Electrical Disconnection of the Superior Vena Cava from the Right Atrium

Catheter Ablation of Paroxysmal Atrial Fibrillation Originating from Non-pulmonary Vein Areas

Pulmonary veins (PVs) are a major source of ectopic beats that initiate AF. PV isolation from the left atrium is an effective therapy for the majority of paroxysmal AF. However, investigators have reported that ectopy originating from non-PV areas can also initiate AF. Patients with recurrent AF after persistent PV isolation highlight the need to identify non-PV ectopy. Furthermore, adding non-PV ablation after multiple AF ablation procedures leads to lower AF recurrence and a higher AF cure rate. These findings suggest that non-PV ectopy is important in both the initiation and recurrence of AF. This article summarises current knowledge about the electrophysiological characteristics of non-PV AF, suitable mapping and ablation strategies, and the safety and efficacy of catheter ablation of AF initiated by ectopic foci originating from non-PV areas.

Initial experience in the use of integrated electroanatomic mapping with three-dimensional MR/CT images to guide catheter ablation of atrial fibrillation

INTRODUCTION

No prior studies have reported the use of integrated electroanatomic mapping with preacquired magnetic resonance/computed tomographic (MR/CT) images to guide catheter ablation of atrial fibrillation (AF) in a series of patients.

METHODS AND RESULTS

Sixteen consecutive patients with drug-refractory AF underwent catheter ablation under the guidance of a three-dimensional (3D) electroanatomic mapping system (Carto, Biosense Webster, Inc., Diamond Bar, CA, USA). Gadolinium-enhanced MR (n = 8) or contrast-enhanced high-resolution CT (n = 8) imaging was performed within 1 day prior to the ablation procedures. Using a novel software package (CartoMerge, Biosense Webster, Inc.), the left atrium (LA) with pulmonary veins (PVs) was segmented and extracted for image registration. The segmented 3D MR/CT LA reconstruction was accurately registered to the real-time mapping space with a combination of landmark registration and surface registration. The registered 3D MR/CT LA reconstruction was successfully used to guide deployment of RF applications encircling the PVs. Upon completion of the circumferential lesions around the PVs, 32% of the PVs were electrically isolated. Guided by a circular mapping catheter, the remaining PVs were disconnected from the LA using a segmental approach. The distance between the surface of the registered 3D MR/CT LA reconstruction and multiple electroanatomic map points was 3.05 +/- 0.41 mm. No complications were observed.

CONCLUSIONS

Three-dimensional MR/CT images can be successfully extracted and registered to anatomically guided clinical AF ablations. The display of detailed and accurate anatomic information during the procedure enables tailored RF ablation to individual PV and LA anatomy.