Abstract 3367: Prospective Testing of Isoproterenol and Adenosine After Pulmonary Vein Isolation: Acute Results
Background: Pulmonary vein isolation (PVI) offers an estimated cure rate from atrial fibrillation (AF) of 60 to 80% after the first procedure. While some data suggest that lack of inducibility of AF by electrical stimulation after atrial fibrillation ablation may predict improved outcomes, chemical induction of AF during PVI has not been well-studied. In an on-going prospective study, we seek to determine if chemical induction of AF after PVI with subsequent ablation of elicited triggers improves overall success. Herein, we report acute results of attempted re-induction of AF using adenosine and isoproterenol in patients undergoing PVI.
Methods: Fourty-three consecutive patients with symptomatic AF presented for PVI. Following initial isolation and while catheters were still in place in the left atrium, 18 to 24 mg of IV adenosine was administered as a single bolus. Subsequently, infusion of isoproterenol was administered at up to 20 mcg/min. After administration of each drug, patients were observed for induction of AF or other atrial arrhythmias, focal firing including frequent monomorphic PAC’s or focal atrial tachycardias or evidence of recovery of conduction from the pulmonary veins.
Results: Adenosine administration induced atrial fibrillation in 3 of 43 patients. Notably, no arrhythmias or focal firing were seen with isoproterenol in these three patients. Adenosine did not uncover recovery of conduction from the pulmonary veins in any patient or induce focal firing. Isoproterenol administration induced atrial fibrillation in 3 patients. Focal firing was induced in 18 patients. Recovery of conduction into pulmonary veins was observed after isoproterenol in 6 of 43 patients resulting in application of additional lesions to achieve re-isolation in each case.
Conclusions: Our initial data suggests atrial fibrillation may be chemically re-induced with adenosine and isoproterenol administration in a minority of patients undergoing PVI. Focal firing may also be induced with isoproterenol. Isoproterenol but not adenosine uncovered recovery of conduction into the pulmonary veins in several patients. The mechanism by which arrhythmias and AF initiate may differ with adenosine versus isoproterenol.