DYNAMIC COMPLIANCE OF THE LEG ARTERIAL VASCULATURE IN HEALTHY HUMANS

Abstract

Background It is unclear whether healthy aging results in reduced compliance of peripheral arteries in humans because a) past studies evaluating age differences in arterial stiffening used indirect measures (Pulse Pressure Tracing, Pulse Wave Velocity) b) studies examining the effects of aging on dynamic compliance in lower extremity arteries are lacking. Purpose To develop a technique for studying possible age-related alterations in dynamic peripheral artery compliance. Methods Simultaneous measurement of popliteal diameter (2D ultrasound) and dorsal pedal arterial pressure (tonometry) under resting conditions in younger (20–39) and older (60–79) men and women. Compliance (ΔArea/ΔPressure) was calculated using the pressure and area measured at end systole and end diastole. A pseudo-linear model was then employed for calculating dynamic compliance (DC) over a 4 mmHg window using a processing scheme that temporally registers tonometer and diameter signals with different sampling rates and corrects for phase shift due to different measurement sites. Results Preliminary mean values for DC during systole and diastole in females were calculated using the two-point and pseudo-linear model. No age related changes were seen using these calculations. Summary Subsequent studies will examine DC as the instantaneous derivatives at discrete pressures. Research supported by NIH award R01-AG-018246 (DNP)