Cardiac Procedure Eliminates X-Ray Exposure

An innovative X-ray free technique to treat atrial fibrillation (AF) could all but eliminate the risk of radiation exposure for patients and staff.

Researchers at the University of Virginia Health System (UVA; Charlottesville, VA, USA) developed and successfully tested a new technique to perform catheter ablation of AF using an intracardiac echocardiography (ICE) device and electro-anatomic mapping using an ultrasound catheter, without the use of X-ray fluoroscopy for the entire procedure. The procedure involved a decapolar catheter advanced through the left subclavian vein until stable coronary sinus electrograms appeared on all electrodes. Two 9F sheaths were then advanced transfemorally over a guide wire to the right atrium, and a rotational ICE catheter was advanced through a deflectable sheath. A double transseptal puncture was then performed under ICE guidance and facilitated by electrocautery.

The novel technique also uses a computer mapping system, which displays a three-dimensional (3D) image of the heart and the catheter's location, allowing physicians to record precise location points for orientation along the catheter's path. To further eliminate radiation exposure in the AF patients, the technique uses cardiac magnetic resonance imaging (MRI) instead of computerized tomography (CT) scans for all required imaging prior to the procedure. The novel technique was tested in a pilot study on 21 consecutive patients referred to the UVA Atrial Fibrillation Center, published in the December 2009 issue of Circulation.

"One of the most exciting things about our research is the direct impact on patient care and safety,” said lead author John Ferguson, M.D., an associate professor of cardiology in the UVA School of Medicine. "Cardiac interventions continue to evolve toward lower risk procedures, and this study is another huge step in that direction.”

"Larger studies are needed to confirm the safety of the procedure, but the concept that you can perform complex electrophysiology procedures without any use of X-ray is outstanding,” added Brian Annex, M.D., chief of the UVA division of cardiology. "This is a major goal that is especially critical to those most vulnerable -- patients who would otherwise require excessive radiation due to weight, women of child bearing potential, and of course children and younger adults.”

By using an ultrasound catheter within the heart, the physicians can obtain high resolution images of the heart and other key anatomic structures, providing complete visualization at all times of the catheter's location. This helps the physicians to steer the catheter to affected target areas while avoiding injury to other key cardiac structures.

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