快频率依赖性室房逆传左侧隐匿性房室旁道参与的心动过速及射频导管消融

目的探讨快频率依赖性室房逆传特性左侧隐匿性房室旁道的电生理特点及射频消融。方法对8例心电图显示窄QRS波群心动过速的患者行电生理检查，分析房室、室房传导情况、心动过速特点、旁道定位，并行射频消融。结果8例患者均证实存在快频率依赖性室房逆传特性左侧隐匿性旁道，在较慢频率起搏右心室时旁道逆传发生阻滞，而以中等频率起搏时表现为间断旁道逆传，较快频率起搏时才表现为旁道1：1传导且均诱发了房室折返性心动过速，于快频率心室刺激下标测消融靶点，消融均获成功。结论左侧隐匿性房室旁道有时可发生快频率依赖性室房逆传现象，并伴发房室折返性心动过速，在射频消融中需注意分辨，以免漏诊。

Radiofrequency Catheter Ablation of Left Concealed Atrioventricular Accessory Pathway with Rapid Rate Dependent Ventriculoatrial Conduction

Objective To investigate electrophysiological characteristics of left concealed atrioventrieular accessory pathway （AP） with rapid rate dependent ventriculoatrial conduction （VAC） and radiofrequency catheter ablation（RFCA）. Methods 8 patients with narrow QRS complex tachycardia underwent electrophysiological study. Atrioventricular conduction, VAC, features of tachycardia and site of AP were evaluated and RFCA was performed. Results All cases had left concealed atrioventricular AP with rapid rate dependent VAC. VAC of AP did not occur during slow right ventricular pacing （RVP）. As the pacing rate increased, VAC of AP appeared intermittently. Rapid RVP resulted in 1：1 VAC of AP and induced atrioventricular reentrant tachycardia. All AP were ablated successfully after mapping target site during rapid RVP. Conclusion Left concealed atrioventricular AP may manifested as rapid rate dependent VAC and induce atrioventrieular reentrant tachycardia.