ISSN:
1542-474X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Cigarette smoking is strongly related to decreased vagal cardiac activity and increased cardiac death. We sought to examine the short-term effects of smoking on heart rate variability (HRV) in healthy young subjects in the sitting position to investigate the influence of smoking on autonomic cardiac control.〈section xml:id="abs1-2"〉〈title type="main"〉MethodsThirty-two healthy volunteers (18 males, 14 females, 21 habitual smokers and 11 nonsmokers, mean age 30 ± 3 years, range 24–36 years) were studied. Smokers were asked not to smoke for 8 hours prior to examination. Mean, SDNN, rMSSD, pNN50, total power, LF, HF, and LF/HF ratio were measured for 30 minutes, divided into six periods of 5 minutes each. Smoking of a single cigarette took place during the second period.〈section xml:id="abs1-3"〉〈title type="main"〉ResultsSmoking caused a significant increase of the LF/HF ratio and of the normalized values of the LF component. A significant decrease in absolute values of total power, LF, and HF components was noticed. All time-domain indices were significantly decreased. We also noticed that although the changes appeared during smoking (second period) the maximal changes were documented 5 to 10 minutes after smoking cessation (third and fourth periods).〈section xml:id="abs1-4"〉〈title type="main"〉ConclusionsCigarette smoking in the sitting position causes a transient decrease in vagal cardiac control and a moderate sympathetic activation. These changes last for at least 30 minutes and are compatible with a modulation of the autonomic control of the sinoatrial node toward sympathetic predominance. Despite the differences concerning the baseline HRV measures between nonsmokers and habitual smokers, an almost identical pattern of sympathovagal modulation was observed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1542-474X.1999.tb00061.x
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