needed to explore long-term effects and interactions in vulnerable populations or higher alcohol doses. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany