Abnormal ventricular repolarization, as indicated by prolonged Tpeak-end (Tp-e), is associated with increased sudden death risk. Baseline ECG indexes of repolarization, Tp-e, Tp-e/QT, and Tp-e/QTc, were not different among tobacco cigarette (TC) smokers, electronic cigarette (EC) users, and nonsmokers at baseline, but when TC smokers smoked one TC, all parameters were prolonged. Using an electronic cigarette with nicotine, but not without nicotine, increased the Tp-e/QT. Smoking induces changes in ECG indexes of ventricular repolarization associated with increased sudden death risk.

doctoral students from the same class group as the student authors of this article, provided assistance on SAS programming, statistics, writing, and language editing at various stages of manuscript development. No compensation was provided for this assistance.