Smoking is the most preventable risk factor for heart and lung disease and is expected to cause one billion deaths in the 21st century. Electronic cigarettes have been sold in recent years as a safer smoking habit, with millions of people already using it around the world.
Electronic cigarettes simulate the effect of smoking on the production of inhaled vapor. The device consists of a battery, a cartridge containing liquid and the heating element is heated and vaporized liquid. Laboratory analysis of liquids shows that they are less toxic than regular cigarettes. Most studies found no nitrosamines, but even in the studies that have been detected nitrosamines levels were detected 500-1400 times less than the amount present in a tobacco cigarette. This means that electronic cigarettes should be used daily for 4-12 months to get the amount of nitrosamines found in one cigarette tobacco.
Since heart disease is the leading cause of morbidity and mortality among smokers, with 40% of deaths in smokers due to ischemic heart disease alone, the research team decided to conduct the first clinical study of acute effects of electronic cigarettes on the function of the heart. They decided to compare their results with the acute effects of conventional cigarettes on cardiac function, as electronic cigarettes are sold only for smokers, as an alternative to the habit.
Previous studies of the research group and others have shown that acute inhalation smoking causes significant defects in myocardial function. This means that sub clinical dysfunction already present in healthy asymptomatic young people who smoke tobacco cigarettes. The aim was to assess the extent to which these symptoms appear similar preclinical population after using electronic cigarettes.
The researchers measured myocardial function in 20 healthy young daily smokers aged 25-45 years before and after smoking one cigarette tobacco and 22 daily users of e-cigarettes the same age before and after using the device for 7 minutes.
Experienced users of electronic cigarettes have been studied, since they use the device more rapidly than the first time users. Although both groups were equal age, users of electronic cigarettes was 44% higher lifetime exposure to tobacco smoking than smokers.
Electronic cigarette, commercially available liquid nicotine concentration 11mg/ml was used (NOBACCO USA Mix). This has been tested by independent laboratory toxicology and found not to contain nitrosamines and polycyclic aromatic hydrocarbons.
Myocardial function was investigated using cardiac ultrasound (echocardiogram) and homodynamic measurements (blood pressure and heart rate).
The researchers found that smoking one cigarette tobacco resulted in significant acute myocardial dysfunction, but electronic cigarettes no acute adverse effects on cardiac function. Smoking tobacco cigarettes were important homodynamic consequences, with a significant increase in systolic and diastolic blood pressure and heart rate. Unlike electronic cigarettes are produced only a slight increase in diastolic blood pressure. Dr. Farsalinos said: “This indicates that although nicotine is present in the liquid used (11mg/ml), it is absorbed at a lower cost than conventional cigarette smoking.”