Energy drinks (EDs) are gaining popularity every year with a broad consumer base including athletes, amateur competitors, and even those experiencing work-related fatigue. Evidence indicates that a significant number of individuals who consume EDs experience resultant morbidity and/or mortality, with a preponderance of cases involving teenagers and young adults. Adverse effects of ED consumption may occur in healthy persons, however certain individuals may be particularly susceptible to complications. At-risk populations include those of young age, the caffeine-naï ve, or caffeine-sensitive, pregnant women, competitive athletes, and those with underlying cardiovascular disease. This paper summarizes the cardiovascular complications associated with ED use and provides suggestions on consumption of these drinks in various populations.

AIMTo investigate whether consumption of an energy drink will acutely impair endothelial function in young healthy adults.METHODSEnergy drinks are being consumed more and more worldwide, and have been associated with some deaths in adolescents and young adults, especially when consumed while exercising. After fasting and not smoking for at least 8 h prior, eleven medical students (9 males) received an electrocardiogram, blood pressure and pulse check, and underwent baseline testing (BL) of endothelial function using the technique of endothelium-dependent flow mediated dilatation (FMD) with high-resolution ultrasound (according to recommended guidelines of the University of Wisconsin Atherosclerosis Imaging Research Program Core Laboratory). The subjects then drank an energy beverage (EB), a 24-oz can of Monster Energy, and the above was repeated at 90 min after consumption. The relative FMD (%) was calculated as the ratio between the average post-cuff release and the baseline diameter. Each image was checked for quality control, and each artery diameter was measured from the media to media points by two experts, 3 measurements at the QRS complex, repeated on 3 separate beats, and then all were averaged.RESULTSSubjects characteristics averages (given with standard deviations) include: Age 24.5 ± 1.5 years, sex 9 male and 2 female, weight 71.0 ± 9.1 kg, height 176.4 ± 6.0 cm, BMI 22.8 ± 2.7 kg/m2. The hemodynamics were as follows, BL vs EB group respectively (mean ± SD): Heart rate 65.2 ± 11.3 vs 68.2 ± 11.8 beats per minute, systolic blood pressure 114.0 ± 10.4 mmHg vs 114.1 ± 10.4 mmHg, diastolic blood pressure 68.8 ± 9.3 mmHg vs 70.6 ± 7.1 mmHg; all were not significantly different. However after drinking the EB, a significantly attenuated peak FMD response was measured (mean ± SD): BL group 5.9% ± 4.6% vs EB group 1.9% ± 2.1%; P = 0.03). Given the increased consumption of energy beverages associated with exercise in young adults, more research is needed.CONCLUSIONEnergy beverage consumption has a negative impact on arterial endothelial function in young healthy adults.

We identified five independent predictors of high DFT. We propose the EF-SAGA risk score to help decision making. Primary prevention patients with an LVEF > 20% had an exceedingly low incidence of high DFT suggesting that testing could be avoided in these patients. Careful assessment of the risk-benefit ratio of testing is important in high-risk patients.

Background: Controversy exists over routine defibrillation threshold (DFT) testing during implantable cardioverter-defibrillator (ICD) placement. The aim of this study was to reevaluate risk factors for high DFT and propose a risk assessment tool. Methods: We retrospectively analyzed 1642 consecutive patients who received an ICD and underwent DFT testing. Results: The incidence of high DFT requiring addition of a subcutaneous array was 2.3%. Five significant independent variables predictive of high DFT were identified including younger age, male gender (hazard ratio 1.99), LV dysfunction, secondary prevention (hazard ratio 2.33), and amiodarone use (hazard ratio 2.39). Each 10 year increase in age was indicative of a 0.35 times lower chance of high DFT. Each 10% increase of LV EF was indicative of a 0.52 times lower chance of high DFT. These five variables form the EF-SAGA risk score (LV EF less than 20%, Secondary prevention ICD indication, Age less than 60 years, male Gender, Amiodarone use). Cumulative risk of high DFT increased incrementally; patients with four or more variables had an 8.9% likelihood of high DFT (Figure 1). Importantly, primary prevention patients with LV EF >20% had a negative predictive value for high DFT of 99.3%. Conclusions: In conclusion, we identified five independent predictors of high DFT. We propose the EF-SAGA risk score to help decision making. Primary prevention patients with an LV EF >20% had an exceedingly low incidence of high DFT suggesting that testing could be avoided in these patients. Careful assessment of the risk-benefit ratio of testing is important in high-risk patients.