High Success Rate with Cryomapping and Cryoablation of Atrioventricular Nodal Reentrytachycardia

INTRODUCTION: Cryoablation is a new alternative to radiofrequency (RF) ablation for treatment of atrioventricular nodal reentry tachycardias (AVNRT). Mapping with reversible effect on the arrhythmia substrate or the AV node can be done before irreversible ablation is performed. This study evaluates an approach with systematic cryomapping, ablating only in areas with prompt effect on the arrhythmia substrate and evaluates whether the success rates and procedure times are similar to RF ablation. METHODS AND RESULTS: Seventy-five consecutive patients with typical slow-fast AVNRT were studied. Cryomapping at -30 degrees C was performed before ablation with a goal temperature of -70 degrees C for 240 seconds. The ablation procedure was successful in 74 of the 75 patients, giving an acute success rate of 99%. During a mean follow-up of 338 days, 70 of the 74 primarily successfully ablated patients were free from the treated arrhythmia, giving a recurrence rate of 5% and a total success rate of 93%. Total procedure time including a 30-minute test after successful ablation was 126+/-55 minutes. Fluoroscopy time was 18.5+/-14.9 minutes. CONCLUSION: Cryoablation of AVNRT appears to be as effective as RF ablation both acute and in long term with minimal risks for unwanted injuries on the conduction system. The procedure can be done with reasonable procedure and fluoroscopy times.