A simple method of mapping atrial premature depolarizations triggering atrial fibrillation

Atrial premature depolarizations (APDs) originating from focal sites, particularly the pulmonary veins (PV), may become triggers of atrial fibrillation (AF). Accurate mapping of APDs with conventional methods may be time consuming and expose the patient to unnecessary instrumentation of the left atrium. We hypothesized that the atrial activation sequence recorded using a simple system that includes an esophageal catheter and a custom-made 16-electrode catheter with two sets of floating electrodes eight in the coronary sinus and eight in the high right atrium) could be sufficient to localize the APDs. The study included 29 patients with frequent APDs and AF refractory to antiarrhythmic medications. The APD site of origin was confirmed with single-point sequential mapping techniques using the CARTO system ten patients) or by placement of multielectrode catheters in the right and left PV (19 patients). Of the 29 patients, 20 patients had a single APD focus; 8 patients had two different APD morphologies; and 1 patient had three APD foci. Mapping for ablation of the APD foci showed earliest activation in the left superior PV in 12 patients, right superior PV in 15 patients, right middle PV in 4 patients, right inferior PV in 1 patient, the lingular branch of the left superior PV in 2 patients, left inferior PV in 2 patients, and right atrium along the crista terminalis in 3 patients. The activation sequence and relative timing of the recordings obtained with our catheter configuration was highly predictive of right and left atrial origin and, more importantly, of right and left PV foci.