Is adenosine useful for the identification of atrial fibrillation triggers?

Abstract

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. K E Y W O R D S adenosine, atrial fibrillation, isoproterenol, pulmonary vein, triggers 1 | INTRODUCTION Elimination of initiating triggers has become the cornerstone of atrial fibrillation (AF) treatment. Most of these triggers reside in the pulmonary veins (PVs) 1 ; however, non-PV triggers are an important source of recurrence after PV isolation (PVI). Triggers can be identified during the electrophysiology study if spontaneously occurring or can be induced by a drug challenge. Owing to the spurious nature of spontaneous triggers and the laboriousness of AF provocation, empirical isolation of all PVs has become the standard in AF ablation, despite the fact that selective isolation of only the triggering PV can achieve similar success in selected patients. 2 Even if total PV isolation is pursued as a first step, identification of non-PV triggers gains importance when AF occurs despite isolated PVs. 3,4The role of high dose isoproterenol (Iso) infusion to elicit AF triggers is well established. 5,6 Besides Iso, adenosine (Ado) or adenosine triphosphate (ATP) is increasingly used for the induction of AF, despite the lack of systematic studies on the sensitivity and

Efficacy of isoproterenol in the evaluation of dormant conduction and arrhythmogenic foci identification in atrial fibrillation ablation

“…It is reported that adenosine induces AF triggers especially from RA and SVC, but the clinical significance of these foci is questionable [24,25]. On the other hand, ISPinduced AF is more likely initiated from the PVs as compared to that after the administration of adenosine [24]. We also found that all adenosine-induced AF was from RA and SVC.…”

“…Some reports have confirmed the effects of adenosine and ISP on the search for arrhythmogenic foci. It is reported that adenosine induces AF triggers especially from RA and SVC, but the clinical significance of these foci is questionable [ 24 , 25 ]. On the other hand, ISP-induced AF is more likely initiated from the PVs as compared to that after the administration of adenosine [ 24 ].…”

Clinical Significance of Adenosine-Induced Atrial Fibrillation after Complete Pulmonary Vein Isolation

“…Another study showed that when isoproterenol and adenosine were administered to the same patients, isoproterenol mainly induced a PV trigger, whereas adenosine-induced a non-PV trigger, especially in RA. However, the trigger site induced by isoproterenol was correlated with recurrence, whereas the non-PV trigger induced by adenosine did not show a clear correlation with recurrence [ 18 ]. In addition, isoproterenol is more useful than adenosine when non-PV triggers are induced with isoproterenol and adenosine [ 19 ].…”

Understanding the transition from paroxysmal to persistent atrial fibrillation from micro-anatomical re-entry in a simple model

“…In general, patients are much more likely to be free of AF after ablative treatment if AF is paroxysmal. The success rate is around 60% for paroxysmal AF while it is 40% for persistent AF after a three year follow-up [21]. Recurrence rates are also significantly higher for persistent AF after an initially successful treatment.…”