心肌内心电图监测和诊断大鼠心脏移植术后的排斥反应

The experimental study of IMEG in monitoring acute allograft rejection

目的寻找监测和诊断心脏移植术后排斥反应的敏感心电指标。方法建立40只改良Ono法大鼠腹部异位心脏移植模型,其中对照组(同基因大鼠心脏移植)10只,实验组(异基因大鼠心脏移植)30只。在心脏移植术中,于供心右室流出道的心肌处缝置一单极的心表起搏导线,描记心肌内心电图,测量QRS波波幅和心率。对照组大鼠在术后第7天处死,实验组分别在术后3、5、7 d处死,取移植心组织进行病理检查。结果对照组大鼠的QRS波波幅在手术2 d后趋于稳定,术后3、5、7 d各时点间的QRS波波幅差异不显著;实验组大鼠术后QRS波波幅呈进行性下降,术后3、5、7 d各时点间比较,其波幅的降低幅度差异有统计学意义。对照组和实验组大鼠术后心率变化无明显规律,两组间比较,差异无统计学意义。心肌组织病理检查显示排斥反应的分级与QRS波波幅下降有明显的相关性。结论心肌内心电图描记是监测和诊断心脏移植术后排斥反应的有效方法,QRS波波幅是诊断和监测排斥反应发生的敏感指标,严重排斥反应发生时QRS波波幅明显下降。心率的变化不是监测心脏排斥反应的可靠指标。

Objective To study some sensitive electrophysiological parameters in surveillance of allograft rejection. Methods Forty rats underwent heterotopic heart transplantations. IMEG was recorded by an epicardiac unipolar pacing lead fixed at the right ventricular outflow tract. QRS amplitude and heart rate were determed daily in 10 syngeneic and 30 allogeneic transplants. Syngeneic transplants were killed at 7 th postoperative day, and allogeneic transplants killed at 3 rd, 5 th and 7 th postoperative day. Histopathologic studies were performed at every transplanted heart. Results In syngeneic group, QRS amplitude kept constant after the transplantation while no significant differences were observed at the 3 rd, 5 th and 7 th postoperative day. QRS amplitude was dropped obviously in allogeneic group after the first two postoperative days whereas significant differences were observed at the rejecting and non-rejecting hearts. Conclusions IMEG is a valid method to monitor acute allograft rejection. QRS amplitude is a more sensitive electrophysiological parameter to diagnose severe rejections than heart rate, while mild rejections were not detected by this method.