Conditions: Atrial Fibrillation
Keywords: atrial fibrillation ablation adenosine
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 131
Healthy volunteers: no

Brief summary:
The purpose of this study is to determine if additional ablation during the first procedure as the result of the ability to medically induce quiet atrial arrhythmias will improve clinical outcome in patients with atrial fibrillation thus decreasing the need for additional ablation procedures.

Detailed description:
Hypothesis:

1. Adenosine reveals incomplete conduction block due to partial tissue injury/stunning during catheter ablation of atrial fibrillation.
2. Identification of incomplete conduction block by adenosine improves clinical outcomes including an increase in efficacy and a decrease in need for repeat procedures after catheter ablation of atrial fibrillation.

Objectives:

1. In patients with paroxysmal Atrial Fibrillation (AF), the prevalence of Pulmonary Vein (PV) reconnection during adenosine infusion after complete PV isolation using conventional techniques will be determined.
2. Patients will be randomized to further ablation to achieve complete isolation during adenosine infusion vs to no further ablation.
3. Primary endpoint of the study will be freedom from any atrial arrhythmias 6 months after a single ablation procedure in the absence of antiarrhythmic drug therapy.
4. Secondary endpoints will include number of repeat ablation procedures because of documented recurrence of symptomatic AF or atrial flutter/tachycardia, outcome after 2 ablation procedures; Proportion of patients with AF or atrial flutter/tachycardia occuring during the first three months post ablation, prevalence of recovery of conduction into PVs during repeat ablation procedures in both groups, procedure duration, and incidence of peri-procedural complications including stroke, PV stenosis, cardiac perforation, atrio-esophageal fistulae, and death.

Arms:
arm 1: Patients in this group will receive 12-24mg of adenosine for each PV in order to assess dormant PV conduction. arm 2: This group will not receive adenosine during the procedure.

Interventions: intervention 1: Adenosine intervention 2: Isoproterenol
Intervention descriptions: intervention 1: Subject will receive 6-24 mg of intravenous adenosine given rapidly for each PV in order to assess dormant PV conduction.

Subjects in this group will also receive isoproterenol to assess inducibility of AF with re-isolation of PVs and targeting non PV sources of AF if necessary.Isoproterenol will be infused through a femoral vein at rates of 5, 10, 15, and 20 μg/min for 2 minutes at each infusion rate. intervention 2: Isoproterenol will be infused through a femoral vein at rates of 5, 10, 15, and 20 μg/min for 2 minutes at each infusion rate. The isoproterenol infusion will be discontinued upon induction of AF, a decrease in systolic blood pressure to\<85 mmHg, complaints of severe chest tightness, electrocardiographic changes suggestive of ischemia, or upon completion of the infusion protocol.

Protocol document: