The Journal of Thoracic and Cardiovascular Surgery, Vol 95, 631-636, Copyright © 1988 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
The effect of oxygen free radical scavengers on the recovery of regional myocardial function after acute coronary occlusion and surgical reperfusion
F Gharagozloo, FJ Melendez, RA Hein, RE Austin, RJ Shemin, VJ DiSesa and LH Cohn
Department of Surgery, Harvard Medical School, Boston, Mass.
This study investigated the effects of the oxygen free radical scavengers
superoxide dismutase and catalase, the peroxide ion inhibitor, in
crystalloid potassium cardioplegic solution on infarct size and global and
regional myocardial function after occlusion of the left anterior
descending artery and surgical reperfusion in young sheep on
cardiopulmonary bypass. After 1 hour of occlusion, the animals were
randomized to receive either routine potassium cardioplegia or cardioplegia
with superoxide dismutase and catalase. Global hemodynamics measured by
maximum rate of pressure rise showed significant improvement after 5 hours
of reperfusion in the group treated with superoxide dismutase and catalase
(1843 +/- 163 versus 979 +/- 191, p less than 0.001). Regional myocardial
function was measured by ultrasonic crystals implanted in the ischemic area
and in a nonischemic control segment. The percent systolic shortening or
bulging was calculated. At end of reperfusion in the animals treated with
superoxide dismutase and catalase, there was active shortening in the
ischemic area after reperfusion of +9.2% +/- 0.4% versus 2.1% +/- 0.8% in
untreated animals (p less than 0.001). Infarct size measured by
triphenyltetrazolium chloride staining showed significant difference (p
less than 0.001) between animals treated with superoxide dismutase and
catalase (0.9% +/- 0.1%) and control animals (61% +/- 70%). Superoxide
dismutase and catalase given in the cardioplegic solution before
reperfusion of an acutely ischemic area of myocardium enhances recovery of
contractile function and results in a significant reduction in infarct
size, which suggests improved salvage of the ischemic myocardium.
