In another strike against electronic cigarettes, a new mouse study has found that they can cause an irregular heartbeat, also called a cardiac arrhythmia.

Researchers from the University of Louisville’s Christina Lee Brown Envirome Institute, in Kentucky, found that exposure to the aerosols from e-cigarettes could cause heart arrhythmias in animals. These included both premature and skipped heartbeats.

“Our findings demonstrate that short-term exposure to e-cigarettes can destabilize heart rhythm through specific chemicals within e-liquids,” said study author Alex Carll, an assistant professor at the institute. “These findings suggest that e-cigarette use involving certain flavors or solvent vehicles may disrupt the heart’s electrical conduction and provoke arrhythmias. These effects could increase the risk for atrial or ventricular fibrillation and sudden cardiac arrest.”

The animals’ heart rates slowed during puff exposures. They sped up afterwards, which indicated fight-or-flight stress responses. This happened when testing the main two ingredients in e-liquids (nicotine-free propylene glycol and vegetable glycerin), and flavored retail e-liquids containing nicotine. It is important to note that findings in animal research do not always pan out in humans.

“The findings of this study are important because they provide fresh evidence that the use of e-cigarettes could interfere with normal heart rhythms — something we did not know before,” said Aruni Bhatnagar, a professor in the University of Louisville’s division of environmental medicine. “This is highly concerning, given the rapid growth of e-cigarette use, particularly among young people.”

While vaping does not involve combustion, thus exposing users and bystanders to little if any carbon monoxide, tar or cancer-causing nitrosamines, these e-cigarettes can deliver aldehydes, particles and nicotine at levels comparable to conventional cigarettes.

Among the pros are that vaping may help people quit traditional cigarettes. However, the appeal and addictiveness of e-cigarettes may encourage youth to start smoking, like the more than 25% of U.S. high schoolers and 10% of middle schoolers who reported using e-cigarettes before the pandemic.

Carll and Matthew Nystoriak, an associate professor of medicine at the University of Louisville, have received 3.6 million in research funding from the U.S. National Institutes of Health to determine the effects of vape flavorings on the heart.

“Our team’s findings that specific ingredients in e-cigarette liquids promote arrhythmias indicates there is an urgent need for more research into the cardiac effects of these components in both animals and humans,” Carll said in a university news release.

The findings were published online Oct. 25 in Nature Communications.

More information

The U.S. Centers for Disease Control and Prevention has more on e-cigarettes.

SOURCE: University of Louisville, news release, Oct. 25, 2022

Source: HealthDay