THE NATURE OF FLOW RESTRICTION DURING EXERCISE HYPEREMIA IN PERIPHERAL VASCULAR DISEASE

Abstract

1672 The purpose of our study was to examine the time course of exercise hyperemia in peripheral vascular disease (PVD). PVD is associated with arterial restriction and reduced vascular function. We predicted that PVD would be associated with a reduced and prolonged hyperemic response. We measured post-exercise blood flow in the popliteal arteries of 5 young (23-33 yrs), 4 older healthy persons (67-74 yrs), and 3 older subjects with mild-moderate PVD (71-77 yrs). The exercise consisted of 1 min toe raises. Prior to end of exercise a blood pressure cuff was inflated on the thigh to suprasystolic pressures. The cuff was released when the subject was in a supine position. Blood velocity in the popliteal artery was determined using duplex Doppler imaging. Reduced maximal velocity was observed in the old subjects with PVD. Young and healthy old subjects reached peak velocity immediately after cuff release with similar times to half return to resting velocity (young=44s, older=49s). PVD subjects reached peak velocities 48s after cuff release and had time to half return values of 132s. In PVD subjects flow increased an average of 44% between cuff release and peak velocity measurements. In summary, we found a reduced and prolonged hyperemic response in subjects with PVD. In addition, the time of peak velocity was delayed in PVD subjects compared to healthy subjects, which might be a result of the impaired vasodialating ability. Supported by NIH RR02305. The German Scholarship Foundation, and AUHS Institute on Aging