Adenosine to Assess Complete Conduction Block During Catheter Ablation of Paroxysmal Atrial Fibrillation
Condition: Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Interventional
Phase: Phase 2

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.
    

Intervention name(s): Adenosine; Isoproterenol
Intervention type(s): Drug; Drug
Intervention description(s): 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.; 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.
Other intervention name(s): Isuprel
Intervention MeSH terms: Adenosine; Isoproterenol
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: atrial fibrillation; ablation; adenosine