1. Date of download: 6/22/2016 Copyright © The American College of Cardiology. All rights reserved. From: Global distribution of atrial ectopic foci triggering recurrence of atrial tachyarrhythmia after electrical cardioversion of long-standing atrial fibrillation: a bi-atrial basket mapping study J Am Coll Cardiol. 2001;37(3):904-910. doi:10.1016/S0735-1097(00)01192-X The positioning of two basket electrodes in the right and left atrium in patients with chronic atrial fibrillation. Each basket electrode has eight splines and 32 bipoles (four bipoles on each spline). The basket electrode in the left atrium was deployed via trans-septal technique. The radiodense markers (A, B, C) indicate the spline “A,” “B” (Constellation basket, right panel) and “C” (Mercator basket, left panel). Figure Legend:

2. Date of download: 6/22/2016 Copyright © The American College of Cardiology. All rights reserved. From: Global distribution of atrial ectopic foci triggering recurrence of atrial tachyarrhythmia after electrical cardioversion of long-standing atrial fibrillation: a bi-atrial basket mapping study J Am Coll Cardiol. 2001;37(3):904-910. doi:10.1016/S0735-1097(00)01192-X Early reinitiation of two episodes of atrial fibrillation (AF) in a patient after successful cardioversion of chronic AF. The recurrent episodes of AF were initiated by atrial ectopic triggers from either the right atrium (Panel A) or the left atrium (Panel B). The intra- cardiac tracings in panel A and panel B were obtained from the basket electrodes in the right atrium and the left atrium, respectively. The 32 intra-atrial local electrogram channels represent the 32 bipolar recording sites from the eight splines of the basket electrode (from spline “A” to spline “H”) and the four sites on each spline (from site 1 to site 4). The earliest activation sites for the right atrial trigger (Panel A) were identified simultaneously at F 3 and F 4 corresponding to the right atrial septal-inferior region (i.e., the coronary sinus ostium region) and were 36 ms preceding the onset of the P-wave on the surface electrocardiogram, while the left atrial trigger was found earliest at the E 4 corresponding to the left atrial posterior-inferior region (i.e., the left lower pulmonary vein orifice region) and was 35 ms preceding the P wave. Arrowheads indicate the earliest activation sites of the atrial ectopic triggers for the recurrent AF. Figure Legend:

3. Date of download: 6/22/2016 Copyright © The American College of Cardiology. All rights reserved. From: Global distribution of atrial ectopic foci triggering recurrence of atrial tachyarrhythmia after electrical cardioversion of long-standing atrial fibrillation: a bi-atrial basket mapping study J Am Coll Cardiol. 2001;37(3):904-910. doi:10.1016/S0735-1097(00)01192-X Early reinitiation of nonsustained atrial tachycardia by an atrial ectopic beat after successful electrical cardioversion with intravenous propafenone in a patient with chronic atrial fibrillation. The tracings shown here represent the basket electrode in the right atrium. The left panel shows a sinus beat and an atrial ectopic beat, which had the earliest breakthrough at D3 and D4 sites (arrowheads). The right panel shows the reinitiation of nonsustained atrial tachycardia (cycle length 270 ms) by a similar atrial ectopic beat. The earliest activation site of the triggering atrial ectopic beat was simultaneously found at D3, D4 and E3 sites (arrowheads), which was 35 ms before the onset of the P-wave on the surface electrocardiogram and was located at the anterior- inferior region of the right atrium (i.e., the lower crista terminalis region). Figure Legend: