Development and evaluation of a new canine myocardial infarction model using a closed-chest injection of thrombogenic material

A new canine myocardial infarction model using thrombi induced by closed-ch est injection of thrombin and autogenous brood with fibrinogen into coronar y arteries was developed. Occlusive thrombi were formed in all treated anim als. Occluded vessels did not spontaneously reperfuse 1 day after occlusion , but did so within 3 days. Infarction was confirmed by increased levels of creatine kinase-MB, glutamate-oxaloacetate transaminase and alpha-hydroxyb utyrate dehydrogenase, Additionally, the left ventricular ejection fraction (LVEF) decreased within 0.5 h after occlusion and had not improved 4 weeks later, After 1 week, extensive transmural anteroinferior myocardial infarc tion was observed and heart mass had increased. By 4 weeks after occlusion, pulmonary capillary wedge pressure and central venous pressure were increa sed, and oxygen pressure was decreased. Dropout of nuclei in cardiomyocytes and increased amount of collagen fiber were observed in myocardial infarct regions of hearts excised 4 weeks after occlusion. This canine model may b e useful and convenient in evaluating treatment efficacy and the long-term outcome of acute myocardial infarction.