But regardless of how the nicotine is delivered — whether through e-cigs or conventional cigarettes — it still has effects on the body. The drug is a cardiovascular stimulant, and can potentially worsen heart disease in people who already have severe heart conditions. However, it's not known whether nicotine alone can cause heart disease in people who don't have heart problems, said Dr. Michael Siegel, a tobacco researcher and professor of community health sciences at the Boston University School of Public Health.
But there's some evidence that e-cigarettes can have a substantial effect on blood vessels, and may increase people's heart attack risk in that way, Glantz said....
Studies evaluating whether e-cigarettes are less harmful than cigarettes have been inconclusive, according to a review of studies published in the journal Tobacco Control in May 2014.
Moreover, the long-term health effects in people who get nicotine in a vaporized form over time are not known, Siegel said. It's also unclear whether propylene glycol, a known irritant to the respiratory tract, could result in lung problems after decades of vaping, he said.And since that article, you might care to read this one:
And because e-cigarettes have been on the market for only about 10 years, there have been no long-term studies of people who have used them for 30 to 40 years. Therefore, the full extent of e-cigs' effects on heart and lung health, as well as their cancer-causing potential, over time is not known, Glantz told Live Science.
Electronic cigarettes may increase the risk of heart disease, researchers at UCLA report.
The team found that two risk factors for heart disease were elevated in 16 e-cigarette users compared with 18 nonsmokers.
And this one:
Our findings indicate that Electronic cigarette use, when adjusted for other risk factors, is associated with a 42 % increased odds of myocardial infarction. This increase in odds is consistent regardless of traditional cigarette smoking history. More studies are needed to further assess this risk.You can thank me later...