Ultrasound tool seen as a 'breakthrough' for AF
Safety, precision reported
Early feedback on a new ultrasound technology suggests that it is bringing important improvements to the table for the treatment of heart-rhythm disorders.
In fact, after using the system on just 30 patients, clinicians from Maywood, IL-based-Loyola University Health System report that the new 3-D, real-time, mapping system, produced by Diamond Bar, CA-based Biosense Webster, is now their method of choice for guiding ablation of atrial fibrillation (AF). They report they no longer need to subject patients to the radiation exposure associated with CT prior to such procedures.
"In a series of about 10 minutes, you can [produce] somewhere around 15 to 20 two-dimensional images, and you get a really nice picture that gives you [nearly] all the detail that you can get from a CT scan without any radiation," explains David Wilber, MD, FAHA, FACC, professor of cardiovascular sciences at Loyola University's Stritch School of Medicine. "And it is immediate in the sense that it reflects the heart's condition within the past few minutes as opposed to whenever the CT scan was done, so for a procedure it is extremely helpful because it reflects current anatomy and volume."
The system consists of the Cartosound Image Integration module, Soundstar 3D Catheter, and the Carto XP Navigation System, and it represents the first integration of intracardiac echocardiography (ICE) with 3-D mapping, explains Nancy DeMars, the product director for imaging at Biosense Webster. "The ultrasound catheter utilizes an embedded position sensor to display location and beam orientation on the Carto XP System, which enhances visualization of ICE images and ablation catheter location," she says.
When used with the CartoMerge Image Integration Module, DeMars points out that the ICE images can be merged with previously acquired CT or MRI images and create a highly detailed picture. However, Wilber has found that this extra step is superfluous. "It makes the CT scan unnecessary for the purposes of this procedure, and that is wonderful because the CT scan has significant radiation exposure, and an echo has no ionizing radiation, so to me, it is a huge step forward," says Wilber.
"If you take a predesigned image from a CT scan a couple of days ahead of time, the only way you can register it and get it into the right orientation to match the patient's position on the day of procedure is that you have to acquire a lot of information in the left atrium, so you have to be in the left atrium," he says. However, being in the left atrium creates potential problems in the form of blood clots, so a key advantage of the ultrasound technology is that images can be collected from the right atrium which is very benign, according to Wilber. "This has already become our preferred option, so we very quickly went from seeing how it works to concluding that this is so much better than anything else we had."
Wider applications possible
While Loyola Health System was the first center to use the new technology, it is now being used by electrophysiologists and interventional cardiologists at a handful of other centers including the Mayo Clinic in Rochester, MN, Brigham and Women's Hospital in Boston, and The Cleveland (OH) Clinic. Further, DeMars indicates that sales have exceeded the company's initial expectations since Biosense Webster began making the system available to customers in October 2007. The list price for the Cartosound Module is $75,000; the 3-D catheter is $2,950.
Thus far, the system has been used only for simple ablation procedures; however Wilber indicates that it potentially could be applied to all the things that people use cardiac ultrasound for, such as placing of devices in the left atrium, closing atrial septal defects, and plugging up left atrial appendages. The system's potential in the treatment of AF alone is huge, however, given that AF is the most common irregular heart beat rhythm disorder in the country, affecting more than two million Americans. Medical therapy often is effective for AF, but approximately 50,000 ablation procedures are performed each year in cases where medical therapy has been unsuccessful.
As one of the technology's initial users, Wilber is involved with training other clinicians in how to use the Cartosound system, but he indicates that this is not a lengthy process for anyone with experience in using phased array echo procedures. "You basically show people how to use it, and how to acquire the images, but it is so simple that, in fact, it doesn't require much training," he says.
Early feedback on a new ultrasound technology suggests that it is bringing important improvements to the table for the treatment of heart-rhythm disorders.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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