[Rheographic evaluation of peripheral blood flow during isometric exercise]

A rheographic evaluation of peripheral blood flow during isometric contraction (handgrip) has been done in 25 attendants of the Air Force Medical Service (mean age :20 years). The velocity of sphygmic wave, the sphygmic amplitude and, the peak time, heart rate and blood pressure have been measured at rest and during handgrip. The velocity of sphygmic wave does not change in all the subjects; the sphygmic amplitude is decreased of 10% (p less than .001), the peak time is decreased of 9% (p less than .001). Because sphygmic amplitude and peak time are directly proportional to flow volume, and their reduction significantly express a decrease of flow volume. The authors believe that the blood flow reduction is induced by the excitation of sympathetic peripheral alpha-receptors, not more balanced from sympathetic cholinergic vasodilator fibers. The actual result is an increase of the peripheral vascular resistances.