Study On The Changes Of Q-T Interval Cx43 And Arrhythmia Induced By Acute Traumatic Stress In Rats

Objective: Through the research of heart gap junction protein Cx43 in acute traumatic stress rat,the change of QT interval and ventricular arrhythmia(VA),and provide experimental basis for the prevention and treatment of VA after acute traumatic stress.Methods:(1)64 SD rats were chosen according to different time points after acute traumatic stress model to group.At different time points after operation(0 min,3 min,10 min,30 min,45 min,60 min,90 min),Each period,8 rats were sacrificed.They were divided into 8 groups: operative group,postoperative 0~3min,postoperative 3~10min,postoperative 10~30min,postoperative 30~45min,postoperative 45~60min,postoperative 60~90min and control group.(2)After creating acute traumatic stress model,we recorded heart rate,PR interval,QT interval,QTc interval,VA occurrence,VA score by II lead electrocardiogram(ECG).(3)HE stained to observe each rat myocardial cell morphology change.(4)Immunohistochemical stained to observe the change of Cx43 distribution and content.Results:(1)There was significant difference in heart rate.Compared with the rats before amputation,the heart rate which is increasing to the fastest in 0~3min after amputation 390.39±37.19 per/min(p<0.05).(2)After amputation,QT interval and QTc interval presented a characteristic of shortened.Compared with the rats before amputation,QT interval shorted to the shortest in 0~3min after amputation 0.41±0.07s(p<0.05),and QTc interval shorted to the shortest in 0~3min after amputation 0.147±0.022s(p<0.05).(3)50% of rats developed VA.We observed that there was a significant difference in the incidence of VA in each period of the rats(p<0.05),the most VA occured in first 0~3min after amputation.The VA incidence rate in first 0~3min after amputation was 35.4%.There were significant differences in the VA score of each period after amputation.The VA score in first 0~3min after amputation was the most which was 0.44±0.741.(4)The HE results showed: Compared with control group,the myocardial structure of objective group after amputation were without apparent change.(5)The immunohistochemical results showed: After amputation 0min,3min,10 min,30min,45 min of mycardial cell Cx43 presented apparent disorder.the amputation 3min changed the most obvious,the expression quantity of Cx43 reduced in the 3 min after amputation,and then trends to normal after 60 min.Conclusions: It was suggested that VA mainly occurred in the early stage of ATS and the highest degree of severity.In the early stage of ATS,the occurrence of VA accompanied QTc interval shortened,Cx43 distribution disorder and expression descendant.