Separating atrial near fields and atrial far fields in simulated intra-Atrial electrograms

The detailed characterization of complex forms of atrial flutter relies on the correct interpretation of intra-atrial electrograms. For this, the near fieldcomponents, which represent the local electrical activity, are decisive. However, far field components arising from distant electrical sources in the atria can obscure the diagnosis.We developed a method to separate and characterize atrial near field and atrial far field components from bipolar intra-atrial electrograms. First, a set of bipolar electrograms was created by simulating different propagation scenarios representing common clinical depolarizationpatterns. Second, near and far fields were detected as active segments usinga non-linear energy operator-based approach. Third, the maximum slope and the spectralpower were extracted as features for all active segments. Active segments were grouped accounting for both the timing and the location of their occurrence. In a last step, the active segments were classified in near and far fields by comparing their feature values to a threshold.All active segments were detected correctly. ... mehr On average, near fields showed 15.1x larger maximum slopes and 40.4x larger spectral powers above 100 Hz than far fields. For 135 active segments detected in 72 bipolar electrograms, 5.2% and 6.7% were misclassified using the maximum slope and the spectral power, respectively. All active segments were classified correctly if only one near field segment was assumed to occur per electrogram.The separation of atrial near andatrial far fields was successfully developed and applied to in silico electrograms.Theseinvestigations providea promising basis fora future clinical study to ultimatelyfacilitatethe precise clinical diagnosis of atrial flutter.