非间隔部三尖瓣环起源局灶性房性心动过速的临床及电生理特点

Clinical characteristics and electrophysiological features in patients with focal atrial tachycardia origi- nating from the nonseptal region of tricuspid annulus

目的总结非间隔部三尖瓣环起源局灶性房性心动过速（房速）的临床及电生理特点。方法收集2005年8月至2014年10月问因房速于阜外医院心律失常中心行射频导管消融的患者资料，并详细分析起源于非间隔部三尖瓣环房速患者的临床资料。结果318例局灶性房速患者中，16例（5．0％）房速被证实起源于非间隔部三尖瓣环，其中大部分（9／16例）房速起源点分布在三尖瓣环6—8点。随房速起源点沿三尖瓣环由6点顺时针至12点，aVL、aVR导联由正向变为负向，下壁导联由负向变为正向，胸前导联V5-6由负向变为正向。右心房内的传导顺序及心房间的优先激动途径决定了其心房波的形态特点。结论非间隔部三尖瓣环起源的局灶性房速的比例较低，以三尖瓣环6～8点处居多；不同三尖瓣环部位的房速有其特征性心房波形态。

Objective To observe the clinical characteristics and electrophysiological features in pa- tients with focal atrial tachycardia （AT）originating from the nonseptal region of tricuspid annulus （TA）. Meth- ods From August 2005 to October 2014, the patients underwent successful radiofrequency catheter ablation （RFCA） for focal AT were enrolled in the study,and the clinical and electrophysiological data of patients with a TA focus were reviewed. Result Among the 318 patients with focal AT, 16 （5.03%）patients had focal AT originating from nonseptal region of TA. Most of the TA focus （9/16 cases）were localized in the segment of the TA between 6：00 and 8：00. Along with the TA focus clockwise from 6：00 to 12：00,the P wave morphology during AT changed from positive to negative in leads aVL and aVR, from negative to positive in inferior leads, and from negative to positive in leads V5-6. The P wave morphology may be determined by the right atrial con- duction and preferential interatrial conduction. Conclusion The nonseptal region of TA is an uncommon origin of focal AT, and most of the TA focus were localized in the segment of the TA between 6 ： 00 and 8 ： 00. The TA focus from different segments have characterized P wave morphologies.