抄録
Intracoronary thrombodynamics in the early phase of acute myocardial infarction were studied in an experimental canine model. Intracoronary thrombus was precipitated at the mock ruptured atheromatous plaque consisting of cholesterol and collagen. (1) Myocardial infarction occurred in 10 and sudden death in 2 secondary to intracoronary thrombotic occlusion in 15 control experiments. (2) Pretreatment with an antiplatelet drug, ticlopidine, significantly reduced the incidence of myocardial infarction and sudden death (7/18, 39% vs. 12/15, 80%, p < 0.05). (3) During the period when intracoronary thrombus was precipitated, a transient reduction in aortic pressure induced by nitroglycerin resulted in rapid progression of intracoronary thrombotic occlusion in 7 of 21 animals and in 5 of 17 animals treated with nitroprusside. The terminated coronary blood flow could be restored by raising coronary perfusion pressure with methoxamine in 5 of 10 cases with coronary thrombotic occlusion. (4) Cigarette smoking appeared to accelerate the completion of coronary thrombotic occlusion. (5) Sudden death occurred in 12 of 43 models without pharmacological intervention during coronary thrombotic occlusion associated with myocardial dysynergy. Six sudden deaths occurred within 10 min and 9 within 30 min following coronary thrombotic occlusion. Postmortem complete autolysis of intracoronary thrombus was observed in 24% and partial thrombolysis in 28%.
