The effect of smoking on the cardiovascular autonomic functions tests

Abstract

Tobacco smoking is one of the major causes of preventable morbidity and mortality all over world. Smoking affects the cardiovascular system by several mechanisms. The present study was planned to study the effect of smoking on the cardiovascular autonomic functions among smokers.This study comprises 50 male subjects aged between 20 to 30 years, who included 25 smokers who formed cases and 25 non-smokers who formed the control groups were selected for this study. The design for this study is cross-sectional survey. The subjects were from patients who attended medicine OPD. Inclusion and exclusion criteria are followed in selecting participants. 1: Prior informed written consents were obtained from them after explaining to them, the procedure and the purpose of the study tests; 2. Ethical approval was taken from ethical committee of BMCH, Chitradurga.The cardiovascular autonomic function tests were assessed by using a CANWIN AUTONOMIC ANALYSER which was available in the department.In our study, it was observed that there was significant difference between the mean values of the para-sympathetic function tests among the smokers and the non-smokers (i.e. p<0.01) The Resting Heart Rate had significantly increased and the Expiration: Inspiration Ratio, the 30:15 Ratio (Response to standing) and the Valsalva Ratio had significantly decreased in the smokers as compared to those in the non-smokers. In this study, it was observed that there was no significant difference between the mean values of the Postural hypotension test (i.e. p>0.05) and that there was a highly significant difference between the mean values of the Sustained handgrip test in the smokers and the non-smokers (i.e. p<0.01). The Resting Heart Rate had significantly increased in case of smokers as compared to non-smokers due to increased sympathetic activity due to release of catecholamines. The Expiration: Inspiration Ratio, 30:15 Ratio (Response to standing) and the Valsalva Ratio had significantly decreased in the smokers as compared to those in the non-smokers due to derangement in parasympathetic activity.In sustained handgrip test, rise in blood pressure is decreased in smokers as compared to non-smokers due to reduced sympathetic activity.