Vascular Reactivity: Evaluation of an acute suprasystolic occlusion with impedance plethysmography

— In the clinical set, the evaluation of endotheliumdependent vasodilator response of large vessels is carried out using ultrasound equipment for vascular flow determinations and during administration of vasoactive drugs. This work proposes to use a substantially cheaper technique and a sustained cuff arterial occlusion in order to cause vasodilation. Impedance plethysmography is used to detect the arterial pulse wave over radial artery while the forearm is occluded by above the recording site. From these plethysmographic waves, three indexes and their changes -between control and maximal response post-occlusionwere calculated. 33 complete records obtained from healthy low-risk volunteers were analyzed. Between control and post-occlusion maximal response, “average percentual change of pulse wave amplitude” were (35±13)%, “stiffness index” did not show significant differences (6,38±0,98 vs 6,38±0,94 and “reflection index” was significant lower (58±15 vs 35±16)%. These results indicate that: 1cuff occlusion maneuver was effective to cause endothelium-dependent vasodilation, 2changes of pulse wave amplitude and reflection index could be used as markers of atheroarteriosclerotic damage in the vascular bed, even in sub-clinical conditions.