Tung Stanley, Soejima Kyoko, Maisel William H, Suzuki Makoto, Epstein Laurence, Stevenson William G
Cardiovascular Division, Department of Internal Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
J Am Coll Cardiol. 2003 Jul 2;42(1):110-5. doi: 10.1016/s0735-1097(03)00563-1.
The goal of this study was to assess entrainment for distinguishing far-field potentials (FFP) due to depolarization of tissue at a distance from the mapping catheter from the local potential (LP) due to depolarization of tissue at the catheter electrode during mapping of ventricular tachycardia (VT).
Electrograms with multiple peaks commonly complicate mapping and identification of catheter ablation targets in infarcts.
Retrospective analysis of catheter mapping data from eight patients with prior infarction was performed to evaluate multipotential electrograms at sites where pacing entrained VT. Potentials that were visible and not altered during pacing were defined as FFP. Potentials obscured by the pacing stimulus were designated possible LPs. The criteria for FFP were then assessed in a second cohort of five patients.
At 32 of 39 (82%) sites with multiple potentials, entrainment identified one of the potentials as an FFP. Radiofrequency ablation, assessed at 15 sites, reduced the amplitude of LPs by 62%, without significant effect on FFP amplitude. At 56% of sites with multiple potentials, measuring the postpacing interval to an FFP would lead to erroneous classification of the site location relative to the reentry circuit. In prospective evaluation, double potentials were identified at 77 sites in infarcts; entrainment demonstrated an FFP at 66 (86%) sites.
Far-field potentials are common during mapping in infarcts. Many can be distinguished from local potentials by entrainment, improving the accuracy of mapping.
本研究的目的是评估在室性心动过速（VT）标测期间，通过拖带技术区分距标测导管一定距离处组织去极化产生的远场电位（FFP）与导管电极处组织去极化产生的局部电位（LP）。
具有多个波峰的心电图通常会使梗死灶中导管消融靶点的标测和识别变得复杂。
对8例既往有心肌梗死患者的导管标测数据进行回顾性分析，以评估拖带VT时起搏部位的多电位心电图。起搏期间可见且未改变的电位定义为FFP。被起搏刺激掩盖的电位指定为可能的LP。然后在另一组5例患者中评估FFP的标准。
在39个有多个电位的部位中的32个（82%），拖带技术将其中一个电位识别为FFP。在15个部位进行的射频消融使LP的幅度降低了62%，而对FFP幅度无显著影响。在有多个电位的部位中，56%的部位测量到FFP的起搏后间期会导致相对于折返环的部位定位错误分类。在前瞻性评估中，在梗死灶的77个部位识别出双电位；拖带技术在66个（86%）部位显示出FFP。
远场电位在梗死灶标测期间很常见。许多远场电位可通过拖带技术与局部电位区分开来，提高了标测的准确性。
