选择性切除左侧星状神经节下部对心房颤动犬快速心室率的影响

Effects of selectively resecting the lower half of stellate ganglion on fast ventricular rate in canines with persistent atrial fibrillation

目的研究切除左侧星状神经节(left stellate ganglion,LSG)下部对心房颤动(房颤)维持时快速心室率的影响,并探究其机制。方法成年健康雄性比格犬12只,体重15～25 kg。随机分为2组(对照组和实验组),每组各6只。对照组:只应用左心房快速起搏建立犬持续性房颤模型,不做其他处理。实验组:应用左心房快速起搏建立犬持续性房颤模型,房颤模型建立成功后再切除犬LSG下部。房颤模型建立成功后,在麻醉前、麻醉后、LSG切除后30 min及1个月,分别记录犬的心室率;并在LSG切除后1个月、处死犬之前,测定犬的房室结(atrioventricular node,AVN)前传有效不应期(effective refractory period,ERP)。结果左心房快速起搏3～6周后,所有犬均成功构建成稳定的持续房颤模型。切除LSG下部30 min后(对照组不切除,仅观察30 min):对照组犬的平均心室率约为(144.5±4.2)次/min,实验组犬的平均心室率约为(121.5±8.7)次/min(P<0.001);切除LSG下部1个月后(对照组不切除,仅观察1个月):对照组犬的平均心室率约为(139.2±5.6)次/min,实验组犬的平均心室率约为(106.5±4.9)次/min(P<0.001)。切除LSG下部1个月后,实验组犬的AVN前传ERP较对照组犬的AVN前传ERP明显延长[(265.6±7.8)ms vs.(251.1±4.6)ms,P=0.003]。结论切除LSG下部可以有效减慢房颤犬的快速心室率,其机制之一可能就是通过延长房颤犬的AVN前传ERP。

Objective To determine the effects of resecting the lower half of left stellate ganglion(LSG) on fast ventricular rate(VR) in persistent atrial fibrillation(AF) and its mechanism. Methods Twelve mature healthy male beagle dogs(15–25 kg) were studied. They were randomly divided into two groups(an experimental group and a control group, 6 dogs in each group). The control group were merely performed with rapid left atrial pacing to induce persistent AF. The experimental group were disposed with rapid left atrial pacing and received resection of the lower half of LSG after the persistent AF was documented. Simultaneously the ventricular rates were monitored separately before anesthesia, after anesthesia, 30 minutes and one month after LSG resection. The forward passing effective refractory period(ERP) of the canine atrioventricular node(AVN) was also measured. Results Each dog was documented with persistent AF after 3–6 weeks’ left atrial pacing. After resecting the lower half of LSG for 30 minutes(the control group was only observed for 30 minutes without LSG resection), the average VR of the control group attained 144.5±4.2 beats/min, while that of the experimental group was 121.5±8.7 beats/min(P<0.001). After resecting the lower half of LSG for one month(the control group was observed for one month without LSG resection), the average VR of the control group was 139.2±5.6 beats/min, while that of the experimental group was 106.5±4.9 beats/min(P<0.001).Meantime, the forward passing ERP of AVN of the experimental group was significantly prolonged than that of the control group(265.6±7.8 ms vs. 251.1±4.6 ms, P=0.003). Conclusion Resection of the lower half of LSG is efficient in reducing VR in canines with persistent AF, one of the mechanisms of which may be prolonging the forward passing ERP of AVN.