High-tech imaging software locates more accurately the abnormal electrical impulses that produce heart arrhythmias

Loyola University Health System is one of the first hospitals in the United States to employ new high-tech imaging software - in conjunction with a three-dimensional cardiac mapping and navigation system - to locate more accurately the abnormal electrical impulses that produce heart rhythm disturbances (arrhythmias). This technology represents a major breakthrough in treating complex arrhythmias.

The new software, Biosense Webster, Inc.'s CartoMerge Image Integration Module, is used with the company's electrophysiological navigation system to merge computed tomography (CT) scan images onto 3-D electro-anatomical maps to achieve a more realistic picture of the heart's anatomy and electrical activities.

"We're using the new technology to improve further the precision of catheter ablation, a non-surgical procedure that destroys tissues that generate abnormal electrical impulses," said Dr. David Wilber, professor of cardiovascular sciences, department of medicine, Loyola University Chicago Stritch School of Medicine; and director of cardiology, Loyola University Health System, Maywood, Ill. "For the first time, we can track the movement of the catheter within an exact representation of the patient's heart. As a result, we can move the catheter more confidently and precisely to specific areas of the heart responsible for generating the arrhythmia, improving ablation success and lowering procedure related risks."

All types of arrhythmias can be treated using the new high-tech software in conjunction with the navigation system, but it is especially effective for atrial fibrillation, a disorder of the electrical system in the atria, or upper chambers of the heart. The condition affects more than two million people in the U.S.

With atrial fibrillation, electrical signals are so chaotic and fast that the atria may beat more than 300 times per minute, in comparison with the typical 60 to 80 beats per minute. This restricts the heart's ability to pump blood, causing reduced blood flow and increasing one's risk of clot formation and subsequent stroke.

Wilber and his colleagues use the new technology to improve the accuracy of atrial fibrillation ablation, a procedure that builds a moat or fence around the pulmonary veins and other parts of the left atrium to block the abnormal electrical impulses from reaching the rest of the heart. These veins, which are sized and shaped differently in each person, play an important role in generating atrial fibrillation.

"The catheter ablation procedure for atrial fibrillation is more complex than for most other arrhythmias," said Wilber. "Success depends on a detailed and very accurate depiction of the anatomy of the left atrium and pulmonary veins. The new technology works best in this situation because it helps us identify the margins of the pulmonary vein more clearly. This helps to improve accuracy and reduce procedure time. In addition, the CT picture of the heart provides unparalleled details of anatomy. These detailed pictures can be used as a realistic background to guide the ablation."