Lokhandwala Y Y, Smeets J L, vd Steld B, Narula D D, Stockman D, Wellens H J
Department of Cardiology, Academic Hospital, Maastricht, The Netherlands.
Indian Heart J. 1996 Mar-Apr;48(2):138-44.
Precise localization of accessory pathways (APs) is crucial to minimize radiofrequency (RF) energy applications in the Wolff-Parkinson-White (WPW) syndrome. Although several markers have been described for identifying APs, no gold standard has thus far been established. The present study attempted to validate the hypothesis that an early intrinsic deflection (ID) would be identifiable in the unipolar ventriculogram, if this was recorded at or near the site of endocardial breakthrough of the AP. The electrograms of 23 patients with the WPW syndrome who underwent RF ablation were analysed using a computer-based system. A total of 50 electrograms (19 successful and 31 unsuccessful RF energy applications) were studied. The downstroke of the unipolar ventriculogram was measured at 1 msec intervals for the dV/dt; the maximal dV/dt (the most rapid segement of the downstroke) was considered as the ID. The following parameters were found to differentiate between successful and unsuccessful RF ablation attempts: (i) Timing of the ID relative to the delta wave onset (ID-delta = plus 11 +/- 21 msec versus minus 18 +/- 22 msec, p < 0.001). (ii) Timing of the ID relative to the onset of the unipolar ventriculogram (Vu-ID = 14 +/- 7 msec versus 29 +/- 15 msec, p < 0.001). (iii) Maximal dV/dt in the initial 20 msec of the unipolar ventriculogram (367 +/- 146 microV/msec versus 207 +/- 97 microV/msec, p < 0.001). The other parameters (probable AP potential, bipolar ventriculogram timing, continuous electrical activity, unipolar signal morphology) were not helpful in this regard. Hence, the identification of the ID and measurement of its timing is helpful in localising overt APs for successful delivery of RF energy.
精确确定旁路（APs）的位置对于减少 Wolff-Parkinson-White（WPW）综合征中射频（RF）能量的应用至关重要。尽管已经描述了几种用于识别 APs 的标记物，但迄今为止尚未建立金标准。本研究试图验证这样一个假设：如果在 AP 的心内膜突破部位或其附近记录单极心室电图，那么早期固有偏转（ID）将是可识别的。使用基于计算机的系统分析了 23 例接受射频消融的 WPW 综合征患者的心电图。共研究了 50 份心电图（19 次成功和 31 次不成功的 RF 能量应用）。以 1 毫秒的间隔测量单极心室电图的下降支以计算 dV/dt；最大 dV/dt（下降支最快的部分）被视为 ID。发现以下参数可区分成功和不成功的射频消融尝试：（i）ID 相对于δ波起始的时间（ID-δ = +11±21 毫秒对 -18±22 毫秒，p < 0.001）。（ii）ID 相对于单极心室电图起始的时间（Vu-ID = 14±7 毫秒对 29±15 毫秒，p < 0.001）。（iii）单极心室电图最初 20 毫秒内的最大 dV/dt（367±146 微伏/毫秒对 207±97 微伏/毫秒，p < 0.001）。其他参数（可能的 AP 电位、双极心室电图时间、连续电活动、单极信号形态）在这方面没有帮助。因此，识别 ID 并测量其时间有助于定位明显的 APs，以便成功输送 RF 能量。
