Comparison of electrogram organization and synchronization indices in atrial fibrillation: A simulation study

In this work, a comparative study of several electrogram (EGM) organization and synchronization indices in atrial fibrillation (AF) has been performed. To do this, a realistic EGM simulator has been designed. In order to see how the indices are affected by noise and local activation time and conduction variability, the signal-to-noise ratio (SNR), the delay between leads and its variability have been modified in a controlled way. With these different signals, several EGM risk indices (based on spectral, cross-covariance, information and wavefront analysis) have been calculated. Results suggest that indices based on spectral and cross-covariance analysis (organization index, spectral coherence and maximum normalized cross-covariance) are more robust than those based on wavefront or cross-information in quantifying the organization, synchronization and delay when SNR is reduced.