Experimental study on sudden death due to acute myocardial infarction.

为探讨猝死与心肌梗死发生时间的关系，寻找一种适合于急性心肌梗死检测的染色方法，采用结扎杂种犬左冠状动脉前降支分支的方法，造成急性心肌缺血模型。在心动周期的易损期对心脏进行电刺激，估计心室颤动阈值。结扎冠状动脉后15-30 mm，室颤阈值下降至对照组的20%左右。然后，随着冠脉结扎后时间的推移，ii增加，并显示几乎相同的值与对照组心脏冠脉结扎后4小时。用10%福尔马林溶液固定缺血心脏。将来自缺血心肌的切片用Luxol固蓝（LFB）溶液染色24小时，并在75%乙醇的几次变化中分化1-3分钟以形成淡蓝色（新修改的LFB染色）。改良LFB染色显示冠脉结扎后15-30 min心肌缺血性改变。结果提示，室颤猝死最易发生在心肌梗塞后15-30分钟，新改良的LFB染色法可用于检测此类极早期心肌梗塞。

To Investigate the relatlonshIp between sudden death and the time elapsed after the onset of myocardial infarction and to find a suitable staining method for detection of acute myocardial Infarction, an experimental model of acute myocardial ischemia was made with mongrel dogs by ligating anterior descending branch of left coronary artery. The heart was given electrical simulation at the vulnerable period of the cardiac cycle and the ventricular fibrillation threshold was estimated. Ventricular fibrillation threshold decreased to about 20 % of those of the control hearts 15-30 mm after the coronary artery ligation. Then ii increased with the time elapsed after the coronary ligation and showed almost same values as those of control hearts 4 h after the coronary ligation. The ischemic hearts were fixed with 10 % formalin solution. The sections from the ischemic heart muscle were stained with Luxol Fast Blue (LFB) solution for 24 h and were differentiated for 1-3 min in several changes of 75 % alcohol to a faint dove-colored blue (a newly modified LFB staining). The newly modified LFB staining revealed the myocardial ischemic changes 15-30 min after the coronary ligation. The result suggested that sudden death from ventricular fibrillation is the aptest to occur 15-30 min after the onset of myocardial infarction and the newly modified LFB staining Is useful for detecting such very early myocardial infarction.