Effects of Active Smoking on Heart Rate Variability, Heart Rate & Various Other Cardiac Risk Events in Chronic Smokers

Background: Smoking increases the risk of vasospasm and arrhythmias, and may decrease heart rate variability (HRV). Shown to increase the risk for cardiovascular diseases and autonomic dysfunction specifically, reduced heart rate variability (HRV)) is a predictor of increased cardiac risk however, no study has till now has evaluated the time onset of these electrophysiological changes following smoking.

Method: Male smokers with atypical chest pain were screened with TMT. A total of 31 patients in whom TMT was either negative or mildly positive, underwent a 24-hour holter monitoring and were asked to note down the time of smoking.

Results: Heart rate increased significantly during smoking and came back to normal after 30 minutes. Smoking is also associated with an increased risk of ectopics (mean of 5.28 prior to smoking to 9.81 per hour during smoking to 11.29 during the next hour after smoking p 0.001). 3 patients had significant ST-T changes after smoking that lasted for half to two hours. HRV index is significantly decreased in smokers but spectral parameters- SDNN, RMSSD and SDANN remained normal.

Conclusion: Smoking increases heart rate and ectopic significantly. Ischemic ST-T changes were also detected during smoking. Spectral parameters of HRV analysis of smoker remained with normal limits but more important geometrical parameter -HRV index showed significant abnormality.