Smoking Effects on Ventricular Repolarization

We know that smoking increases the risk of sudden cardiac death, which is linked to changes in ventricular repolarization. Is there a difference in sudden cardiac death risk between smoking tobacco cigarettes vs. e-cigarettes? Associate Editor Nisha Charkoudian (U.S. Army Research Institute for Environmental Medicine) interviews lead author Holly Middlekauff (University of California Los Angeles) and content expert Marmar Vaseghi (University of California Los Angeles) about the new study by Ip et al. In this study, the authors compared electrocardiogram indices of ventricular repolarization in tobacco smokers before and after smoking a tobacco cigarette, as well as e-cigarette vapers before and after smoking an e-cigarette—once with and once without nicotine. Acute nicotine intake was the same among both types of smokers. However, three ECG indices of repolarization were significantly prolonged in tobacco smokers after smoking, whereas one of three indices was prolonged in e-cigarette smokers after vaping. What do these findings indicate about the sudden cardiac death risk of e-cigarettes compared to tobacco cigarettes? Does the e-cigarette rate of nicotine delivery have an impact on physiological effects? Listen now to learn how to present an evidence-based argument the next time a friend (or your child) tells you e-cigarettes are “safer” than smoking.


Michelle Ip, Evangelos Diamantakos, Kacey Haptonstall, Yasmine Choroomi, Roya S. Moheimani, Kevin Huan Nguyen, Elizabeth Tran, Jeffrey Gornbein, Holly R. Middlekauff Tobacco and electronic cigarettes adversely impact ECG indexes of ventricular repolarization: implication for sudden death risk  Am J Physiol Heart Circ Physiol, published April 21, 2020. DOI:

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