Lai Dakun, Liu Chenguang, Eggen Michael D, Iaizzo Paul A, He Bin
Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
IEEE Trans Inf Technol Biomed. 2010 Nov;14(6):1318-26. doi: 10.1109/TITB.2010.2051448. Epub 2010 May 27.
Localization of the initial site of cardiac ectopic activity has direct clinical benefits for treating focal cardiac arrhythmias. The aim of the present study is to experimentally evaluate the performance of the equivalent moving dipole technique on noninvasively localizing the origin of the cardiac ectopic activity from the recorded body surface potential mapping (BSPM) data in a well-controlled experimental setting. The cardiac ectopic activities were induced in four well-controlled intact pigs by either single-site pacing or dual-site pacing within the ventricles. In each pacing study, the initiation sites of cardiac ectopic activity were localized by estimating the locations of a single moving dipole (SMD) or two moving dipoles (TMDs) from the measured BSPM data and compared with the precise pacing sites (PSs). For the single-site pacing, the averaged SMD localization error was 18.6 ± 3.8 mm over 16 sites, while the averaged distance between the TMD locations and the two corresponding PSs was slightly larger (24.9 ± 6.2 mm over five pairs of sites), both occurring at the onset of the QRS complex (10-25 ms following the pacing spike). The obtained SMD trajectories originated near the stimulus site and then traversed across the heart during the ventricular depolarization. The present experimental results show that the initial location of the moving dipole can provide the approximate site of origin of a cardiac ectopic activity in vivo, and that the migration of the dipole can portray the passage of an ectopic beat across the heart.
确定心脏异位活动的初始部位对于治疗局灶性心律失常具有直接的临床益处。本研究的目的是在一个严格控制的实验环境中，通过记录体表电位标测（BSPM）数据，对等效移动偶极子技术在无创定位心脏异位活动起源方面的性能进行实验评估。通过在四个严格控制的完整猪的心室内进行单部位起搏或双部位起搏来诱发心脏异位活动。在每项起搏研究中，通过从测量的BSPM数据估计单个移动偶极子（SMD）或两个移动偶极子（TMD）的位置来定位心脏异位活动的起始部位，并与精确的起搏部位（PS）进行比较。对于单部位起搏，在16个部位上，SMD的平均定位误差为18.6±3.8毫米，而TMD位置与两个相应PS之间的平均距离略大（在五对部位上为24.9±6.2毫米），两者均发生在QRS波群开始时（起搏尖峰后10 - 25毫秒）。获得的SMD轨迹起始于刺激部位附近，然后在心室去极化过程中穿过心脏。目前的实验结果表明，移动偶极子的初始位置可以提供体内心脏异位活动的大致起源部位，并且偶极子的迁移可以描绘异位搏动在心脏中的传播过程。
