Evaluation of the Cardiovascular Risk by Early ECG Changes in Smokers – A Cross Sectional Study

Abstract

Background: Smoking is a major risk factor for coronary artery disease. Nicotine, an important component of cigarette smoke is known to cause electrophysiological changes on the ECG which if identified early can contribute to prevention of Coronary artery disease. Objective: To evaluate the association of ECG changes in smokers compared with non -smokers. Subjects and Methods: A cross sectional study was undertaken in a Government Medical College in Chennai comprising of 150 healthy male smokers (with no known pre-existing disease) divided into three groups based on pack years of smoking and a fourth group of 50 healthy male non-smokers that served as the control group. A resting 12 lead ECG was taken for all the study participants and the ECG parameters were analysed. Simple descriptive statistics, Chi-square test and student’s independent t-test were employed for statistical analysis of the data. Results: ECG abnormalities were found to be more prevalent in smokers (23.33%) than in non smokers (10%) The ECG changes observed were an increased heart rate, increased QTc interval, increased P wave amplitude and decreased S-T segment duration even in apparently young healthy smokers. A statistically significant association was also seen between the prevalence of ECG changes and pack years of 5 or more. Conclusion: Electrophysiological changes develop even in healthy smokers, increasing with higher pack years of smoking. The ECG is a simple, cost effective tool that can be used to motivate smoking cessation and early intervention to reduce cardiovascular morbidity and mortality.