RESUMO
<p><b>OBJECTIVE</b>To observe the protective effects on acute myocardial infarction of QDYX in dog.</p><p><b>METHOD</b>The corconary ciculation and cardial oxygen metabolism, the degree and range of myocardial ischemia, myocardial infarct size, and the changes of the enzymes in serum were determined by using the acute myocardial infarction model of ligation of LAD in the anaesthetized open-chest dogs.</p><p><b>RESULT</b>The coronary resistance and cardial oxygen consumption were decreased and the myocardial blood flow was increased in dogs treated with QDYX of 1.0,2.0 mg.kg-1. The degree and range of myocardial ischemia, myocardial infarct size and the activity of serum CK, LDH were decreased in acute myocardial infarcion dogs treated with QDYX of 1.0,2.0 mg.kg-1.</p><p><b>CONCLUSION</b>QDYX can decrease cardial oxygen consumption in dogs, thus having protective effect on myocardial ischemia.</p>