Document Type : Original Article(s)

Authors

• Mohammad Ali Akbarzadeh ¹
• Shahrooz Yazdani ²
• Mohamad Esmail Ghaidari ³
• Mohammad Asadpour-Piranfar ³
• Negar Bahrololoumi-Bafruee ⁴
• Allahyar Golabchi ⁵
• Amirhossein Azhari ⁶

¹ Assistant Professor, Department of Cardiology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

² Cardiologist, Department of Cardiology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

³ Associate Professor, Department of Cardiology, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran

⁴ General Practitioner, Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical & Research Center, Iran University of Medical Sciences, Tehran, Iran

⁵ Cardiologist, Fellowship of Interventional Electrophysiology, Shaheed Beheshti Hospital, Kashan University of Medical Sciences, Kashan, Iran

⁶ Fellowship of Pacemaker and Invasive Electrophysiology, Department of Electrophysiology AND Shaheed Rajaei Cardiovascular & Medical Research Center, Iran University of Medical Sciences, Tehran, Iran

Abstract

BACKGROUND: Cigarette smoking increases the risk of ventricular fibrillation and sudden cardiac death (SCD). QT dispersion (QTD) is an important predictor of cardiac arrhythmia. The aim of this study was to assess the acute effect of smoking a single standard cigarette containing 1.7 mg nicotine on QT interval and QTD in healthy smokers and nonsmokers. METHODS: The study sample population consisted of 40 healthy male hospital staff, including 20 smokers and 20 nonsmokers. They were asked to refrain from smoking at least 6 h before attending the study. A 12-lead surface electrocardiogram (ECG), recorded at paper speed of 50 mm/s, was obtained from all participants before and 10 min after smoking of a single complete cigarette. QT interval, corrected QT interval, QTD, and corrected QT dispersion (QTcD) were measured before and after smoking. RESULTS: Smokers and nonsmokers did not have any significant differences in heart rate (HR) (before smoking = 67.35 ± 5.14 vs. 67.70 ± 5.07, after smoking = 76.70 ± 6.50 vs. 76.85 ± 6.50, respectively), QTD (before smoking = 37.75 ± 7.16 vs. 39.15 ± 6.55, after smoking = 44.75 ± 11.97 vs. 45.50 ± 9.58, respectively), and QTcD (before smoking = 39.85 ± 7.40 vs. 41.55 ± 6.57, after smoking = 50.70 ± 14.31 vs. 51.50 ± 11.71, respectively). However, after smoking a single cigarette, HR, mean QTD, and QTcD significantly increased (all had P value <0.001) in comparison to the measures before smoking. CONCLUSION: Smoking of a single complete cigarette in both smokers and nonsmokers results in significant QTD increase, which can cause arrhythmia and SCD.   Keywords: Cardiac, Death, Electrocardiography, Smoking, Sudden