High-Dose Dobutamine for Inducibility of Atrial Arrhythmias During Atrial Fibrillation Ablation.

Objectives: This study sought to compare the effect of high-dose dobutamine (DBT) with that of high-dose isoproterenol (IPN) in eliciting triggers during atrial fibrillation (AF) ablation.

Background: High-dose IPN is commonly used to elicit triggers during AF ablation. However, it is not available worldwide and, in the United States, its cost per dose has significantly increased. DBT is a similarly nonselective β-agonist and, as such, is a potential alternative.

Methods: This was a prospective, randomized 2×2 crossover study of patients undergoing AF ablation. Patients were assigned to receive IPN (20 to 30 μg/min for 10 min) followed by DBT (40 to 50 μg/kg/min for 10 min) or vice versa in a 1:1 fashion. The type, number, and location of triggers as well as heart rate, blood pressure, and side effects were noted.

Results: Fifty patients were included in the study. Both drugs caused a significant increase in heart rate, with a consistently lower peak for DBT. Blood pressure significantly increased with DBT, while there was a significant reduction with IPN, despite phenylephrine support. Atrial arrhythmias induced during DBT were comparable to that induced during IPN. In patients with IPN-inducible outflow tract premature ventricular contractions, a similar effect was noted with DBT. No major complications occurred during either drug challenge.

Conclusions: High-dose DBT is safe and comparable to high-dose IPN in respect of eliciting AF triggers, with the advantage to maintain systemic pressure without the need of additional vasopressor support. This study supports the use of high-dose DBT in electrophysiology laboratories in which IPN is not readily available and for those patients in whom hypotension is a concern.