迷走神经张力型房室传导不应期显著延长的电生理特点及预后分析

The prognosis and characteristics of significantly prolonged atrio-ventricular refractory in patients with high parasympathetic tone

目的 探讨因迷走神经张力过高而引起的房室传导不应期(AVERP)显著延长的电生理特点及预后.方法 对从284例电生理检查中检测出的21例(7.4%)进行静注阿托平前后及随访分析.结果 21例文氏点,2:1阻滞点明显降低(分别(98±12)次/分,(145±13)次/分)及ERP显著延长(502±38)ms.调搏中His束图示11例A-H延长或阻滞,推注阿托品后AV传导能力显著改善,文氏点、2:1阻滞点和AVERP三项指标分别为(148±27)次/分,>170次/分和(224±34)ms.随访3～8年其电生理特点与静注阿托平前无显著差异.仅2例因头晕和乏力安置了心脏起搏器.结论 迷走张力型AV不应期延长在临床上常见,但易被忽略,房室传导能力的减弱主要受迷走神经张力的影响而出现在His束以上部位,也可呈交替文氏现象,但AVERP显著延长是一功能性传导异常现象,虽有轻度加重趋势,但预后一般良好.

Purpose To analyze the electrophysiological characteristics and prognosis of the significantly prolonged atrio-ventricu-lar effective refractory period(AVERP) caused by high parasympathetic tone. Methods We chose 21 cases (7. 4%) with long AVERP from 284 patiens and analyzed them before and after atropine test as well as 3 - 8 years' follow up. Results The Wenckebachs AV block rate and 21 AV block rate of all patients was significantly lowered(98±12)bpm and (145±13)bpm respectively) and the AVERP prolonged(502±38)ms. 19 cases demonstrated and A-H delay or A-H block during atrial pacing. The ability of AV conduction was obviously improved after intravenous injection of atropine (P<0. 01). The Wenckbachs',2:l block rate and AVERP were (148±27)bpm,170 bpm and (224±34)ms respectively. The electrophysiological characteristics of follow up periods had no significant difference with that of before atropine test. Only 2 patients implanted pacemakers because of dizziness and fatigue. Conclusion The vagus induced long AVERP is a common clinical phenomenon but often being neglected. The AV delay is located above His band so that it can be controlled by the vagal activity. Although there is a trend of even longer AVERP during follow up periods,the prolonged ERP is a functional conduction phenomenon and have a benign prognosis.