Test Provides Look at Sick Hearts

Friday, November 17th 2000, 12:00 am

By: News On 6

A new diagnostic technique can give doctors a look into the heart wall and tell them more accurately which heart attack patients will benefit from bypass surgery or angioplasty, a study found.

The technique, known as contrast-enhanced magnetic resonance imaging, can see through the entire thickness of the heart wall â€” typically four-tenths of an inch â€” and tell doctors which tissue can be saved and which is dead. The common scanning techniques now in use read only the surface.

The new technique ``is so sensitive that we can pick out heart attacks in people who didn't even know they had one,'' said Dr. Raymond Kim, who led the study.

The researchers at Northwestern University and Siemens Medical Systems, both in Chicago, studied 50 patients with coronary artery disease. Their findings were reported in Thursday's New England Journal of Medicine.

The new technique combines traditional magnetic signal tests and a common dye with new software to yield more sensitive readings.

The researchers divided the heart images into 72 segments. In 78 percent of segments with no indication of dead tissue, heart function improved with a bypass or angioplasty, which send more blood to the heart.

In segments where more than 75 percent of the tissue looked dead, just 2 percent pumped more strongly after bypass or angioplasty.

``The data are exciting and quite promising,'' said Dr. George Beller, a University of Virginia cardiologist who wrote an accompanying editorial.

However, he said more research is needed on sicker patients.

Kim said the enhanced MRI technique may come to replace the widely used imaging techniques of echocardiography and tomography for many patients.