The Journal of Thoracic and Cardiovascular Surgery, Vol 79, 904-910, Copyright © 1980 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Effect of graded narrowing of left main coronary artery on left ventricular function
RL Feldman, DA Conetta, WW Nichols, CJ Pepine and CR Conti
The relationship between left ventricular function and coronary blood flow
was studied in 16 chloralose-anesthetized dogs with an intact coronary
circulation and left ventricle. Left ventricular dimensions, hemodynamic
function indices, and coronary blood flow were measured simultaneously as
the origin of the left coronary artery was narrowed by a calibrated snare.
With a left coronary blood flow reduction of 17% (average), left
ventricular minor axis diameter increased and maximum aortic blood flow
acceleration and maximum rate of rise of left ventricular pressure
decreased. Other measured indices of ventricular function did not change
significantly. Larger coronary flow decrements caused a decrease in aortic
systolic and diastolic pressures, stroke volume and cardiac output and an
increase in heart rate and left ventricular end-diastolic pressure. These
results confirm a close relationship between left ventricular function and
blood supply.