Diagnosis and ablation of focal right atrial tachycardia using a new nigh-resolution, non-contact mapping system

Conventional electrophysiologic catheter techniques are used to identify the mechanisms and origin of cardiac tachyarrhythmias in symptomatic patients.(1-6) The identified arrhythmogenic substrate can be targeted and ablated using radiofrequency current with a generally high success rate.(1,7) Patients in whom the clinical arrhythtnia is atypical, unstable, not readily reproducible, or poorly tolerated often require extensive and multicatheter electrophysiologic evaluation including various pacing maneuvers to confirm the tachycardia mechanism and origin.(8,9) Ablation procedures in these patients are time consuming and sometimes unsuccessful and may be related in part to conventional catheter techniques allowing only recordings from a limited amount of sites simultaneously. Therefore, to overcome the limitations in mapping methods, new mapping techniques and catheters have recently been introduced.(10-12) One of these is a high-resolution non-contact mapping system designed to create endocardial activation maps of the surrounding chamber by recording from >3,300 sites simultaneously and to guide ablation catheters to potential ablation sites. Clinical experience of this new technology in humans is still very limited.(11,13,14) Therefore, we investigated the clinical performance, safety, and efficacy of the system as a diagnostic and therapeutic tool in patients with focal right atrial tachycardias. It was the purpose of the study to rapidly determine the tachycardia origin and to ablate the arrhythmia using the nonfluoroscopic-guiding capabilities of the non-contact mapping system.