RESUMO
AIMS: Energy Drink (ED)-associated cardiovascular emergency visits have increased in recent years. Although a toxicity threshold has been established for caffeine, the safety profile of whole ED consumption has not yet been defined. METHODS: This systematic review was conducted following the PRISMA guidelines. Three reviewers conducted two separate systematic searches on PubMed on October 24 and December 3, 2019. Out of 250 potential records, 43 prospective clinical studies assessing the effects of ED on heart rate (HR) and/or any electrocardiographic (ECG) parameters were included. A meta-analysis was conducted to estimate pooled p-values using metap command for STATA 10.0. RESULTS: After ED consumption, resting HR increased in 71.1% of studies (pooled p-value <0.001) but was only significant in 38%; HR during and after exercise increased in 55.5% (pooled p-value <0.001) and 71.4% of studies, respectively; QRS increased in all but two protocols; evidence on PR interval was contradictory, and corrected QT interval (QTc) increased compared to baseline in all but one study, exceeding the pathological limit value in two of them. T wave changes were seen in two studies, and one study reported a ratio of 5 to 1 in the number of ectopic beats. CONCLUSION: Acute consumption of ED can alter the ECG in certain risk populations, posing a risk whose magnitude is yet to be determined. Caution should be exercised among at-risk and underage individuals but further research in these populations is warranted before restrictions are made.