目的 探讨左右冠窦交界处起源室性期前收缩（室性早搏）的心电图特点及其导管消融治疗。方法 应用三维标测系统对两例左心室流出道室性早搏患者进行心内电生理检查和导管消融。结果 电生理检查示两例室性早搏均起源于左右冠窦交界处。体表心电图特点为胸前导联移行较早（V3导联之前），V1导联为降支带切迹的QS型、V1-V3导联之一呈qrS型，或无特征性形态。导管贴靠于左右冠窦之间，或贴靠于两窦交界的左冠窦侧，两例室性早搏均获得完全消除。结论 起源于左右冠窦交界处室性早搏的体表心电图有特征性表现，也可无特征性形态;采用适当的导管贴靠方法可以成功消融。

Objective To explore the electrocardiographic characteristics and catheter ablation of ventricular ectopic beats originating from the junction of left and right coronary sinuses of Valsalva in the aorta. Methods Electrocardiographic examination and ablation were performed under the guidance of three dimensional mapping systems in two patients with ectopic beats originating from left ventricular outflow tract. Results Ectopic beats were mapped to originate from the junction of left and right coronary sinuses of Valsalva in both patients. The electrocardiograms showed early precordial transition of QRS complex prior to lead V3 in two patients, the notching QS morphology in lead V1, the qrS pattern in leads V1-V3 in one patient and non-specific morphology in the other patient. Subsequent ablation by positioning the irrigated catheter at the junction of two sinuses of Valsalva or at the left side of the junction (in left coronary sinus of Valsalva) successfully abolished ectopic beats in two patients. Conclusion There may be or may not be characteristic electrocardiographic findings for ventricular ectopic beats originating from the junction of left and right coronary sinuses of Valsalva in the aorta, and catheter ablation could abolish them successfully by proper catheter placement.