Changes in histopathology and tumor necrosis factor-α levels in the hearts of rats following asphyxial cardiac arrest

OBJECTIVE: Post cardiac arrest (CA) syndrome is associated with a low survival rate in patients who initially have return of spontaneous circulation (ROSC) after CA. The aim of this study was to examine the histopathology and inflammatory response in the heart during the post CA syndrome. METHODS: We induced asphyxial CA in male Sprague-Dawley rats and determined the survival rate of these rats during the post resuscitation phase. RESULTS: Survival of the rats decreased after CA: 66.7% at 6 hours, 36.7% at 1 day, and 6.7% at 2 days after ROSC following CA. The rats were sacrificed at 6 hours, 12 hours, 1 day, and 2 days after ROSC, and their heart tissues were examined. Histopathological scores increased at 12 hours post CA and afterwards, histopathological changes were not significant. In addition, levels of tumor necrosis factor-α immunoreactivity gradually increased after CA. CONCLUSION: The survival rate of rats 2 days post CA was very low, even though histopathological and inflammatory changes in the heart were not pronounced in the early stage following CA.