RESUMO
Fifteen healthy and non smoking men, age range 20 to 27 years (23.6 +/- 2.5 (SD) were subject of a double blind study designed to compare the immediate cardiovascular effects of smoking "regular" and "light" cigarettes (nicotine content: 1.1 mg and 0.6 mg, respectively). The measured cardiovascular parameters were: heart rate, blood pressure, echographic calculations of the left ventricle fractional shortening, amplitude of the posterior wall systolic movement and posterior wall contraction velocity, as well as QTc interval and T wave amplitude. All those measurements were obtained before and after smoking one or two other kind of cigarette. When the changes evoked by the regular cigarette were compared to the changes evoked by the light cigarette, no significant difference was detected. When analyzing the modifications that each kind of cigarette produced to its respective basal-control measurement the following observations were detected: heart rate increased after smoking both types of cigarette (p less than 0.001), blood pressure was raised only with regular cigarette (systolic, p less than 0.002; diastolic, p less than 0.005). QTc interval was prolonged (p less than 0.05) and T wave amplitude decreased (p less than 0.02) after regular and light cigarette. It is concluded that tobacco of regular and light cigarettes significantly and immediately affects diverse cardiovascular parameters, but there is no a clear or definite difference when the changes produced by the two types of cigarette are compared to each other, at least at the level of nicotine here utilized.