MAYWOOD, Ill. - December 4, 2007 - Specialists at Loyola University Health System are the first in the nation to use new ultrasound technology to guide ablation of atrial fibrillation (AF), offering potential improvements in both the precision and safety of this therapy.
AF is the most common type of heart rhythm disorder. In treating AF with catheter ablation, cardiac electrophysiologists traditionally use standard X-ray technology to guide proper placement of radiofrequency energy to ablate the tissues (cause small areas of scarring) in the heart responsible for starting and maintaining the irregular rhythm.
These physicians also generate a computer reconstruction of the heart’s interior, often with the help of pictures obtained from CT or MRI scans done prior to the procedure. While helpful, these reconstructions can be time consuming, difficult to produce, and expose patients to additional radiation. With the newly installed software imaging technology, the CartoSound™ Image Integration Module and SoundStar™ 3D Catheter, Loyola physicians now are able to visualize and create a whole new kind of"map" of the heart in order to perform atrial ablation. They use ultrasound imaging to produce pictures of the heart during the ablation procedure.
The ultrasound technique produces three-dimensional images of the heart’s anatomy within a few minutes at the bedside, and allows real-time, simultaneous monitoring of catheter position and orientation during the procedure, improving both precision and patient safety.
David Wilber, MD, professor of cardiovascular sciences, Loyola University Stritch School of Medicine, said he and his team have used the new technology with 20 patients with"excellent results. While the previous method provided three-dimensional images of the heart, they often lacked sufficient detail. Incorporating CT pictures images from a scan obtained several days earlier provided more detail, but it was difficult to accurately register the older picture to the precise orientation of the heart during the procedure.
“The new 3-D ultrasound images provide a very detailed view of the heart, and most importantly, they reflect the condition of the heart during the procedure. Since the image is generated by the same computer program that tracks the location of the catheter, the points of interest match very closely," Dr Wilber explained.
"This allows very accurate placement of lesions (the ‘scarring’) to assure elimination of the arrhythmia, while avoiding injury to important nearby structures, such as the pulmonary veins or the esophagus. We can now image these structures with unprecedented accuracy continuously during the procedure." “Patients experience shorter X-ray times, and physicians can create more precise ‘heart maps’ for the ablation," Dr. Wilber noted.
He added that "the technology also allows us to map both the right and left sides of the heart from the right atrium (right upper heart chamber) before we must move into the left side to complete the actual ablation (‘scarring’) procedure." Dr. Wilber explained that with less time spent in the left side of the heart, the patient has a decreased risk of having a blood clot form during the procedure that could lead to a stroke. Overall procedure time is decreased by more than 30 minutes, Dr. Wilber added, and the need for additional imaging procedures prior to ablation may be completely eliminated.
"This is a real breakthrough in making these procedures safer, more precise and less taxing on the patient. We are extremely excited about being able to bring these benefits to patients here at Loyola," he said.
AF is the most common irregular heart rhythm disorder in the U.S., affecting about 2.2 million Americans. Approximately 160,000 new cases are diagnosed in the U.S. alone each year. AF may be related to coronary artery disease, thyroid disease, high blood pressure, or other structural heart defects, but often has no detectable cause. If left untreated, AF can cause structural heart changes that diminish heart function. It can also increase the risk of stroke, congestive heart failure and other heart disease. Approximately 50,000 ablation procedures for atrial fibrillation are performed annually in patients who do not respond to medical therapy.