Diagnosis

Using these and other measures, doctors can determine risk fairly accurately, particularly for men of any age with chronic stable angina. The test has limitations, however, and some are significant. For example, a 2002 study indicated that in patients with suspected unstable angina the chances for a future adverse heart event remain high even if the exercise test shows low risk. In addition, for many reasons, the test is less accurate in women, and an echocardiogram may be a more accurate procedure for them. About 10% of patients, particularly younger people, will have false positive test results. In such cases, test results indicate abnormalities when there are no heart problems.

Echocardiograms

An echocardiogram is a noninvasive test that uses ultrasound images of the heart. This test is more expensive than an ECG, but it can be very valuable, particularly when used with a stress test, to detect the location and extent of heart muscle damage. It appears to be more accurate for women than ECG stress tests, but at this time it is not routinely recommended as a replacement for most women.

Computed Tomography

Computed tomography (CT) scans used alone or with ECG may be used to detect calcium deposits on the arterial walls, which are strong indicators of current and future coronary artery disease. The presence of calcium does not always signify narrowing of the arteries. But, the absence of calcification in the arteries indicates the patient has no risk for heart disease.

Advanced CT techniques are improving accuracy:

Click the icon to see an image of a CT scan.

• Electron Beam Computed Tomography. Electron beam computed tomography (EBCT)  is a CT technique that scans the heart so quickly that the motion of the heart appears frozen. This procedure identifies calcification and stratifies cardiac risk accurately.
• Helical Multislice Computed Tomography. Another CT technique called helical multislice computed tomography (MSCT) angiography is able take pictures of the entire heart in one millimeter slices in the time it takes for a patient to hold one breath. It is highly accurate but exposes the patients to a higher radiation levels than EBCT.