Arterial blood nicotine concentration and coronary vasoconstrictive effect of low-nicotine cigarette smoking.

Low-nicotine cigarettes have been advertised to the public as less harmful to the cardiovascular system. We studied the effects of smoking two low-nicotine cigarettes on arterial and venous blood nicotine levels, hemodynamics, and coronary vascular tone in 12 patients referred for diagnostic coronary arteriography. All were chronic smokers as evidenced by their elevated baseline arterial and venous cotinine blood levels (139 +/- 30 ng/ml and 155 +/- 34 ng/ml, respectively). High-resolution coronary angiograms were evaluated "blindly" before and after smoking. An electronic caliper was used to measure the diameter of disease-free coronary segments of the left anterior descending and circumflex arteries. Arterial nicotine levels rose from 5 +/- 1 ng/ml at baseline to 37 +/- 7 ng/ml (p less than 0.01) after the first cigarette was smoked and to 45 +/- 8 ng/ml (p less than 0.01) after the second cigarette. Venous nicotine levels rose from 8 +/- 2 ng at baseline to 15 +/- 3 ng/ml (p less than 0.05) after the first cigarette and to 20 +/- 3 ng/ml (p less than 0.01) after the second cigarette. After the first cigarette heart rate increased 8 +/- 2 beats/min (p less than 0.003) and double product 1229 +/- 400 beats/min x mm Hg (p less than 0.02). Compared to baseline values, after the second cigarette heart rate increased 9 +/- 1 beats/min (p less than 0.001) and double product 1767 +/- 486 beats/min x mm Hg (p less than 0.01). Systolic, diastolic, and mean blood pressure did not change significantly after either the first or second cigarette.(ABSTRACT TRUNCATED AT 250 WORDS)