Abstract 2881: High-Dose Isoproterenol Reveals Arrhythmogenic Foci Originating From Non-Pulmonary Vein in Patients with Atrial Fibrillation
Backgrounds; Arrhythmigenic foci from non-pulmononay vein (non-PV) also plays an important role for the initiation of atrial fibrillation (AF). The aim was to investigate whether high-dose isoproterenol improves the detection of non-PV foci.
Method; Study population consisted of consecutive 214 patients with AF undergoing catheter ablation (CA) (mean age; 61, Male; 120). We determined arrhythmigenic foci during baseline and after isoproterenol infusion (up to 20 mcg/min) in non-sedation state. We used multipolar catheters, which were simultaneously located in left superior PV, left inferior PV, right superior PV, coronary sinus, superior vena cava, and crista terminalis. If AF persisted spontaneously or was easily induced, we observed spontaneous re-initiation after cardioversion (up to 3 times).
Results; 500 arrhythmigenic foci were detected. 263 AFC (53%) were confirmed as AF initiator in 174 patients (82%), and 237 AFC (47%) were reproductive premature beats with interval < 350 ms or frequent repetitive firing in 150 patients (70%). Non-PV foci were detected in 107 patients (49%). Locations of 142 Non-PV foci include left atrial posterior wall (31, 14%), superior vena cava (41, 21%), crista terminalis (16, 7.4%), mitral ishmus area (15, 6.9%), left atrial roor (12, 4.6%), atrial septum (7, 3.7%), Coronary sinus (16, 7.4%) and others (4, 1.5%). After high-dose isoproterenol (ranged in 2–20 mcg/min), the prevalence of non-PV foci was significantly higher than that of PV foci (32% vs. 55%, p<0.05). 98 patients (45.6%) had both PV foci and non-PV foci, and 8 patients (4%) had only non-PV foci. Coupling interval of PV foci was shorter than that of non-PV foci (196 vs. 255ms, p<0.01), and PV foci were more likely to be associated with AF than non-PV foci (61% vs. 28%, p<0.01). Number of arrhythmogenic foci, however was higher in patients with non-PV foci than in those PV foci alone (3.1 vs. 1.6, p<0.01), and the patients with arrhythmogenic foci ≥ 3 showed the significant higher recurrence ratio after CA than those with foci ≤ 2(w/o medication; 54% vs. 33%, p<0.05, w/i medication; 29% vs. 15%, p<0.05).
Conclusion; 1) High-dose isoproterenol improves the detection of non-PV foci in patients with AF, and non-PV foci has important clinical implications.