非接触球囊标测指导血流动力学不稳定性或非持续性室性心动过速的射频消融

Noncontact endocardial mapping to guide ablation for hemodynamically unstable or nonsustained ventricular tachycardia

目的探讨非接触球囊标测在指导血流动力学不稳定性或非持续性室性心动过速(室速)射频消融中的作用。方法17例室速患者,年龄50岁±9岁,经心室刺激诱发血流动力学不稳定性或非持续性室速后,使用非接触标测系统ENSITE3000标测室速的出口和(或)慢传导区,然后使用温控大头导管在室速出口作环形消融或横跨慢传导区进行线性消融。结果17例患者共诱发18次室速,周长为336MS±58MS。15例患者可确定室速的出口,为QRS波前10MS±16MS;其中5例是心肌梗死后室速,9例为右室流出道室速。5例心肌梗死后室速均可确定舒张期慢传导区,最早的心内膜舒张期电活动在QRS波前60·1MS±42·6MS。3例非持续性室速均可确定最早的心室激动点。18次室速中15次消融成功,1例没有进行消融,2例消融失败。结论非接触球囊心内膜标测能成功指导血流动力学不稳定性或非持续性室速的射频消融。

Objective To determine the feasibility and assess the validity of noncontact endocardial mapping to guide ablation of hemodynamically unstable or nonsustained ventricular tachycardia （VT） . Methods Noncontact mapping permitted individual-beat analysis of ventricular arrhythmias. Threedimensional electroanatomical mapping allowed detailed reconstruction of a chamber geometry and activation sequence. Eighteen hemodynamically unstable or nonsustained VTs were induced （ cycle length： 336 ms ± 58 ms） in 17 patients and mapped by noncontact mapping using an EnSite 3000 system performed for the guidance of catheter ablation. Results Three patients were mapped during premature ventricular complexes （PVCs） because sustained VT could not be induced. Analysis of the archived noncontact activation maps was performed to identify the exit site and/or the diastolic pathway of the VT reentry circuit. The endocardial exit sites 10 ms ± 16 ms before QRS were defined in 9 right ventricular outflow tract （RVOT） and 5 ischemic VTs. The diastolic pathway was identified in 5 ischemic VTs. The earliest endocardial diastolic activity preceded the QRS onset by 60. 1 ms ± 42. 6 ms. The earliest activation sites were identify in 3 patients with nonsustained VTs or PVCs. Radiofrequency current was applied around the exit site or to create a line of block across the diastolic pathway. Catheter ablation was performed in 17/18 （94%） VTs and 15/ 17 （88%） VTs was successfully ablated. Two （67%） of the three patients with nonsustained VTs were mapped and successfully ablated during PVCs. Catheter ablation was not performed in 1 patient （ peri-Hisian VT） and was unsuccessful in 2 patients. Conclusion Noncontact endocardial mapping is able to be used to guide ablation of untolerated or nonsustained VTs.