Comparison of myocardial injures between asphyxia and ventricular fibrillation models of cardiac arrests北大核心CSCD

Objective: To compare the difference in cardiac injuries between asphyxia and ventricular fibrillation modes in different periods after cardiac arrest (CA). Methods: The model was established in Cardiopulmonary Resuscitation Lab, Sun Yat-sen University. A total of 35 male SD rats were used to produce the asphyxia or ventricular fibrillation (VF) cardiac arrest models randomly. Both of the two modes were induced 8 minutes cardiac arrest. The myocardial HE stains, mitochondrial respiratory control ratio (RCR), and echocardiography were observed at 4 h, 24 h and 72 h after ROSC (restoration of spontaneous circulation). The results were expressed as (x¯±s), t test was performed to compare between two groups, and one way analysis of variance was used to compare multiple groups. P <0. 05 was considered as significant difference. Results: HE stains showed damages were more serious in the VF mode than in asphyxia mode at 4 h, and both of them had a disorderly-arranged myocardium at 72 h. RCR in VF mode became worse at 4 h, and RCR resumed at 24 h in both modes without significant difference compared with the sham operated rats. The echocardiography showed VF mode had a lower left ventricular ejection fraction (LVEF) than asphyxia mode at 4 h (29.68% vs. 42. 16%, P =0. 03), and there was no difference in LVEF between VF mode and the sham operated rats at 24 h, however no difference in LVEF between the asphyxia and sham operated rats at 72 h. Both of them had a thicker left ventricular anterior wall than the sham operated rats at 72 h (2. 41 mm vs. 1. 72 mm, P = 0. 013; 2. 61 mm vs. 1. 72 mm, P = 0. 007), and there was no significant difference between them. Conclusions: The ventricular fibrillation mode has a more severe injuries in early period, but it recovers sooner than asphyxia one. Both of two groups get compensatory left ventricular hypertrophy in later period of ROSC.