Early dose of Adenosine, postRadiofrequency abLation of accessory pathwaY in determining acute procedural Success (EARLY Study)

Introduction Post ablation of the accessory pathway (AP), the patient is observed in the catheterization laboratory for a variable period for resumption of pathway conduction. Aim of the study was to determine whether the administration of intravenous adenosine at 10 minutes after ablation of accessory pathway (AP) would have the same diagnostic accuracy as waiting for 30 minutes in predicting the resumption of AP conduction. Methods: This was a prospective interventional study conducted in two centers. Post ablation of the AP, intravenous adenosine was administered at 10 minutes to look for dormant pathway conduction. The response was recorded as positive (presence of pathway conduction), negative (absence), or indeterminate (not able to demonstrate AV and VA block and inability to ascertain AP conduction). Results: The study included 110 procedures performed in 109 patients. Adenosine administration at 10 minutes showed positive result in 3 cases (2.7%), negative result in 99 cases (90%) and indeterminate result in 8 cases (7.3%). Reconnection of accessory pathway at 30 minutes post ablation was seen in 8 cases (7.3%). Of these 8 cases, 10minutes adenosine administration showed positive test in 3 patients and negative test in 5 patients. Adenosine test at 10 minutes has a sensitivity, specificity, positive predictive value, and negative predictive value of 37.5%, 100%, 100% and 94.9% in identifying the recurrence of accessory pathway conduction at 30 minutes, respectively. Conclusion: Absence of pathway conduction on administration of adenosine 10 minutes post ablation does not help predict the absence of resumption of conduction thereafter.