Περίληψη:
Background Smoking is a major risk factor for cardiovascular morbidity
and mortality. Because previous studies have shown that smoking affects
vasomotor response, we hypothesized that smoking may also acutely alter
aortic elastic properties.
Methods and Results We studied 40 male current and longterm smokers who
underwent diagnostic cardiac catheterization for chest-pain evaluation.
Twenty subjects (age, 48+/-2 years, mean+/-SEM) were randomly assigned
to smoking and 20 (age, 47+/-2 years) to sham smoking studies. Aortic
elastic properties were studied with the determination of the aortic
pressure-diameter relation before smoking, every minute for the first 5
minutes after the initiation of smoking or sham smoking, and every 5
minutes for the following 15 minutes. Instantaneous diameter of the
thoracic aorta was measured with a special ultrasonic dimension catheter
developed in our laboratory and previously validated. Instantaneous
aortic pressure was measured at the same site as was diameter with a
Millar micromanometer. Smoking was associated with significant changes
in the aortic pressure-diameter relation that denote deterioration of
the elastic properties and were maintained during the whole study
period: the slope of the pressure-diameter loop became steeper
(baseline, 35.43+/-1.38; minute 1, 45.26+/-1.65; peak at minute 10,
46.36+/-1.69 mm Hg/mm; P<.001) and aortic distensibility decreased
(baseline, 2.08+/-0.12; minute 1, 1.60+/-0.08; nadir at minute 5,
1.54+/-0.07 x 10(-6) cm(2) . dyne(-1); P<.001). In contrast, no changes
in aortic elasticity indexes were observed with sham smoking.
Conclusions Smoking is associated with an acute deterioration of aortic
elastic properties. This effect of smoking may contribute to the
unfavorable consequences of smoking on the cardiovascular system.
Συγγραφείς:
Stefanadis, C
Tsiamis, E
Vlachopoulos, C
Stratos, C and
Toutouzas, K
Pitsavos, C
Marakas, S
Boudoulas, H and
Toutouzas, P
