U. technique aiding arrhythmia patients

A new imaging technique puts the University of Utah at the heart of cardiac research.

The research, published in the Journal of the American College of Cardiology, identifies a new way of using magnetic resonance imaging to detect and measure injuries to the heart's left atrium wall in patients who had atrial fibrillation treatment.

Atrial fibrillation is an abnormal heart rhythm, affecting 6 percent of the world's population. Left untreated, the arrhythmia may cause heart failure or stroke. One method of treatment is using radiofrequency ablation, which targets selected heart cells and destroys them, stopping their conduction of extra electrical impulses. The result is a scar on the left atrium wall. Knowing how much of the wall is scarred is important to doctors because without the scarring, atrial fibrillation continues.

"Until now, there has not been an accurate, non-invasive way to assess (left atrium) scar formation," lead author of the study Dr. Nassir F. Marrouche, assistant professor of internal medicine at the U. school of medicine, said in a statement.

Researchers used MRI to determine how much of the left atrium is scarred instead of using more invasive methods, such as inserting a catheter into the heart, Marrouche said. They developed a technique called delayed-enhancement cardiovascular MRI to create three-dimensional images of the left atrium before and after atrial fibrillation ablation. The images are processed and analyzed using special software and algorithms to determine the extent of the heart scar.

"We look at lesions to see if they are deep enough," Marrouche said.

Using the three-dimensional technique, the researchers are able to see a a greater imaging resolution than the two-dimensional images typically used.

Doctors can use this technique to improve planning for radiofrequency ablation procedures by making it easier to identify heart muscles that need to be scarred.

"And it is safe and non-invasive, so it can be repeated without significant risk to the patient," Marrouche said.

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