AJP - Heart and Circulatory Physiology, Vol 243, Issue 2 236-H242, Copyright © 1982 by American Physiological Society
Synergistic effects of pressure, distal resistance, and vasoconstriction on stenosis
W. P. Santamore, R. L. Kent, R. A. Carey and A. A. Bove
The synergistic effects of perfusion pressure, distal resistance, and
arterial vasoconstriction on stenotic hemodynamics were examined using an
in vitro arterial preparation. Canine carotid and coronary arteries were
attached to a perfusion apparatus. Perfusion pressure and distal resistance
were controlled independently. Arterial vasoconstriction was induced by
perfusing the artery with a 100 mM K solution. A stenosis was created by
partially inflating a balloon catheter within the artery. Pressure proximal
and distal to the arterial segment and flow were measured. For the coronary
arteries the combination of high perfusion pressure, high distal
resistance, and arterial vasodilation decreased stenotic resistance to 0.79
+/- 0.10 mmHg . ml-1 . min, whereas low perfusion pressure, low distal
resistance, and arterial vasoconstriction increased stenotic resistance to
22.40 +/- 4.90 mmHg . ml-1 . min (P less than 0.01). These large changes in
stenotic resistance were accompanied by maximum and minimum flow rates of
86.1 +/- 6.0 and 5.5 +/- 1.1 ml/min, respectively (P less than 0.01).
Qualitatively similar results were obtained with the carotid arteries. Thus
perfusion pressure, distal resistance, and arterial vasoconstriction acted
synergistically to greatly influence the severity of the stenosis.
