Separative Surface Potential Activation Beamformer for Localizing Reentrant Excitation of Atrial Fibrillation

We introduce a novel beamforming method named separative surface potential activity beamformer (sSPAB) for MCG source localization. By using this method, we can visualize an activity map of the action potential (AMAP) on the myocardial surface corresponding to a time-specific waveform of measured magnetic fields with an MCG. The method is especially feasible for localization of a rhythmic activity and we used this method for studies of atrial fibrillation (AF). Included in the study were four patients with chronic AF. The obtained f-waves show periodic oscillatory behaviors. By using the sSPAB, we separate the f-wave from the other activations and localize the position of a reentry circuit corresponding to the f-wave. By separating the f-wave time-by-time and visualizing the AMAP for each time-separated waveform, we were able to infer the propagation trace of the AF. After the MCG map-guided minimal AF surgery, the patients´ AF rhythm converted Sinus successfully. With follow-ups, their sinus rhythm is well preserved.