Pulmonary vein potentials are rapid high frequency deflections of short duration. It follows far field atrial electrogram during left atrial pacing and precedes far field electrogram during pulmonary vein pacing. Far field electrogram is the electrogram of signals originating from a chamber beyond the one in which the mapping electrode is situated. For example ventricular electrogram picked up by an atrial electrode is a far field ectrogram and so is an atrial electrogram picked up by a ventricular electrode.
Prof. Dr. Johnson Francis MD, DM, FACC, FRCP Edin, FRCP London