AJP - Heart and Circulatory Physiology, Vol 235, Issue 4 429-H434, Copyright © 1978 by American Physiological Society
Effects of coronary ligation of the chromically sympathectomized dog ventricle
C. E. Jones, L. Y. Beck, E. DuPont and G. E. Barnes
The cardiac response to acute coronary occlusion was studied after chronic
ventricular sympathectomy. Infarct size was measured using nitro blue
tetrazolium. In 11 control dogs, 8 dogs with ventricles sympathectomized 2
wk earlier, and 5 sham-operated dogs, mean infarct size was 20.0%, 8.9%,
and 20.4% of the left ventricular weight, respectively. Infarct size in
sympathectomized ventricles was significantly less than in control or
sham-operated hearts (P less than 0.05). Left ventricular perfusion before
and after coronary occlusion was measured in 10 controls and 7
sympathectomized ventricles using tracer microspheres. Preocclusion flow
values in chronically sympathectomized ventricles were approximately 30-40%
less than in controls even though arterial pressure and heart rate were no
different, suggesting an increased efficiency. Furthermore, after
coromanary occlusion, collateral perfusions in the central and peripheral
ischemic zones of the sympathectomized ventricles were 200-400% of those in
nonsympathectomized ventricles. When collateral perfusion was related to
the respective preocclusion flows, the difference between control and
sympathectomized ventricles was even greater. Thus, chronic ventricular
sympathectomy results in reduced infarct size, and this effect may be due
to a reduced flow demand as well as to an increased collateral perfusion.
