单导管射频消融治疗主肺动脉干室性早搏／室性心动过速临床观察

目的探讨起源于主肺动脉干（MSPA）室性早搏（PVCs）/室性心动过速（VT）的心电图特征、标测方法及单导管射频消融治疗的疗效与安全性。方法选取经肺动脉造影证实起源于MSPA的PVCs／VT患者12例（MSPA组）以及右心室流出道（RVOT）前间隔起源的PVCs／VT患者59例（RVOT组），均采用单导管常规标测技术进行标测、消融。比较分析两组患者心电图特征，随访MSPA组患者的疗效。结果MSPA组患者体表心电图具有下壁导联R波振幅高以及胸前导联移形较早（多位于V2～V3）的特点，其有效靶点高电压（8V）可起搏心室，并与自发PVCs/VT的QRS波形12导联完全相同，有效靶点心室电位较PVCs／VT体表心电图QRS波起始点提早（33.91±3.69）ms，10例可记录到远场A、V波，6例可记录到融合或分离的尖峰或碎裂电位。所有消融治疗均成功，无并发症发生，随访期间无复发病例。结论起源于MSPA的PVCs／VT并非罕见．单导管标测及消融安全、有效．

Single-catheter approach of radiofrequency ablation in treatment of idiopathic premature ventricular contractions originating from the main stem of pulmonary artery

Objective To evaluate the safety and efficacy of single-catheter approach to radiofrequency ablation （SCARF） in treatment of idiopathic premature ventricular contractions （PVCs） and/or ventricular tachycardia （VT） originating from the main stem of pulmonary artery （MSPA）. Methods Twelve patients with PVCs and/or VT originating from MSPA diagnosed by pulmonary artery angiogram and 59 patients with PVCs and/or VT originating from right ventricular outflow tract were included in the study. Using single catheter approach, electrophysiological study, pacing mapping and/or activation mapping and catheter ablation were performed in two groups. ECG characteristics were compared between the groups; and the long-term outcome of MSPA group was followed up. Results Surface ECG of PVCs/VT originating from MSPA showed a higher R waves amplitude in the inferior leads and earlier transition in precordial leads than those of right ventricular outflow tract anteroseptal site PVCs/VT. The pacing mapping was successfully completed by high voltage, and QRS complex of pacing mapping was completely with the QRS complex of clinical PVCs/VT. The electrogram at target site was 33.91 ± 3.69（ 30-45 ）ms earlier than that of the QRS complex of clinical PVCs/VT with small atrial and large ventricular electrogram in 10 patients, and a fusion of spike or fractionated potential before the ventricular electrogram in 6 patients. Operations were performed smoothly with no ablation related complications. No recurrences were found during 3 - 19 month-following up. Conclusion The approach of single catheter ratiofrequency ablation is safe and effective for patients with PVCs/VT originating from MSPA.