Early ischemia after complete coronary ligation in the rabbit, dog, pig, and monkey

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Abstract
The character and extent of the myocardial ischemic borderzone was assessed in the rabbit, dog, pig and monkey. A fluorophotographic technique permitting high resolution (.+-. 50 .mu.m) display of myocardial ischemia was developed. Reduced intracellular NADH ischemia) fluoresces and may be photographed while oxidized NAD (perfused tissue) does not. A coronary artery was ligated for 5 min in open-chest rabbits, dogs, pigs and monkeys. A fluorescent dye was injected into the left atrium as a coronary vascular marker and the tissue was quick-frozen. The ischemic margin was well seen and was jagged in all species. The distance from anoxic to perfused tissue (borderzone) was < 50 .mu.m in all species. A narrow O2-diffusion zone of nonperfused nonanoxic tissue is visible in isolated heart perfused with blood-free solution. The width of this zone is inversely related to myocardial O2 consumption and is < 50 .mu.m in a working blood-perfused heart. The O2 diffusion zone was correlated with the clinically defined salvageable borderzone. In dogs, collateral vessels provide a heterogeneous border to the ischemic region so that the canine ischemic pattern differs from that of pigs, rabbits and monkeys.