“…Compared with these patients, ours is unique in 2 ways. In 2 of these patients, automaticity was not spontaneous but was provoked by ablation, with the arrhythmias appearing after ablation not reliably differentiated from the ventricular rhythm arising from a nearby focus, as there was no retrograde conduction and resulting preceding atrial activation, as in our patient. In the other 2 patients the arrhythmias could not be differentiated from atrial foci adjacent to the AP as the AP was overt, rather than concealed as in our patient.…”