Comparison between two rat models of cardiac arrest: asphyxiation and ventricular fibrillation / 上海交通大学学报（医学版）

ABSTRACT

Objective·To compare the differences in cardiac function and neurological function between asphyxia and ventricular fibrillation (VF)induced cardiac arrest rat model.Methods·Twenty healthy adult male SD rats were randomly divided into VF group (n=8),asphyxial group (n=8)and sham group (n=4).Cardiac arrest models were established in VF group and asphyxial group by VF and asphyxia respectively.All animals were observed for 24 h and advanced life support was offered for the first 1 h after resuscitation.During the 24 h,ejection fraction (EF) and cardiac output (CO) were measured with the help of cardiac ultrasonography at 1,3,5 and 6 h post resuscitation.Electrocardiographic changes,24 h survival analysis and neurological deficit score (NDS) were also recorded and analyzed at 6,12,18 and 24 h post resuscitation.Results·Both EF and CO decreased dramatically after resuscitation compared with sham group at the same time point (P=0.000).At 1 h post resuscitation,the CO decreased from (98.84±4.86)mL/min to (59.17±22.99) mL/min in VF group and from (99.86±10.34) mL/min to (46,02±22.32) mL/min in asphyxial group,but there was no difference between the two groups (P=0.792).At 3,5 and 6 h post resuscitation,the CO in VF group was higher than that in asphyxial group (P=0.041,P=0.007,P=0.020).At 1 h post resuscitation,the EF decreased from (82.67±6.21)％ to (70.23±13.24)％ in VF group and from (83.24±3.01)％ to (65.46±13.11)％in asphyxial group,but no difference was observed between the two groups (P=0.877).Then a recovery tendency was observed in both groups,but more obvious in VF group at 3 and 5 h post resuscitation (P=0.031,P=0.024).No difference was found between the two groups in survival rate during 24 h and the NDS after resuscitation,although the neurological function was greatly impaired.Conclusion·VF and asphyxia are most commonly used methods to induce cardiac arrest,but these models may differ in cardiac function post resuscitation.Researchers need to choose appropriate models according to their study objectives.