Introduction: Both isoproterenol (Iso) and adenosine (Ado) are used to induce atrial fibrillation (AF) in the electrophysiology lab. However, the utility of Ado has not been systematically established.
Objective: The purpose of this study was to compare Ado to Iso for the induction of paroxysmal AF.
Methods: Forty patients (16 women; mean age, 60 ± 12 years) with paroxysmal AF, presenting for ablation were prospectively included of whom 36 (90%) received Ado (18-36 mg) and/or Iso (3-20 µg/min incremental dose) in a randomized order (26 [72%] received both drugs).
Results: AF was induced with Iso in 15 of 32 (47%) and with Ado in 12 of 30 (40%) patients (P = 0.9). Iso-triggered AF started from the left pulmonary veins (PVs) in 11 of 15 (73%), from the right PVs in 3 of 15 (20%), and from the coronary sinus (CS) in 1 of 15 (7%) cases. Ado-induced AF episodes originated from the left PVs in 6 of 12 (50%), from the right atrium (RA) in 4 of 12 (33%), and from the CS in 2 of 12 (17%) cases. Altogether, Iso-induced AF was more likely initiated from the PVs (93%) compared with Ado (50%) ( P = 0.02). Ado-induced non-PV triggers were not predictive of arrhythmia recurrence after PV isolation.
Conclusion: Ado much more frequently induces non-PV triggers, especially from the RA. The clinical significance of these foci, however, is questionable.
Keywords: adenosine; atrial fibrillation; isoproterenol; pulmonary vein; triggers.
© 2018 Wiley Periodicals, Inc.