Comparison between local and systemic injection of adenosine for detecting dormant conduction after PV isolation

Adenosine administration after pulmonary vein (PV) isolation is effective for identifying dormant conduction (DC). We aimed to compare the efficacy and safety of local injection of adenosine into the PV with systemic intravenous injection.

After complete PV isolation was performed, adenosine was injected directly into the PV (local method, 6-18 mg) and the femoral vein (systemic method, 12-30 mg) sequentially. We compared the incidence of DC and the hemodynamic effect of adenosine between the methods.

We analyzed 150 PVs in 40 patients who underwent atrial fibrillation ablation. A total of 16 DCs were seen in 14 patients with either the local or systemic method. Among them, two DCs were detected only by the local method (detection rate: local 10.7% vs systemic 9.3%). The effective doses of adenosine required to induce atrioventricular (AV) block or detect DC were 7.7 ± 3.1 mg (local) and 13.1 ± 3.4 mg (systemic), respectively (P < 0.001). The time interval between adenosine injection and AV block was shorter with the local than systemic method (5.8 seconds vs 11.7 seconds, P < 0.001). Six DCs (four with local and two with systemic method) were detected without manifested AV block. Additionally, there were fewer decrements in blood pressure with the local than systemic method.

Local adenosine injection via the PV was comparable to systemic administration for detecting DC after PV isolation. Furthermore, the local method required a smaller dose of adenosine, took less time to induce AV block, and resulted in less systemic hemodynamic compromise than did the systemic method.