Characteristic features of the differential sphygmogram in peripheral vascular dilation

Characteristic features of differential sphygmogram were investigated in persons in whom the radial circulation had been interrupted in order to produce a partial distension of muscular-type arteries and minute peripheral vessels. Eighteen subjects aged 20-35 years were examined. The differential and volume sphygmograms were recorded in the radial artery. After a five-minute stoppage of the circulation, the following characteristic features of the differential sphygmogram were observed: 1) the differential curve assumed the shape of a triangle with a broad base; 2) the amplitudes of all wave components decreased, the B wave disappeared, the V2 wave was minimal, and the t2 time considerably extended. The ratios V2/V1 and V2/(V1 +V2) were considerably diminished. These ratios may serve as fundamental criteria for the appraisal of vascular elastic properties in an intact organism.