Nicotine exacerbates postischemic contractile dysfunction of 'stunned' myocardium in the canine model. Possible role of free radicals.

There is no doubt that high doses of nicotine have deleterious effects on cardiovascular function. However, the effects of lower and more clinically relevant doses of nicotine have received little attention, and the consequences of nicotine in the setting of ischemia/reperfusion are virtually unknown. The first objective of this study was to determine whether nicotine, given either before or after ischemia and at a dose mimicking that absorbed by humans during inhalation of one cigarette, exacerbated contractile dysfunction of canine myocardium "stunned" by brief transient ischemia. The second aim was to provide preliminary insight into the mechanism of action of nicotine on the stunned myocardium.