Coronel R, Wilms-Schopman F J, de Groot J R, Janse M J, van Capelle F J, de Bakker J M
Experimental and Molecular Cardiology Group, Cardiovascular Research Institute Amsterdam, and the Interuniversity Cardiology Institute, The Netherlands.
J Cardiovasc Electrophysiol. 2000 Oct;11(10):1119-28. doi: 10.1111/j.1540-8167.2000.tb01758.x.
During ventricular fibrillation (VF), interpretation of a local electrogram and determination of the local activation moment are hampered by remote activity or intervening repolarization waves. Successful defibrillation depends on critical timing of the shock relative to local activation. We tested the applicability of Laplacian electrograms for detection of the moment of local activation during VF.
From isolated perfused porcine intact hearts, 247 local unipolar electrograms were recorded simultaneously (13 x 19 matrix, interelectrode distance 0.3 mm) from the left ventricular wall during sinus rhythm, following pacing or during VF. Activation maps were constructed based on local unipolar electrograms, and Laplacian electrograms were calculated from local electrograms and its eight neighbors. The Laplacian electrogram displayed a sharp R/S complex with local activation indicated by the moment of zero crossing without interference from remote activity or repolarization waves. Its amplitude increased with decreasing interelectrode distance. Following epicardial stimulation, Laplacian amplitude was significantly larger than during a breakthrough pattern. During VF, identical unipolar electrograms corresponded to Laplacian complexes with different morphology. Collision of wavefronts was associated with entirely positive Laplacian waveforms; "focal" appearance of activity was associated with an entirely negative waveform. Activation block in the activation maps was correlated with the appearance of sustained episodes of negativity or positivity in the Laplacian electrogram (depending on the location of the recording site relative to the line of block).
Laplacian electrograms allow detection of the moment of local activation without interference from remote activity or repolarization, especially during complex arrhythmias. The technique applied to automatic sensing devices, such as the internal defibrillator, may optimize defibrillation success.
在心室颤动（VF）期间，局部心电图的解读以及局部激动时刻的确定会受到远处活动或介入复极波的干扰。成功除颤取决于电击相对于局部激动的关键时机。我们测试了拉普拉斯心电图在检测VF期间局部激动时刻的适用性。
从离体灌注的完整猪心脏中，在窦性心律、起搏后或VF期间，同时从左心室壁记录247个局部单极心电图（13×19矩阵，电极间距0.3毫米）。基于局部单极心电图构建激动图，并从局部心电图及其八个相邻心电图计算拉普拉斯心电图。拉普拉斯心电图显示出尖锐的R/S复合波，零交叉时刻指示局部激动，不受远处活动或复极波的干扰。其振幅随着电极间距的减小而增加。心外膜刺激后，拉普拉斯振幅明显大于突破模式期间。在VF期间，相同的单极心电图对应不同形态的拉普拉斯复合波。波前碰撞与完全正向的拉普拉斯波形相关；活动的“局灶性”外观与完全负向的波形相关。激动图中的激动阻滞与拉普拉斯心电图中持续的负性或正性发作的出现相关（取决于记录部位相对于阻滞线的位置）。
拉普拉斯心电图能够检测局部激动时刻，不受远处活动或复极的干扰，尤其是在复杂心律失常期间。应用于自动传感装置（如体内除颤器）的该技术可能会优化除颤成功率。
