Is this vein isolated or not? How a new advanced algorithm helps find unconventional far-field sources

Multielectrode mapping catheters placed within pulmonary veins (PVs) usually detect an initial far-field electrogram (EGM) and then a sharp near-field EGM, which represents the local PV activity. The PV myocardial origin of the second potential is indicated by near-field characteristics of higher voltage and slope, proximal to distal activation within the vein. However, as there is significant overlap of amplitudes and slopes, these parameters...