Reperfusion of infarcting myocardium: benefit of surgical reperfusion in a chronic model.
Surgical reperfusion of experimental infarction leads to improved recovery of regional function compared with medical reperfusion, but sustained myocardial salvage has not been demonstrated. Twenty-two dogs were subjected to two hours of anterior descending occlusion and divided into three groups: group P (n = 7), no reperfusion; group M (n = 8), medical reperfusion; and group S (n = 7), controlled surgical reperfusion. Ischemia caused systolic bulging (-36% of control systolic shortening, p less than 0.01) and decreased regional work (9% of control pressure-length loop area, p less than 0.05). Thirty minutes after reperfusion group M had persistent systolic bulging (-9% of control systolic shortening) and decreased regional work (9% of control pressure-length loop area), whereas group S had +17% of control systolic shortening and 33% of control pressure-length loop area. After 1 week, regional function improved in all three groups (percent of control systolic shortening: group P, 26%; group M, 19%; group S, 52%), but systolic shortening was significantly better in group S (p less than 0.05 versus group M). Surgical reperfusion also resulted in one half of the eventual myocardial necrosis found in the other groups (group P, 45% of area at risk; group M, 38%; group S, 19%; p less than 0.05, group S versus group P or M). In this model, medical reperfusion offered no demonstrable benefit, whereas controlled surgical reperfusion led to a sustained (1 week) improvement in regional function and significant myocardial salvage.
Cheung
E H
EH
Department of Surgery, Carlyle Fraser Heart Center, Crawford Long Hospital, Emory University School of Medicine, Atlanta, Georgia.
Arcidi
J M
JM
Dorsey
L M
LM
Vinten-Johansen
J
J
Hatcher
C R
CR
Guyton
R A
RA
D000818:Animals; D003326:Coronary Circulation; D004285:Dogs; D006321:Heart / Q000503:physiopathology; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D015425:Myocardial Reperfusion / Q000009:adverse effects; D014693:Ventricular Fibrillation / Q000209:etiology