A comparison of techniques for measuring pulse wave velocity in the rat. Mitchell, Gary F., Marc A. Pfeffer, Peter V. Finn, and Janice M. Pfeffer. Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115
APStracts 3:0413A, 1996.
We evaluated methods for measuring average and regional pulse wave velocity along the full length of the aorta in 18 month old ether -anesthetized male spontaneously hypertensive rats. Catheter-tip manometers were placed in the ascending and descending thoracic aorta via the right carotid and left femoral arteries, respectively. As the distal catheter was withdrawn at 1 cm intervals, the relationship between distal catheter insertion distance and distance between transducers was determined from the intercept of the insertion distance vs. transmission delay regression line. Methods that assessed the foot-to-foot time delay between pressures accurately predicted the separation between catheters (measured distance, 14.3 cm; intercept, 14.0 0.5 cm; P = NS), were highly reproducible (coefficient of variation of 2.3% for repeated measurements), and showed minimal variability (range, 509 30 to 600 29 cm/s) along the full length of the aorta. Methods that made use of the pressure -pressure transfer function were spatially (range of values along the aorta 367 17 to 722 39 cm/s) and temporally more variable, especially during vasoconstriction with methoxamine, due to the effects of reflected waves. 

Received 12 June 1996; accepted in final form 20 August 1996.
APS Manuscript Number A551-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996