title: The Effects of Cigarette Smoking on the Tp-e Interval, Tp-e/QT Ratio and Tp-e/QTc Ratio.
abstract: BACKGROUND
  Cigarette smoking increases the risk of sudden cardiac death. Smoking may predispose individuals to ventricular fibrillation and sudden cardiac death by altering ventricular repolarization and stimulating sympathetic nervous system activity.
  
  
  OBJECTIVE
  The aim of the study was to investigate the instantaneous effects of smoking on ventricular repolarization.
  
  
  METHODS
  The study included 47 healthy subjects; 24 long-term heavy smokers (10 women, mean age: 40 ± 5 years) constituted the study group, and 23 non-smokers (10 women, mean age: 42 ± 10 years) constituted the control group. ECGs were performed on all the subjects. The Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio were measured and compared between the groups.
  
  
  RESULTS
  There were no significant differences between smokers and nonsmokers in the basic clinical and echocardiographic variables (p > 0.05). The QT interval and QTc interval were similar in both groups. The Tp-e interval (p = 0.02) and Tpe/QT ratio (p = 0.001) were higher in the heavy smokers than in the non-smokers. The Tpe/QTc ratio (p = 0.001) was also higher in the smokers. Other ECG parameters were similar between the smokers and nonsmokers.
  
  
  CONCLUSIONS
  The results show that chronic cigarette smoking is associated with a prolonged Tp-e interval, increased Tp-e/QT ratio and Tp-e/QTc ratio. These observations may indicate that there may be a relationship between smoking and altered ventricular repolarization. Abnormal ventricular repolarization values on an ECG may explain the increased cardiovascular event risk in long-term heavy cigarette smokers.
authors.affiliation: Department of Cardiology, Özel Selçuklu Hospital, Konya, Turkey.
authors.forename: Tevfik F
authors.initials: TF
authors.lastname: İlgenli
authors.affiliation: Department of Cardiology, Golcuk Military Hospital, Kocaeli, Turkey.
authors.forename: Alptuğ
authors.initials: A
authors.lastname: Tokatlı
authors.affiliation: Department of Cardiology, Near East University, Nicosia, Cyprus.
authors.forename: Onur
authors.initials: O
authors.lastname: Akpınar
authors.affiliation: Department of Cardiology, Medipol University Hospital, Istanbul, Turkey.
authors.forename: Fethi
authors.initials: F
authors.lastname: Kılıçaslan
mesh_terms: D000200:Action Potentials; D000328:Adult; D016022:Case-Control Studies; D016757:Death, Sudden, Cardiac / Q000209:etiology; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology