Electronic cigarettes used by smokers who want to kick the habit show no connection to heart disease, according to a study that adds to evidence of health benefits of switching from tobacco to smokeless alternatives.

E-cigarettes, electronic tubes that simulate the effect of smoking by producing nicotine vapor, prompted no adverse effects on cardiac function in the study, researchers from the Athens- based Onassis Cardiac Surgery Center said in a report presented at the European Society of Cardiology annual meeting in Munich today.

Investigators examined the heart activity of 20 young daily smokers after one ordinary cigarette against 22 people who smoked an electronic cigarette for 7 minutes. Whereas tobacco smokers showed ''significant'' disruptions of functions such as heartbeats or blood pressure, the effect of e-cigarettes on the heart was minimal, Konstantinos Farsalinos, one of the researchers, said in the presentation.

''Currently available data suggest that electronic cigarettes are far less harmful, and substituting tobacco with electronic cigarettes may be beneficial to health,'' Farsalinos said.

Previous studies have found that the electronic devices would have to be smoked daily for four to 12 months to achieve the levels of nitrosamines, a carcinogen, that are present in a single tobacco cigarette, the researchers said. Industrywide e- cigarette sales this year are likely to double from $250 million in 2011, according to UBS AG.

Psychological Effects

Electronic cigarettes, which mimic the look and feel of traditional versions without generating smoke and ash, are one of the few smoking alternatives that provide users with their chemical need for nicotine and reproduce the psychological effect of holding and smoking a cigarette, the researcher said.

Makers of the battery-powered devices include Lorillard Inc. (LO), a Greensboro, North Carolina-based producer of standard cigarettes, which acquired Blue Ecigs for $135 million in April. The U.S. Food and Drug Administration has yet to impose rules on the testing and production of e-cigarettes.

About 2.5 million people use e-cigarettes in the U.S., according to an estimate by the Tobacco Vapor Electronic Cigarette Association.

Although nicotine is present in the devices' vapor, it is absorbed by the blood at a far slower rate than tobacco smoke, accounting for the lower levels of toxicity, Farsalinos said. No traces of nitrosamine were found in the e-cigarettes in the study, he said.

To contact the reporter on this story: Mehreen Khan in London at mkhan108@bloomberg.net

To contact the editor responsible for this story: Phil Serafino at pserafino@bloomberg.net