AJP - Heart and Circulatory Physiology, Vol 246, Issue 6 768-H775, Copyright © 1984 by American Physiological Society
Coronary, collateral, and perfusion territory responses to aortic banding
K. W. Scheel, B. L. Eisenstein and L. A. Ingram
The objectives of this study were 1) to separate anatomic from functional
variables causing the increased minimal coronary resistance seen with
hypertrophy; 2) to investigate whether increased intraluminal pressure and
tangential wall stress lead to collateral proliferation; 3) to define
changes in vascular perfusion territories resulting from hypertrophy.
Coronary and collateral resistances of the four coronary arteries were
determined in empty, beating hearts from 10 control dogs and 11 dogs with
myocardial hypertrophy produced by 4 wk of aortic banding. In hypertrophied
hearts the coronary flow per gram at 100 mmHg and the slope of the
pressure-flow line were significantly decreased. Coronary flow-to-body
weight ratios were not different; thus the decreased flow per gram tissue
with hypertrophy was due to increased tissue mass rather than changes in
vascular resistance. Collateral flows were similar for both groups,
indicating that increased pressure and wall stress did not cause
significant collateral growth. Both ventricles hypertrophied and all
vascular beds were equally affected, but distribution of the increased mass
varied for different vascular beds.
