The Annals of Thoracic Surgery, Vol 44, 350-355, Copyright © 1987 by The Society of Thoracic Surgeons
Controlled reperfusion following regional ischemia
HL Lazar, J Wei, FM Dirbas, GB Haasler and HM Spotnitz
Department of Surgery, Columbia University, College of Physicians and Surgeons, New York, NY.
The ability to reverse acute coronary occlusion with fibrinolytic agents
and percutaneous transluminal angioplasty has increased interest in the
revascularization of ischemic myocardium. This study defines changes in
global ventricular function, mass, and compliance during acute coronary
occlusion and following reperfusion with blood in the beating and arrested
heart. In 17 dogs on cardiopulmonary bypass, the proximal left anterior
descending coronary artery was occluded for 45 minutes. In 12 dogs, flow
was reestablished by releasing the coronary snare in the beating heart. In
the other 5 dogs, the snare was released during a continuous 10-minute
infusion of blood potassium cardioplegia in the arrested heart. Coronary
occlusion resulted in significant decreases in stroke work index and left
ventricular (LV) mass, but compliance was unchanged. Reperfusion in the
beating heart increased LV mass compared with the values measured before
ischemia (104 +/- 5 versus 95 +/- 5 gm; p less than 0.05) and decreased LV
compliance (39 +/- 4 versus 53 +/- 4 ml at LV end-diastolic pressure of 8
mm Hg; p less than 0.05). In contrast, with blood cardioplegia-based
reperfusion in the arrested heart, LV mass and LV compliance remained
unchanged from control values. We conclude that revascularization of
acutely ischemic myocardium in the beating heart further impairs LV
function by increasing LV mass and decreasing compliance. This damage can
be avoided by reperfusion with blood cardioplegia in the arrested heart.
