This article appears in the following Europace issue: Spotlight Issue: Cardiac Imaging in EP and CRT [View the issue table of contents]
IMAGING IN CATHETER ABLATION FOR AF
New generation of electro-anatomic mapping: full intracardiac ultrasound image integration
Cardiac Translational Electrophysiology Laboratory, Saint Marys Hospital Complex, Mayo Clinic and Foundation, 2-416 Alfred Building, Rochester, MN 55902, USA
Surrogate electro-anatomic-derived geometries are used as the three-dimensional (3D) basis for mapping of cardiac arrhythmias. While merged computed tomography (CT) imaging may provide stellar pulmonary vein (PV) and left atrial (LA) anatomy, the applied scans must be obtained prior to ablation, and may not reflect physiologic conditions at the time of intervention. Patient-specific, ultrasound-derived 3D imaging has been developed as an alternative basis for new generation electro-anatomic mapping. An electro-anatomic sensor positioned at the tip of the phased-array intracardiac ultrasound catheter, provides the means to specify both location and orientation of each image as the ‘context’ for creating the 3D volumes for co-registration with electro-anatomic mapping. Specific anatomic details such as the pulmonary veins, membranous fossa, papillary muscles, or valve structures derived from real-time imaging can also be integrated into each segmented volume. This presentation reviews the basis and methods for this novel multi-modality image fusion for the creation of robust, nearly real-time anatomic images for guiding electro-anatomic mapping and ablation without requiring pre-acquired CT image sets, with accompanying limitations.
Key Words: Intracardiac ultrasound, Multi-slice computed tomography, Atrial fibrillation, Cardiac anatomy, Electro-anatomic mapping
* Corresponding author. Tel: +1 507 255 6263; fax: +1 507 255 3292. E-mail address: packer.douglas{at}mayo.edu