Comparison of atrial wave extraction methods from invasive recordings in atrial fibrillation

A key issue to understand the pathophysiological mechanisms of atrial fibrillation (AF) is the analysis and interpretation of atrial electrograms (AEG). To properly study these signals, ventricular artifacts have to be removed. This work presents a new application of independent component analysis (ICA) to reduce ventricular artifacts from AEG recordings making use of only one reference lead. Therefore the technique is suitable when multi-lead recordings are unavailable as in atrial implantable cardioverter-defibrillators. The methodology has been compared with traditional techniques on a database of 20 patients. Performance was evaluated through atrial waveform similarity and ventricular activity reduction as a function of atrial rhythm regularity on a beat-by-beat basis. When the atrial activity is quite regular, results show that ICA preserves the atrial waveform better than the other methods whereas maintaining ventricular reduction.