Epicardial atrial activation assessment from the surface ECG in atrial fibrillation

Atrial fibrillation (AF) is one of the most common complication of cardiothoracic surgery affecting from 30% up to 60% of the patients. In this study 15 patients undergoing cardiac surgery, that developed postoperative atrial fibrillation, were selected to assess if the information available in epicardial recordings can be recovered with the only use of body surface recordings. Surface ECGs were processed by independent component analysis (ICA) to extract a unified surface atrial activity (AA) that takes into account the atrial contribution of each lead. Next, the estimated AA has been compared with epicardial recordings, the spectral cross-correlation being 85.34plusmn11.08% (range 60.57-97.31) and the average spectral coherence 70.10plusmn9.46% (range 54.92-83.95). Therefore, this study has assessed that information provided by the surface ICA-estimated AA is a valid and useful tool to analyze the properties of atrial activation patterns in AF patients, thus allowing to improve the information about atrial arrhythmias in those patients where epicardial recordings are unavailable