A left atrial segmentation procedure or wide area catheter ablation procedure (aka "WACA") is at times needed to achieve cure of chronic atrial fibrillation.  This procedure involves multiple linear and circular ablation lesions delivered into the left atrial with the help of 3D magnetic navigation.

A Left atrial segmentation procedure or WACA; The red dots are ablation lesions delivered with using a 3D mapping computer. The colored tubes are the pulmonary veins.  The pink dots are the patients esophagus which we like to monitor during the procedure.  This picture shows the back or posterior view of the left atria, the ablation lesions however extend around to include the front side of the heart.

As you can see from the above ablation map of one of our patients, a series of ablation lesions are delivered into the left atrial segmenting the atrial into defined regions.  This procedure is very similar to an open "Maze" procedure in the way the ablation lesions are delivered.  In general, this procedure is performed in patients who have chronic (also called persistent or permanent) atrial fibrillation.

A graph from a recently published study showing 87% of patients with chronic atrial fibrillation having termination of atrial fibrillation into normal sinus rhythm during an LA segmentation or WACA procedure. The 4 steps to 87% termination refers to the number of structures in the left atria ablated not to the number of ablation procedures; all 87% of patients in this study terminated their atrial fibrillation during a single ablation procedure. ref: Jais, et al, Journal of Cardiac ELectrophysiology, Nov 2005