Quantitative synthesis of head and foreleg arterial pulses in the dog

¹ Department of Physiology, Medical College of Georgia, Augusta, Georgia

The carotid and the subclavian arterial-systems were treated as though composed of a series of homogeneous distensible tubes joined in series or in parallel. With minor corrections, the contour of the aortic arch pulse was taken as that of a single transient incident wave entering the proximal end of these systems. Pulse height changes were localized to the junctions between coupled tubes of dissimilar wave impedance values. The amount of pressure change at these junctions was calculated by comparing arterial pulses recorded from various sites in these systems with the aortic pulse. An attempt was made to keep a strict accounting of all reflected waves arising either from the junction points or from peripheral drainage beds. The pulse constructions provided evidence for appreciable junctional positive reflections which alter the contour of the peripheral pulses. Because returning reflected waves from these sites were reflected negatively at each junction, their amplitude on entering the aorta was relatively small. The good-to-excellent reconstructions of the actual pulse contours suggest that the method of analysis used has promise, and that the basic assumptions on which the calculation of reflection coefficients was based did not impose errors of critical importance.

Key Words: wave impedance and reflection • arterial reflection coefficients • branched tube hydraulic model

Submitted on July 20, 1964