Global distribution of atrial ectopic foci triggering recurrence of atrialtachyarrhythmia after electrical cardioversion of long-standing atrial fibrillation: A bi-atrial basket mapping study

OBJECTIVES The objective of this study was to assess the spatial distributi on of atrial ectopic fod potentially triggering recurrent atrial tachyarrhy thmias after electrical cardioversion of long-standing atrial fibrillation (AF). BACKGROUND It remains unknown whether targeted ablation of atrial ectopic f oci concentrated in the pulmonary veins is feasible in patients with long-s tanding AF as it is in patients with paroxysmal AF. METHODS Two basket electrodes (32 bipoles on each eight splines) were posit ioned in the right and left atrium to identify the earliest endocardial act ivation sites of atrial ectopic foci emerging immediately after external el ectrical cardioversion of long-standing AF, before and after intravenous ad ministration of dl-sotalol (16 patients) and propafenone (16 patients). RESULTS Before the use of antiarrhythmics, 91 distinct atrial ectopic foci were recognized after cardioversion. In 69 of the 91 foci, the earliest sit es of presystolic atrial activation could be identified. Left atrial poster ior (16 foci), left atrial anterior (11 loci) and right atrial posterior re gions (13 foci) appeared to be prevalent. However, atrial ectopies from the remaining atrial regions (29 fed) were not uncommon. After adding dl-sotal ol or propafenone, only 64 atrial ectopic foci were recognized after cardio version; 50 of those were identifiable at the earliest activation sites. Th e scattered pattern of spatial distribution of the atrial ectopic foci was Virtually unchanged. CONCLUSIONS Atrial ectopic foci potentially triggering the recurrence of at rial tachyarrhythmias after successful electrical cardioversion of long-sta nding AF were scattered in spatial distribution at-id multiple in productio n, possibly rendering difficult the targeted ablation approach. (J Arm Coil Cardiol 2001;37:904-10) (C) 2001 by the American College of Cardiology.