The Relationships between the Repolarisation and Depolarisation Markers of Sudden Cardiac Death in Smokers

Backgroung: The risk of sudden cardiac death (SCD) and atrial fibrillation (AF) increase in smokers. This study aimed to determine the relationships between the repolarization and depolarization predictors of SCD in routine electrocardiography (ECG) in smokers. Methods: Between January and August-2019, ninety-eight healthy patients smoking for more than five years were included in the study group by simple random sampling. The control group consisted of one hundred twenty-two non-smokers. In the study and control group, following a routine physical examination and blood tests, P wave dispersion in the right precordial leads (PWdR) and the left precordial leads (PWdL), T peak-end interval in the right precordial leads (Tp-eR) and the left precordial leads (Tp-eL), QRS dispersion in the right precordial leads (dQRSR) and the left precordial leads (dQRSL), and QRS duration values in the right precordial leads (QRSR) and the left precordial leads (QRSL) were calculated in routine 12-lead ECG + right precordial leads. Results: There was a statistically significant moderate positive correlation between dQRSRxTp-eR/QRSR-value and smoking time in the study group. Also, there was a statistically significant weak negative correlation between dQRSLxTp-eL/QRSL-value and smoking time in the study group (Respectively, R=0.52, and P<0.01, R=0.41 and P<0.01). There was a significant difference between correlation ratio of dQRSRxTp-eR/QRS-value and smoking time and dQRSLxTp-eL/QRSL-value and smoking time in the study group (Z=5.73, p<0.01). Conclusions: In the current smokers, dQRSRxTp-eR/QRSR and dQRSLxTp-eL/QRSL values significantly higher than in the control group.