Health & Medicine

New imaging technique improves assessment of blocked arteries

Central Baptist
Central Baptist Courtesy of Central Baptist

Many heart attacks are caused by cholesterol plaque that builds up in blood vessels that supply blood to the heart. This plaque can slow blood flow or block the vessel altogether.

A patient with heart attack symptoms is often rushed to a cardiac catheterization lab so an interventional cardiologist can explore the inside of the heart to check for blocked arteries.

During cardiac catheterization, a catheter (a thin, flexible tube) is inserted into an artery and is passed into the heart. The procedure gives the interventional cardiologist a guided tour of the inside of the heart and the blood vessels.

Obtaining quality images of the insides of blood vessels is crucial for proper diagnosis and treatment of heart disease. During cardiac catheterization, the cardiologist might use an angiogram, during which a dye is injected into the patient's blood vessel to assess the location of and estimate the size of a blockage. The cardiologist also might employ intravascular ultrasound to assess the blockage's structure.

Until recently, angiograms and intravascular ultrasound have been the gold standard in cardiac imaging, but a new technology is helping cardiologists better detect and treat heart disease. Optical coherence tomography uses near-infrared light to create images that are 10 times clearer than older imaging techniques. It lets cardiologists see inside a patient's blood vessel in a way never possible before, allowing them to more quickly and precisely identify blockages and guide treatment.

One of the most important research roles with this technology is in the detection of "vulnerable" plaques, which can rupture without warning, causing a heart attack. A vulnerable plaque shows up as a liquid pool of fat under the lining of the vessel. Looking at the image helps cardiologists decide which treatment is best for the patient. A stent, a small, mesh-like device, might be needed to keep the blood vessel open. The high-resolution, cross-sectional images assist cardiologists in stent selection by providing them with precise measurements. Once a stent is in place, the images can show how the stent is holding the artery open and whether it is positioned correctly against the artery wall.