Cardiovascular and Autonomic Responses to Energy Drinks-Clinical Implications.

There is an increasing consumption of energy drinks both in the United States and worldwide. The components of these beverages are sometimes unclear but commonly include caffeine, sugars, taurine, and B-vitamins. Young people, particularly those engaged in sports, studying, and in the military are especially likely to be consumers of energy drinks. While limited data are available regarding their autonomic and hemodynamic effects, current literature suggests that energy drink consumption is accompanied by increases in blood pressure, sympathetic drive, and also in QT prolongation. There are no systematic long term studies identifying consequences of frequent energy drink consumption. However, multiple anecdotal reports implicate energy drinks in adverse cardiovascular events including atrial fibrillation, ventricular arrhythmia, myocardial infarction, and sudden death. Events such as atrial fibrillation may even occur in otherwise healthy subjects with structurally normal hearts. It is likely that these cardiovascular outcomes are triggered by the hemodynamic, autonomic, and electrocardiographic responses to energy drink consumption. What remains unclear is how concomitant use of other stimulants such as amphetamines and nicotine may interact to potentiate neural and circulatory responses and cardiovascular consequences when combined with energy drinks.

Takotsubo cardiomyopathy associated with titration of duloxetine.

Takotsubo cardiomyopathy is characterized by transient multisegmental left ventricular dysfunction, dynamic electrocardiographic changes that mimic acute myocardial infarction, and the absence of obstructive coronary disease. Takotsubo cardiomyopathy has been solidly associated with antecedent emotional and physical stressors that trigger catecholamine surges, which lead to coronary vasospasm or direct myocardial injury. Some medications can also cause catecholamine surges, although this phenomenon is not as well described. Duloxetine is a combined serotonin and norepinephrine reuptake inhibitor (SNRI). The basic goal of SNRIs is to increase catecholamine levels in neuronal tissue. However, the increased catecholamine levels may also affect the cardiovascular system.Herein, we report the case of a 59-year-old woman whose takotsubo cardiomyopathy was temporally associated with the titration of duloxetine. The duloxetine therapy was subsequently discontinued, and the patient's left ventricular function recovered completely 1 month after the index event. The purpose of this report is to alert clinicians to a possible association between SNRI medications and takotsubo cardiomyopathy.