Intravenous adenosine to predict conduction recurrence in cavotricuspid isthmus early after ablation of typical atrial flutter: myth or reality?

INTRODUCTION: Early recovery of conduction (ER) after cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFl) occurs in approximately 10% of the patients. If not recognized, ER might lead to AFl recurrences. In this study, we hypothesized that intravenous adenosine (iADO) can be used to predict ER in the CTI immediately after RF ablation and distinguish functional block from the complete destruction of the CTI myocardium.

METHODS: We prospectively included 68 consecutive patients (age: 65 ± 14 years; male: 78%) referred in our centers for AFl ablation. Immediately after bidirectional isthmus block validation, a bolus of iADO was given during continuous pacing from the proximal coronary sinus. Patients with functional block revealed under iADO (iADO+) and those without (iADO-) were subsequently observed for a 30-minute waiting period (ER-) or until sustained recovery of the conduction through the CTI (ER+).

RESULTS: Seven patients presented a persistent recovery (ER+, 10.3%, mean time to recovery: 14 ± 9 minutes). None of them presented even a transient resumption of conduction under iADO (iADO+: 0). With univariate analysis, we identified a heavy patient weight (>95 kg) as a predictor of ER (sensitivity: 71%).

CONCLUSIONS: Adenosine does not predict early recovery in the CTI after linear ablation for atrial flutter. We found that a patient weight over 95 kg predicted early recovery of conduction through the CTI with a sensitivity of 71%.