GEORGE A. BELLER, MD, MACC: Angina is diagnosed clinically first by getting a good history, where the characteristics of the pain are thought to be a high probability by the doctor or nurse interviewing the patient that it's angina. It is most often confirmed by a stress test, and this is usually done on a treadmill, and with monitoring the electrocardiogram during the exercise stress.
But most often, there has to be a second test done with the treadmill test, which is an imaging test, and the most common one used is a nuclear cardiology test called a spec scan, or a myocardial perfusion scan, in which the heart blood flow can be visualized with a special camera when an agent, an imaging agent is injected during the treadmill test. And after the test is over, the person is put under the camera, and areas that didn't get enough blood flow, that caused the angina, can be actually seen on the pictures taken with this special camera.
SPENCER B. KING, III, MD: In addition to all that, there are tests that measure directly the arteries. The common test is the coronary arteriogram, which is an invasive test. We put a catheter in and inject a dye or a contract media, we call it, into the arteries, use x-ray to create images, and we can see blockages in the arteries.
More recently, there are noninvasive ways, such as computerized tomography that help us see the arteries. There's magnetic resonance imaging (MRI) that can help us see these. And these evolving techniques are usually measured against the gold standard, which is the coronary arteriogram. But there are a host of ways to investigate angina. All of these are not always necessary, but they're all available to help us understand whether this is in fact due to coronary artery blockage.