title: Altered regulation of the myocardial microcirculation in young smokers.
abstract: Smoking is known to affect microcirculatory function in a middle-aged population. However, the effects of smoking on myocardial perfusion in young smokers have not been studied. Myocardial perfusion was measured in 15 smokers (24 +/- 2 years) and 15 nonsmokers (24 +/- 3 years) using positron emission tomography. Myocardial perfusion was measured at rest, during cold stress and during dipyridamole. Resting myocardial blood flow was similar in the two groups. The well-described correlation between rate-pressure product and myocardial blood flow was present only in the nonsmokers (r(2) = 0.61, p < 0.001). Myocardial blood flow corrected for the rate-pressure product declined during cold by 20% in the smokers [1.11 +/- 0.28 vs. 0.92 +/- 0.20 ml x g(-1) x min(-1) (p = 0.012)], but remained unchanged in nonsmokers [1.11 +/- 0.25 vs. 1.09 +/- 0.30 ml x g(-1) x min(-1) (p = NS)]. Dipyridamole-induced hyperemia was similar in the two groups [2.23 +/- 0.78 vs. 2.42 +/- 0.65 ml x g(-1) x min(-1) (p = NS)]. In conclusion, smoking induces abnormalities in myocardial microcirculatory regulation in young otherwise healthy smokers. The coronary flow reserve, however, is not significantly altered.
authors.affiliation: Department of Cardiology B, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: M M
authors.initials: MM
authors.lastname: Madsen
authors.forename: M
authors.initials: M
authors.lastname: Bøttcher
authors.forename: T
authors.initials: T
authors.lastname: Toftegaard Nielsen
authors.forename: J
authors.initials: J
authors.lastname: Czernin
mesh_terms: D004730:Endothelium, Vascular / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008833:Microcirculation; D012907:Smoking / Q000503:physiopathology*; D013997:Time Factors