右心室造影结合CARTO标测指引射频导管消融法洛四联症术后室性心动过速

Radiofrequency catheter ablation of ventricular tachycardia guided by right ventriculography and CARTO electroanatomic mapping in patients after cardiac surgery for tetralogy of Fallot

目的:应用右心室造影结合电解剖标测(CARTO标测)指引经盐水灌注射频导管消融法洛四联症术后室性心动过速(VT)5例。方法:5例患者中4例为男性,6～38岁,法洛四联症术后2～16年反复出现阵发性心悸,发病时体表心电图均表现为持续性VT且药物治疗无效,2例有晕厥史。均不同意放置埋藏式心脏复律除颤器(ICD)。应用右心室造影结合CARTO标测指引消融VT的方法如下:首先进行右心室造影明确右心室解剖及肺动脉瓣环位置,并作为解剖路标,在窦律时行右心室电压标测,标记低电压手术疤痕和室间隔补片区域,明确VT发生基质。而后心室程序电刺激诱发VT,如血流动力学稳定,则在VT时行拖带标测,确定并消融VT关键峡部;如血流动力学不稳定或不能诱发持续性VT,则在窦律时行起搏标测,在局部起搏时和VT有相同或相近的体表心电图并伴较长的刺激到QRS波时间的部位消融,并消融有晚电位或碎裂电位的电屏障区。结果:5例患者可诱发出6种形态VT,VT周长230～310 ms,5种为持续性VT,其中1种血流动力学不稳定;另1种为非持续性VT。3例患者在VT时标测和消融,2例患者在窦律下标测后消融。6种形态VT均为疤痕折返机制,6种VT均消融成功。随访12～30月,无VT复发。结论:右心室造影能明确法洛四联症术后右心室及肺动脉瓣环解剖结构,CARTO标测可以定位室间隔补片和外科手术疤痕,在明确这些VT发生基质基础上指引射频导管消融法洛四联症术后VT可取得较高的成功率。

AIM：To investigate the results of radiofrequency catheter ablation of ventricular tachycardia （VT） guided by right ventriculography and CARTO electroanatomic mapping in patients after cardiac surgery for tetralogy of Fallot （TOF）. METHODS： Included in the study were five patients （four males and one female, aged 6-38 years） who had palpitations and sustained VT for 2-16 years after cardiac surgery for TOF. Two patients had a history of syncope. All patients had been ineffectively treated with antiarrhythmic drugs. No ICD was implanted. Right ventricular angiography and CARTO electroanatomic mapping system were used for directing mapping and ablating VT. First, right ventriculography was conducted to show right ventricle anatomy and to locate the pulmonary valve. For mappable VT, the VT mapping techniques included activation, entrainment and voltage mapping using standard criteria, and radiofrequency energy was delivered to the sites. For unmappable VT, the site of origin was approximated by the site of pace mapping that generated QRS complexes similar to those of VT. Radiofrequency ablation was performed as linear lesions based on the location of the best pace map, the location of valvular anatomic boundaries and the substrate defined by the voltage mapping. The sites with late potential or fragmented potential were also ablated. Irrigated RF energy was delivered to all patients. RESULTS： Six morphologies of VT （five sustained and one nonsustained VT） were induced in five patients, including two morphologies of VT induced in one patient. Only one with nonsustained VT could be induced in one patient. The cycle lengths of VT were 230-310 msec. In three patients, mapping and ablation were performed during VT. In another two patients, mapping was performed during sinus rhythm because of unmappable VT. All 6 VT were caused by scar-related reentry and were eliminated successfully in five patients. During 12-30 months of follow-up, no VT recurred in the patients. CONCLUSION： Right ventricle and pulmonary artery valvular anatomy could well be demonstrated by right ventriculography. Surgical patch and scars could be located by CARTO system. Based on the matrix of arrhythmia, RF catheter ablation of VT in patients after cardiac surgery for TOF may have a high success rate and a low recurrence, especially of unmappable VT.