Acute effects of tobacco chewing on the systemic, pulmonary and coronary circulation

Tobacco use is highly prevalent in India, with almost half of adult men consuming tobacco in either smoke or smokeless forms (particularly chewing). Although cigarette smoking is known to produce acute hemodynamic effects, there is a lack of data concerning such effects of chewing tobacco.

The aim of this study was to determine the acute hemodynamic and coronary vasomotor effects of chewing tobacco.

Twelve habitual tobacco chewers (mean ± SD age 51.3 ± 6.9 years) undergoing elective coronary angiography were included in the study. Following coronary angiography, a 7F thermodilution Swan Ganz continuous cardiac output pulmonary artery catheter was used to continuously measure the right heart pressures and cardiac output. Having obtained baseline hemodynamic data, 1g of tobacco was given to be chewed. Subsequently, hemodynamic data were obtained periodically over a period of 60 minutes. A repeat left coronary injection was performed, 10 minutes after giving the tobacco, in the right anterior oblique view to estimate the diameter of the left anterior descending (LAD) artery by quantitative coronary angiography.

Chewing tobacco led to a significant acute increase in heart rate (from 68.3 ± 12.4 beats/min to 80.6 ± 14.6 beats/min, peaking at 10 minutes) and cardiac output (from 3.8 ± 0.45 L/min to 4.7 ± 0.64 L/min, peaking at 15 minutes). There were no significant changes in the right atrial, pulmonary artery, or wedge pressures and hence no change in the pulmonary vascular resistance. More importantly, chewing tobacco was associated with coronary vasoconstriction (proximal LAD diameter change from 3.17 ± 0.43 mm to 2.79 ± 0.37 mm; p-value 0.02; mid LAD diameter change from 2.75 ± 0.36 mm to 2.40 ± 0.22 mm; p-value 0.03).

Chewing smokeless tobacco leads to coronary vasoconstriction and also produces significant hemodynamic alterations. These changes may have a bearing on excess vascular disease.