Adenosine triphosphate (ATP) frequently triggers atrial fibrillation (AF), but the clinical significance of this phenomenon is unknown. The purpose of this study was to reveal the relevance between spontaneous AF and ATP-induced AF.

In 81 AF patients undergoing pulmonary vein isolation (PVI), we injected 20 mg of ATP before PVI, and recorded triggering sites of the AF induced. We also injected 20 mg of ATP in 44 patients receiving ablation for atrioventricular reciprocating tachycardia (AVRT).

ATP provoked AF in 24 (29.6 %) of the 81 PVI patients and atrial ectopic beats in a further 48 (59.3 %). The trigger site of the AF was in the PV and the right atrium in 22 (91.7 %) and 2 patients, respectively. In 14 of those 24 patients, spontaneous AF arose from the same triggering site as the ATP-induced AF. In the 48 patients with ATP-provoked ectopic beats, spontaneous AF arose from the same site in 13. Conversely, among the 34 patients demonstrating spontaneous AF initiation, AF or ectopic beats were provoked by ATP from the same site in 14 (41.2 %) and 13 patients (38.2 %), respectively. ATP provoked AF in only 2 (4.5 %) of the AVRT patients. In summary, ATP provoked AF or atrial ectopic beats in 88.9 % of PVI patients, 36.1 % of whose triggering sites matched that of the spontaneous AF, while 79.4 % of spontaneous AF trigger sites matched ATP-provoked AF or ectopic beat sites.

ATP-induced AF was strongly associated with clinical AF, and ATP is useful for identifying arrhythmogenic sites.