Feasibility and validation of registration of three-dimensional left atrial models derived from computed tomography with a noncontact cardiac mapping system

Sra, Jasbir; Krum, David; Hare, John; Okerlund, Darin; Thompson, Helen; Vass, Melissa; Schweitzer, Jeff; Olson, Eric; Foley, W. Dennis; Akhtar, Masood

doi:10.1016/j.hrthm.2004.10.035

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Volume 2, Issue 1 , Pages 55-63, January 2005

Feasibility and validation of registration of three-dimensional left atrial models derived from computed tomography with a noncontact cardiac mapping system

Jasbir Sra, MD
- Electrophysiology Laboratories of Aurora Sinai and St. Luke’s Medical Centers, University of Wisconsin Medical School-Milwaukee Clinical Campus, Milwaukee, Wisconsin
- Address reprint requests and correspondence: Dr. Jasbir Sra, 2801 W. KK River Parkway, #777, Milwaukee, Wisconsin 53215.
David Krum, MS
- Electrophysiology Laboratories of Aurora Sinai and St. Luke’s Medical Centers, University of Wisconsin Medical School-Milwaukee Clinical Campus, Milwaukee, Wisconsin
John Hare, BS
- Electrophysiology Laboratories of Aurora Sinai and St. Luke’s Medical Centers, University of Wisconsin Medical School-Milwaukee Clinical Campus, Milwaukee, Wisconsin
Darin Okerlund, MS
- GE Healthcare, Waukesha, Wisconsin
Helen Thompson, BS
- GE Healthcare, Waukesha, Wisconsin
Melissa Vass, BS
- GE Healthcare, Waukesha, Wisconsin
Jeff Schweitzer, MS
- Endocardial Solutions, Inc., St. Paul, Minnesota
Eric Olson, MS
- Endocardial Solutions, Inc., St. Paul, Minnesota
W. Dennis Foley, MD
- Medical College of Wisconsin, Milwaukee, Wisconsin.
Masood Akhtar, MD
- Electrophysiology Laboratories of Aurora Sinai and St. Luke’s Medical Centers, University of Wisconsin Medical School-Milwaukee Clinical Campus, Milwaukee, Wisconsin

Received 16 August 2004; accepted 20 October 2004.

Objectives

The purpose of this study was to determine the feasibility and assess the validity of registering three-dimensional (3D) models from computed tomographic (CT) images using a cardiac mapping system.

Background

Registration of 3D anatomic models with an interventional system could help identify and navigate mapping and ablation catheters over a complex structure such as the left atrium (LA).

Methods

ECG-gated, contrast-enhanced cardiac CT imaging was performed in 14 patients with atrial fibrillation. Segmentation was used to create 3D models of the LA. The 3D models were registered with the mapping system using a series of fiducial points. Registration was accomplished retrospectively in the first 10 patients, and catheter navigation was visualized from recorded data. In the final four patients, registration was accomplished in real time during electrophysiologic study. The mapping catheter position, as it was navigated inside the LA, was applied to the registered model in real time. For the validation study, temporary pacing leads were implanted in the LA of 10 dogs. Following this, CT scanning, segmentation, LA model importation, and registration was described previously. After registration, a mapping catheter was positioned at the site of each buried lead according to the registered model with no fluoroscopic guidance. A radiofrequency lesion was created at this location, and the dog was sacrificed, the heart removed and stained, and the distance between the buried lead and the lesion measured.

Results

During the feasibility study, the location of the catheter in the registered model correlated with fluoroscopy, angiography, and intracardiac electrograms. LA endocardial potentials during sinus rhythm and any premature atrial contractions also were successfully delineated over the registered models. In the validation study, the mean target registration error was 2.0 ± 3.6 mm.