University of Michigan Medical Center, Ann Arbor, Michigan, USA.
J Cardiovasc Electrophysiol. 2010 Sep;21(9):1017-23. doi: 10.1111/j.1540-8167.2010.01756.x.
In patients with prior infarction, isolated potentials (IPs) during sinus rhythm reflect fixed scar and often indicate sites critical for ventricular tachycardia (VT). The purpose of this study was to determine the value of IPs in conjunction with pace-mapping to guide VT ablation in patients with various types of nonischemic cardiomyopathy.
Mapping and ablation of VT were performed in 35 consecutive patients (26 men, age 55 ± 13 years, ejection fraction 0.31 ± 0.14) with VT and various etiologies of nonischemic cardiomyopathy. Pace-mapping was performed at sites with low voltage. Radiofrequency energy was delivered at sites with concealed entrainment or matching pace-maps.
One hundred ninety-five VTs (mean cycle length 363 ± 88 ms) were induced. Sites with prespecified ablation criteria displaying IPs during sinus rhythm were recorded in 21 of 35 patients (60%, IP-positive). In these patients, a total of 216 sites meeting prespecified ablation criteria were identified and 146 of 216 sites (68%) displayed IPs. Fifteen of 21 IP-positive patients (71%) no longer had inducible VT after ablation. In 14 of 35 patients, no sites with IPs where prespecified ablation criteria were met were identified (IP-negative) despite combined endocardial and epicardial mapping in 7 of 14 patients. Only 1 of 14 IP-negative patients (7%) no longer had inducible VT at the end of the ablation procedure. During a mean follow-up of 18 ± 13 months, 14 of 21 IP-positive patients (67%) remained arrhythmia-free, compared to 1 of 14 IP-negative patients (7%; P < 0.01). Half of the IP-negative patients had major adverse events due to recurrent arrhythmias, compared to none in IP-positive patients.
IPs in conjunction with pace-mapping are helpful for identifying critical isthmus areas for ablation of VT in patients with various types of nonischemic cardiomyopathy. Patients with nonischemic cardiomyopathy in whom the arrhythmogenic substrate is characterized by IPs have a more favorable outcome than patients in whom IPs are absent.
在既往梗死的患者中，窦性心律时的孤立电位（IP）反映了固定的瘢痕，通常提示与室性心动过速（VT）相关的关键部位。本研究旨在确定 IP 与起搏标测相结合在各种类型非缺血性心肌病患者中指导 VT 消融的价值。
连续 35 例 VT 合并各种非缺血性心肌病病因的患者（男 26 例，年龄 55 ± 13 岁，射血分数 0.31 ± 0.14）进行 VT 标测和消融。在低电压部位进行起搏标测。在心内和心外联合标测下隐匿性夺获或匹配起搏图部位给予射频能量。
共诱发 195 次 VT（平均周长 363 ± 88 ms）。在 35 例患者中有 21 例（60%，IP 阳性）窦性心律时记录到符合预设定消融标准的部位存在 IP。在这些患者中，总共确定了 216 个符合预设定消融标准的部位，其中 146 个（68%）部位存在 IP。21 例 IP 阳性患者中有 15 例（71%）消融后不再诱发出 VT。在 35 例患者中有 14 例（IP 阴性），尽管在 7 例患者中进行了心内和心外联合标测，仍未发现符合预设定消融标准的 IP 阳性部位。14 例 IP 阴性患者中只有 1 例（7%）在消融结束时不再诱发出 VT。平均随访 18 ± 13 个月后，21 例 IP 阳性患者中有 14 例（67%）保持无心律失常，而 14 例 IP 阴性患者中有 1 例（7%）（P < 0.01）。一半的 IP 阴性患者因心律失常复发而发生重大不良事件，而 IP 阳性患者无一例发生。
IP 与起搏标测相结合有助于识别各种类型非缺血性心肌病患者 VT 消融的关键峡部区域。心律失常基质以 IP 为特征的非缺血性心肌病患者的预后优于 IP 阴性患者。
