Exposure to e-cigarette aerosols can cause cardiac arrhythmias, a study shows

Exposure to e-cigarette aerosols can cause cardiac arrhythmias, a study shows

A new study by University of Louisville researchers at the Christina Lee Brown Envirome Institute has found that exposure to e-cigarette aerosols can cause cardiac arrhythmias in animal models -; both in the form of premature and skipped heartbeats. The study results, published Oct. 25 in Nature Communications, suggest that exposure to certain chemicals in e-cigarette liquids (e-liquids) promotes arrhythmias and cardiac electrical dysfunction.

Our results show that short-term exposure to e-cigarettes can destabilize heart rhythms through certain chemicals in e-liquids. These results suggest that using e-cigarettes with certain flavors or solvents can disrupt the heart's electrical conduction and cause arrhythmias. These effects could increase the risk of atrial or ventricular fibrillation and sudden cardiac arrest.”

Alex Carll, assistant professor, UofL Department of Physiology, principal investigator

Researchers tested the cardiac effects of inhaled e-cigarette aerosols using only the two main ingredients in e-liquids (nicotine-free propylene glycol and vegetable glycerin) or from retail flavored nicotine-containing e-liquids. They found that with all e-cigarette aerosols, the animals' heart rates slowed during puff exposure and sped up afterward as heart rate variability decreased, indicating fight-or-flight stress responses. Additionally, e-cigarette puffs made from a menthol-flavored e-liquid or propylene glycol alone caused ventricular arrhythmias and other conduction irregularities in the heart.

This work, conducted in collaboration with Daniel Conklin and Aruni Bhatnagar, professors in the UofL Department of Environmental Medicine, adds to a growing body of research on the potential toxicities and health effects of e-cigarettes reported by the American Heart Association Tobacco Regulation and Addiction Center, for which UofL is a flagship institute functions.

"The results of this study are important because they provide new evidence that e-cigarette use could disrupt normal heart rhythms - something we didn't know before," Bhatnagar said. “This is extremely worrying given the rapid increase in e-cigarette use, particularly among young people.”

As e-cigarette use has increased nationwide, the potential benefits and harms of vaping have been discussed. Because vaping does not involve combustion, it exposes users and bystanders to little or no carbon monoxide, tar, or cancer-causing nitrosamines compared to traditional cigarettes. However, e-cigarettes can release aldehydes, particulate matter, and nicotine in comparable amounts to combustible cigarettes. Vaping could help smokers quit combustible cigarettes, but the appeal and addictiveness of e-cigarettes may encourage teens to vape or start smoking amid unknown long-term risks. More than 25% of high school students and 10% of middle school students in the U.S. reported using e-cigarettes before the pandemic.

Additional research by Carll and Matthew Nystoriak, an associate professor of medicine at UofL, to determine the effects of vape flavors on the heart recently received $3.6 million in research funding from the National Institutes of Health.

"Our team's findings that certain ingredients in e-cigarette liquids promote arrhythmias indicate that more research into the cardiac effects of these components in both animals and humans is urgently needed," Carll said.

Source:

University of Louisville

Reference:

Carll, AP, et al. (2022) E-cigarettes and their sole components induce cardiac arrhythmias and conduction abnormalities in mice. Nature communication. doi.org/10.1038/s41467-022-33203-1.

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