The researchers noted the study’s weaknesses. At the study’s conclusion, the team performed various tests to assess the electrical and physical qualities of the hearts.
Study: According to a mouse study, e-cigarettes and marijuana may have the same damaging effects on the heart as tobacco cigarettes, opening the door to irregular cardiac rhythms.
According to experts, e-cigarettes and heated tobacco products have grown in popularity because the public views them as less dangerous than smoking.
Similarly, legal recreational marijuana has grown in popularity recently, and the public widely sees it as safer than smoking tobacco.
“We discovered that cigarettes, e-cigarettes, and marijuana significantly interfere with the electrical activity, structure, and neurological regulation of the heart,” said Huiliang Qiu, a postdoctoral scholar at the University of California, San Francisco (UCSF) in the United States.
The study, published in the journal Heart Rhythm, exposed rats to smoke, aerosol from a popular e-cigarette, aerosol from a heated tobacco product, smoke from marijuana, and smoke from modified marijuana that lacks all cannabinoids for eight weeks, compared to merely air.
The rats were exposed to a single session of actual smoking/vaping by inhaling the smoke or aerosol for five seconds twice in five minutes, with clean air in between.
This was done once every five days and once every week for eight weeks. According to the researchers, cardiac function in rats exposed to the products (but not air) deteriorated throughout that period, and blood pressure rose.
The researchers performed different tests at the end of the study to assess the electrical and physical qualities of the hearts.
The researchers discovered that all of the items caused increased scarring in the heart, a decrease in the number of blood vessels, a change in the type of nerves located in the heart, a decrease in the essential ability to adjust heart rate, and an increased risk of having arrhythmias.
“Notably, all of these tobacco and marijuana products had similar effects,” said senior author and UCSF professor of cardiology Matthew Springer.
“What’s striking about this is that it was produced by a single actual smoking/vaping session per day,” Springer said.
The researchers noted the study’s weaknesses.
“While rats are a decent model for many human cardiovascular effects, there are still variances, and one cannot draw definite conclusions about human effects from rat studies alone,” Springer explained.
However, he added that the findings are consistent with many publications in the medical literature about heart rhythm irregularities in e-cigarette or marijuana users.
Despite differences in nicotine or cannabis concentration, the researchers believe that detecting numerous physical problems in the heart, such as scarring and nerve alterations, implies a proximate cause.