毁损家兔后房结通路对其房室结电生理特性的影响

目的 :观察手术切割毁损后房结通路对无房室结双径路 (DAVNP)现象的离体兔心房室结电生理特性的影响 ,进一步探讨房室结的整体电生理特性及消融改良房室结电生理特性的机制。方法 :家兔 9只 ,麻醉后从腔静脉抽出血液 2 0 0ml,与等量的台氏液混合后供灌流用。离体兔心采用Langendorf灌流装置 ,使用血液 台氏液灌流。以小号尖手术刀片进行切割 ,毁损后房结通路。分别测定手术切割前后的AH间期、房室结功能不应期 (AVN FRP)、房室结有效不应期 (AVN ERP)、房室结前传文氏点 (WCL)、HV间期、VA间期、房室结逆传文氏点周长 (VA WCL)、房室结逆传有效不应期 (VA ERP)。结果 :切割后房结通路明显影响房室结的电生理参数 ,表现为WCL、AVN FRP及VA WCL明显延长 (P <0 .0 5 )。结论 :在保持房室 1∶1传导的前提下切断家兔后房结连接 ,可导致房室结电生理出现明显变化。本实验结果为临床射频消融改良房室结功能提供了一定的理论依据

Effect of Dissection of Posterior Atrionodal Input on the Electrophysiologyof Atrioventricular Node in Isolated Rabbit Heart

Abstract:To observe the effect of surgical dissection of posterior atrionodal input (PANI) on the electrophysiology of atrioventricular node(AVN) in isolated rabbit heart and investigate deeply the electrophysiological characteristics of AVN and the mechanism of modification of AVN electrophysiology by ablation. Methods:Bloods were taken transvenously from 9 anesthesed rabbits and mixed with equal volume of Tyrode's solution. The isolated hearts were perfused with blood Tyrode's solution using langendorf appraut. PANI was surgically dissected with tiny surgical blade. The electrophysiological parameters, including AH interval, functional refractory period of AVN(AVN FRP), effective refractory period of AVN(AVN ERP), Wenckbech cycle length of AVN (WCL), His Ventricle interval, Ventricle Atrial interval, Wenckbech cycle length of ventricle atrium conduction (VA WCL) and fonctional refractory period of retrograde ventricle atriumconduction(VA FRP) were measured before and after the dissection. Results:It was showed that dissection of PANI could affect the electrophysiology of AVN significantly. WCL, AVN FRP and VA WCL prolonged significantly after the dissection. Conclusion:The dissection of PANI while maintaining 1∶1 AV conduction could lead to change in electrophysiological characteristics of AVN in perfused isolated rabbit heart. The results of this experiment, to some extent, provide theoretic basis for modulation of electrophysiological characteristics of AVN in clinical practice.