On the efficiency and accuracy of the single equivalent moving dipole method to identify sites of cardiac electrical activation.
On the efficiency and accuracy of the single equivalent moving dipole method to identify sites of cardiac electrical activation.
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DOI：
10.1007/s11517-015-1437-x
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发表时间：
2016-10
影响因子：
3.2
通讯作者：
Armoundas AA
中科院分区：
文献类型：
--
作者：
Sohn K;Armoundas AA
我们提出了一种指导射频导管消融手术的算法。该算法采用单等效移动偶极子 (SEMD) 来模拟心电活动。本研究的目的是调查心动周期中的最佳时刻以及准确估计起搏部位位置所需的心跳次数。我们通过对心室心外膜表面起搏并根据记录的体表电位反向估计起搏电极的位置来评估该算法。将两个起搏电极阵列缝合在猪的右心室和左心室心外膜表面。通过电极以多种速率（120-220 bpm）顺序对心脏进行起搏，并记录来自 64 根导联的体表心电图信号以进行 SEMD 估计。我们评估了心动周期中每个时刻估计的电极间距离和SEMD方向的组合误差，发现当体表心电信号的归一化均方根（RMSn）值达到其最大值的15%时误差最小。与最早激活时间 (EAT) 相比，当估计为 15% RMSn 时，SEMD 位置的逐搏变化显着降低 (p<0.001)。此外，随着用于估计中位心跳的心跳次数的增加，估计的电极间距离误差的 5%–95% 区间呈指数下降。当心跳次数为4次或以上时，5%~95%间隔小于3.5毫米（常用导管的直径）。总之，SEMD 估计的最佳时间是 RMSn 的 15%，并且在该时刻，根据 4 次心跳估计的中位心跳与适合导管消融手术的 SEMD 位置的逐次心跳变异性相关。
We have proposed an algorithm to guide radio-frequency catheter ablation procedures. This algorithm employs the single equivalent moving dipole (SEMD) to model cardiac electrical activity. The aim of this study is to investigate the optimal time instant during the cardiac cycle as well as the number of beats needed to accurately estimate the location of a pacing site. We have evaluated this algorithm by pacing the ventricular epicardial surface and inversely estimating the locations of pacing electrodes from the recorded body surface potentials. Two pacing electrode arrays were sutured on the right and left ventricular epicardial surfaces in swine. The hearts were paced by the electrodes sequentially at multiple rates (120–220 bpm), and body surface ECG signals from 64 leads were recorded for the SEMD estimation. We evaluated the combined error of the estimated interelectrode distance and SEMD direction at each time instant during the cardiac cycle, and found the error was minimum when the normalized root mean square (RMSn) value of body surface ECG signals reached 15% of its maximum value. The beat-to-beat variation of the SEMD locations was significantly reduced (p<0.001) when estimated at 15% RMSn compared to the earliest activation time (EAT). In addition, the 5%–95% interval of the estimated interelectrode distance error decreased exponentially as the number of beats used to estimate a median beat, increased. When the number of beats was 4 or larger, the 5%–95% interval was smaller than 3.5 mm (the diameter of a commonly used catheter). In conclusion, the optimal time for the SEMD estimation is at 15% of RMSn, and at that time instant a median beat estimated from 4 beats is associated with a beat-by-beat variability of the SEMD location that is appropriate for catheter ablation procedures.