New 3-D Mapping System Helps UA Cardiologists Improve Targeted Treatment for Arrhythmia Patients

03/02/15

For select patients with heart-rhythm problems, radiofrequency catheter ablation can be an effective treatment to restore a normal heart rhythm. For atrial fibrillation, the most common arrhythmia seen in clinical practice, catheter ablation therapy currently offers only modest success rates.

Determining the appropriate sites for ablation in patients with atrial fibrillation when symptoms are not well controlled by medications has been a challenge for electrophysiology cardiologists.

Now, a new 3-D mapping technology enables University of Arizona Sarver Heart Center electrophysiology cardiologists to precisely locate so-called rotor sites, electrical spiral waves that allow arrhythmias to continue.

“By seeing these rotors more precisely, we can target them with ablation catheters and improve the success of the procedure,” explained Julia H. Indik, MD, PhD, associate professor of medicine at the UA Sarver Heart Center. “This new technology can process electrical signals from multiple locations in the heart simultaneously and then project the rotor site, approximately three to six sites per patient, onto our three-dimensional mapping system.”

“Typical success rates [for current catheter ablation therapy] are 90 percent or greater for common arrhythmias, such as atrial flutter and supraventricular tachycardia. For atrial fibrillation, however, the success rates are less – only about 50 to 70 percent of patients can expect an improvement in symptoms,” said Peter Ott, MD, associate professor of medicine at the UA Sarver Heart Center. “It’s important to note that catheter ablation therapy typically is not considered to be a cure for atrial fibrillation.

“Targeted ablation at discrete rotor sites can result in abrupt termination of atrial fibrillation in two-thirds of patients and has been shown to improve the long-term outcome of this procedure,” added Dr. Ott.

Catheter ablation treatment of atrial fibrillation is a complex procedure. It requires placement of multiple catheters simultaneously inside the upper heart chambers and can take two to three hours, sometimes longer. Two to 3 percent of patients experience complications, some of which are serious and include the risk of stroke, heart injury and potentially life-threatening bleeding events. These complications occur more frequently in elderly patients, those in frail health, and of petite stature, added Dr. Ott.

In 1985, Frank Marcus, MD, emeritus professor of medicine and cardiology at the UA Sarver Heart Center, published his discovery that radiofrequency energy was a safer substitute for direct-current (DC) energy in eliminating sites of arrhythmias in the heart. This technology now is used worldwide on a daily basis to treat different types of arrhythmias.

More information on atrial fibrillation and other heart rhythm disorders, their diagnosis and treatment options, as well as contact information for the UA Sarver Heart Center, is available on the website: www.heart.arizona.edu/Heart-rhythm

The 3-D mapping technology currently is available in Southern Arizona only at Banner – University Medical Center Tucson.

Did you know?

Atrial fibrillation, the most common heart-rhythm abnormality, affects 2 to 3 million people in the United States, a number projected to increase to 12 to 15 million by 2050 as the population ages. The prevalence of atrial fibrillation increases with age in both men and women and it is seen more frequently in patients with high blood pressure, underlying heart disease and sleep apnea. The treatment of atrial fibrillation includes medication, catheter ablation and possibly pacemakers.

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The University of Arizona Sarver Heart Center’s 135 members include faculty from cardiology, cardiothoracic surgery, pediatric cardiology, neurology, radiology, endocrinology, emergency medicine, nursing, pharmacy and basic sciences. The UA Sarver Heart Center emphasizes a highly collaborative research environment, fostering innovative translational or “bench-to-bedside” research and working toward a future free of heart disease and stroke.