室房逆传的再探讨

目的 探讨在体房室结无室房逆传或逆传功能明显低于房室顺传的机制。方法 对128例心脏介入性诊疗术患者，分别作心房、心室刺激，观察经房室结顺传及室房逆传的电生理特征。结果 除21例三度房室传导阻滞外，107例房室顺传文氏点大于150次／min；有经房室结室房逆传者12例（11．2％），其中室房逆传文氏点10例小于130次／min，2例为130次／min。95例（88．8％）及21例三度房室传导阻滞者均无室房逆传。结论 绝大多数在体房室结固有逆传功能明显低于房室顺传，或呈单向传导。房室旁道和／或房室结逆传快径路是室房逆传良好的主要原因及形成阵发性室上性心动过速等病症的根本机制。

Re-evaluation of ventrioatrial conduction

Objective To re_evaluate electrophysiological characteristics of atrioventricular and ventrioatrial conduction and to elucidate mechanism of lack or significant decrease of ventrioatrial conduction compared with atrioventricular conduction. Methods One hundred twenty eight patients,underwent cardiac intervention,atrial and ventricular stimulations were performed to observe electrophysilogical characteristics of atrioventricular and ventrioatrial conduction during interventional procedures. Results Atrioventricular conduction Wenckeback point was below 150 beat per minute in 107 of 128 patients.Twelve patients(11.2%) had ventrioatrial conduction,but Wenckeback point was below 130 beat per minute except 2 patients with Wenckeback point of 130 beat per minute.Other 95 patients(88.8%)and 21 patients with complete atrioventicular conduction block had no ventrioatrial conduction. Conclusion Intrinsic atrioventricular conduction ability is poor,representing unidirectional conduction in majority of cases. Atioventricular accessory pathway and /or fast pathway of atrioventricular node are major causes of good ventrioatrial conduction and also essential mechanism of paroxysmal superventricular tachycardia.