家兔急性心肌梗死后心室颤动模型制作

Objectives: The purposes of this study were to produce a cardiac arrest(CA) model of post-acute myocardial infarction(AMI) in rabbits, and to observe how the myocardial ischemia affect the threshold of ventricular fibrillation(VF). Methods: 36 healthy rabbits were randomized into the control group, non-infarction group and the infarction group, 12 animals included each group. VF was induced in the each group by the percutaneous alternating current(AC) stimulation. The duration of AC stimulation, the rate of sustained VF, restoration of spontaneous circulation(ROSC) and the survival of 1h, the tendency of heart rate and blood pressure were compared in the three groups. Results: After the left anterior descent(LAD) was ligated in the infarction group, ECG showed a typical dynamic process of the myocardial infarction. The time from the start of AC stimulation to the CA in the infarction group was 51.25±16.25s, significant shorter than the non-infarction group and the control group, but no significant difference of the duration of VF and the rate of ROSC. Rabbits showed lower MAP and higher CVP in non-infarction group and the infarction group during this study, levels of MAP and beats of heart rate were descending, levels of CVP were increased gradually after ROSC, while compared with control group, respectively. Conclusion: Ligating the left anterior descent (LAD) in rabbits via thoracotomy could produce a model with acute myocardial infarction(AMI). But the thoracotomy would produce a hypotensive state in rabbits. AMI would downgrade the threshold of VF, and didn't increase the incidence of persistent VF and didn't decrease the rate of ROSC during the course of inducing the rabbits to VF with the percutaneous alternating current stimulation. However, AMI would shorten obviously the survival time after ROSC in the rabbits, which suggested that the myocardial ischemia would deteriorate the cardiac dysfunction after resuscitation.