右室流出道室性期前收缩的心电图特征及射频消融治疗

目的:探讨右室流出道室性期前收缩(室性早搏,室早)的心电图特征和评价单导管法消融单形性右室流出道室性早搏的有效性、安全性和实用性。方法:对52例心脏结构正常的右室流出道单形性室早的心电图特征进行分析并行单导管射频消融。采用起搏标测法,以起搏时与自发室性早搏形态波形态完全相同点为消融靶点。结果:右室流出道的室性早搏体表12导联心电图特征,呈完全性左束支阻滞形态,Ⅰ导联呈rs、m、QS及R型,aVR、aVL均呈QS型,Ⅱ、Ⅲ、aVF、V5~6导联均呈单向R波型,胸前导联R波移行区常在V3、V4导联之后。成功消融结果显示26例室早起源右室流出道间隔部:其中前间隔7例、中间隔5例、后间隔14例,游离壁21例:其中前游离壁6例、后游离壁15例,希氏束附近1例,肺动脉瓣下1例。消融即刻成功率94%(49/52),未成功的3例。手术操作时间30~150 min,X线曝光时间5~29 min。术后随访2~48个月无复发。结论:起源于右室流出道的室性早搏有其独特的心电图表现,单导管射频消融可有效、安全地消融心脏结构正常的右室流出道单形性室性早搏。

Electrocardiographic characteristics and radiofrequency catheter ablation in premature ventricular contractions originating from right ventricular outflow tract

AIM： To investigate the electrocardiographic characteristics and to evaluate the efficacy and safety of using a single catheter for radiofrequency catheter ablation in monomorphic premature ventricular contractions （PVCs） originating from right ventricular outflow tract （RVOI）. METHODS： Electrocar diographic characteristics and the results of radiofrequency catheter ablation were analyzed in 52 patients who had normal cardiac structure but monomorphic PVCs originating from right ventrieular outflow tract and were treated with a single catheter for radiofrequency catheter ablation. Using pace mapping method, the target points of ablation were the same pacing ventricular wave forms as monomorphic ventricular premature. RESULTS： The surface electrocardiogram of PVCs originating from the right outflow tract showed rs, m, QS or R wave on lead I, QS wave was seen on lead aVR and aVL and Tall R wave was seen on lead II, III, aVL, V5 and V6. Precordial lead R wave transition occurred on lead V3 or V4 or behind them. Successful ablation was achieved at sites of RVOT septum （ n = 26）, RVOT free wall （ n = 21 ）, His region （ n = 1 ） and the pulmonary valve （ n = 1 ）. Among the PVCs originating from the RVOT septum, seven were from the anterior wall, five from the mid-region and 14 from the posterior wall. For PVCs originating from the RVOT free wall, six were from the anterior wall and 15 from the posterior wall. Forty-nine of the 52 patients with PVCs were successfully abolished and immediate success rate of ablation was ～94% （49/52）. The procedure time was 30 -150 min and the fluoroscopic time was 5-29 min. No recurrence was found during follow-up. CONCLUSION： PVCs orizinating from right ventricular outflow tract show some specific electrocardiographic characteristics. Single-catheter radiofrequency catheter ablation could effectively and Safely treat normal cardiac structure patients who have normal cardiac structure but monomorphic PVCs originating from the right ventricular outflow tract.