实验性急性心肌缺血的早期形态学指标探讨

A Study on the Morphological Criteria of Experimental Acute Myocardial Ischemia in Dogs and Rabbits

对犬和兔的冠状动脉分别形成不同程度的机械性狭窄和药物性痉挛1小时,观察冠状动脉狭窄后急性心肌缺血的早期形态学改变,探讨其形态学诊断标准。结果表明:光镜下急性早期缺血性改变为心肌细胞嗜伊红增强和较具特征性的心肌纤维波浪状变和收缩带形成。轻度波浪状变电镜下仅见轻度线粒体肿胀;重度波浪状变线粒体肿胀明显,嵴断裂、溶解消失、空泡变,肌原纤维肿胀、变性或断裂。波浪状变和收缩带并存时,Z线增宽,肌节呈节段性疑聚,形成典型之“竹根样”或“竹节样”改变。作者认为,轻度心肌纤维波浪状变不足以说明为心肌缺血性改变;重度波浪状变可作为早期心肌缺血的形态学指标;若波浪状变同时伴有收缩带形成时,表明心肌缺血程度严重。

The coronary arteries were mechanically stenosed in different degrees for 1 hour in 18 dogs, and coronary spasm were induced by drug in 24 rabbits. The morphologic changes of early acute myocardial ischemia were studied with both light and electron microscope. The wavy phenomenon of myocardial cells was found in all animals of the experimental groups, and were classified into mild, medium and severe (I, II and III) grades. Grades II-III were found often associated with contraction bands of rnyocardial cells. There was no evident characteristic lesion observed under electromicroscope in grade I,but in grades II-III, there were edema and muscular rupture of myocardial cells, swelling and fragmention or vacuolation of mitochondria, and myocomma coagulum during formation of contraction bands. The results suggested that wavy phenomenon in grades II-III may be a morphlological sign of early acute myocardial ischemia, while an association with contraction band would indicate a more severe ischemia.