Smoking and mechanisms of cardiovascular control.

In humans short-term administration of nicotine, whether by smoking or intravenous injection, will typically raise blood pressure by 5 to 10 mm Hg and heart rate by 10 to 25 bpm. Smoking causes reduced myocardial contractility and left ventricular function in patients with angina pectoris or heart failure. Nicotine's mechanism of action is more complex than the classic concept of nicotinic ganglionic stimulation can account for. Nicotine exerts a potent pressor effect in the ventral lateral medulla (C-1 area). Little current data are available documenting the efficacy of centrally acting antihypertensive agents and converting-enzyme inhibitors with regard to preventing nicotine's acute cardiovascular effects.