Rieta José Joaquín, Hornero Fernando
Biomedical Synergy, Valencia University of Technology, Campus de Gandia, 46730, Gandia, Spain.
Physiol Meas. 2007 Aug;28(8):925-36. doi: 10.1088/0967-3334/28/8/014. Epub 2007 Jul 19.
Atrial fibrillation is a very common cardiovascular disease in clinical practice. One relevant issue to understand its pathophysiological mechanisms is the analysis and interpretation of atrial electrograms (AEG). To study these signals properly, ventricular activity has to be removed from the AEG. In this work, a new application of independent component analysis (ICA) to the AEG is presented, where ventricular activity is removed from atrial epicardial recordings making use of only one reference lead. Therefore the technique is suitable when multi-lead recordings are unavailable as in atrial implantable cardioverter defibrilators. In addition to the proposed new methodology this work also presents the first comparative study, making use of unipolar epicardial AEGs, among the ICA-based technique, template matching and subtraction (TMS), and adaptive ventricular cancellation (AVC) on a database of 20 patients. A performance comparative analysis was carried out by evaluating epicardial atrial waveform similarity (S) and ventricular depolarization reduction (VDR) as a function of atrial rhythm regularity on a beat-by-beat basis. Results indicate that, when the epicardial atrial rhythm is quite organized, ICA is able to preserve the atrial waveform very precisely and better than the other methods (median S = 99.64% +/- 0.31% in contrast to 95.18% +/- 2.71% for TMS and 94.76% +/- 4.12% for AVC). Moreover, ventricular reduction is the best for ICA (median VDR = 6.32 +/- 4.41 dB in contrast to 4.98 +/- 4.48 dB for TMS and 4.12 +/- 2.72 dB for AVC). On the other hand, when the atrial activity is disorganized, TMS notably improves performance (S = 97.72% +/- 1.87%), but ICA still is the best in waveform preservation (S = 98.22% +/- 1.53%) whereas AVC remains similar (S = 93.74% +/- 4.38%). In conclusion, ICA can be considered as notably the best approach to reduce ventricular activity from unipolar atrial electrograms in organized atrial arrhythmias. On the other hand, both TMS and ICA give quite similar results when the atrial arrhythmia is disorganized.
心房颤动是临床实践中一种非常常见的心血管疾病。理解其病理生理机制的一个相关问题是心房电图（AEG）的分析和解读。为了正确研究这些信号，必须从AEG中去除心室活动。在这项工作中，提出了独立成分分析（ICA）在AEG中的一种新应用，即仅利用一个参考导联从心房心外膜记录中去除心室活动。因此，当如心房植入式心律转复除颤器那样无法获得多导联记录时，该技术是适用的。除了所提出的新方法外，这项工作还利用单极心外膜AEG，在基于ICA的技术、模板匹配与减法（TMS）以及自适应心室消除（AVC）之间，对20例患者的数据库进行了首次比较研究。通过逐搏评估心外膜心房波形相似度（S）和心室去极化减少（VDR）作为心房节律规整性的函数，进行了性能比较分析。结果表明，当心外膜心房节律相当规整时，ICA能够非常精确地保留心房波形，且优于其他方法（中位S = 99.64%±0.31%，而TMS为95.18%±2.71%，AVC为94.76%±4.12%）。此外，ICA的心室减少效果最佳（中位VDR = 6.32±4.41 dB，而TMS为4.98±4.48 dB，AVC为4.12±2.72 dB）。另一方面，当心房活动不规整时，TMS显著提高了性能（S = 97.72%±1.87%），但ICA在波形保留方面仍然最佳（S = 98.22%±1.53%），而AVC保持相似（S = 93.74%±4.38%）。总之，在规整性心房心律失常中，ICA可被视为从单极心房电图中减少心室活动的最佳方法。另一方面，当心房心律失常不规整时，TMS和ICA给出的结果相当相似。
