Abstract

Death resulting from acute neurogenic cardiovascular failure have been divided into primary shock caused by parasymphathetic stimulation and ventricular fibrillation caused by symphatheticoadrenal stimulation. Morphological characteristics have not been established in gross and microscopical finding in either cases. Hence this experiment was designed to provide some positive findings in differentiating these two cause of death. Primary shock or ventricular fibrillation was induced by electrical stimulation of the vagus nerve (5 volt, 50 Hz, 1.0 msec.) and of the chest wall (120 volt, 50 Hz, A.C.) respectively and rat myocardium were observed with electron microscope. 1) The heart of the rat which died from primary shock revealed relatively normal pattern of ultrastructural architectures in the myofilaments, myofibrils, sarcomeres, Z lines, mitochondria and other sarcoplasmic organelles. 2) The heart of the rat which died from ventricular fibrillation revealed shortening and scalloping of the sarcomeres, fragmentation of the Z lines, distortion of the myofilaments around the intercalted disc and displacement of the mitochondria away from the intercalated disc, appear to be similar to those of zonal lesion seen in the hemorrhagic shock. Furthermore, marked changes were noted in mitochondria. These changes consisted of swelling, destruction of the cristae, and abnormal cystic space formation with or without amorphous materials stic depression of glycogen particles were present. From these results, it might be suggested that the ultrastructural findings of the heart could provide the morphological differences between death from primary shock and ventricular fibrillation.