Induction of Atrial Fibrillation by Isoproterenol and Adenosine: The Importance of Concurrent Administration to Access the AF Inducibility

Abstract

Background: The inducibility of atrial fibrillation (AF) by Isoproterenol (ISP) and adenosine triphosphate (ATP) has not been sufficiently investigated. Methods: This study consisted of consecutive 69 paroxysmal AF patients who underwent the pulmonary vein antrum isolation (PVAI). During sinus rhythm, the AF inducibility by venous injection of either ATP (20–40 mg) or ISP (4–8 µg) or concurrent administration both of ISP and ATP was examined before and after the PVAI. Results: In total, AF was induced from 36 sites in 50.7% (35/69) of patients, triggered by firing from PVs, superior vena cava in 34 and one patient, respectively. AF was more frequently induced by concurrent administration both of ISP and ATP compared to injection of solo-ATP or solo-ISP (43.5% (30/69) vs. 23.2% (16/69) vs. 21.7% (15/69), P=0.007). Of 30 patients with AF induction by concurrent administration both of ATP and ISP, AF was not induced by solo-ATP or solo-ISP only in 14 (46.7%) patients. Following ablation, no AF could be induced by any administration of ISP and ATP. Conclusion: Solo use of ATP or ISP was insufficient to induce AF. Concurrent administration both of ISP and ATP is useful for induction of AF in patients with paroxysmal AF.