V. STABLE AND UNSTABLE ANGINA
2. Exercise Stress Test
A treadmill exercise test using the Bruce protocol is used worldwide to detect myocardial ischemia that is pre¬cipitated by exercise. The ECG tracing during exercise-induced ischemia shows typical features that can be easily recognized. Although the test is of little value in screen¬ing asymptomatic patients who are at low risk for CAD, it is most useful for patients who are symptomatic. False-positive tests are not uncommon in women.
3. Cardiac Nuclear Scans
Cardiac nuclear scans performed following treadmill exercise or during myocardial-induced ischemia provoked by dipyridamole, adenosine, or dobutamine are particu¬larly useful. These tests are not sufficiently sensitive or specific, however, and further technologic advances are necessary. Despite the use of these scans for more than 30 years, further sophistication is necessary. There is room here for further research and development particularly because these tests are widely used and are often inaccurate.
4. Coronary Angiograms
For some patients, coronary arteriography may be required. Arteriography is the gold standard for detecting obstruction of coronary arteries by atheroma. The exact site and location of the obstruction can be identified for interventional therapy with balloon angioplasty, stent implantation, or bypass surgery. For a further description of tests, see the chapter Tests for Heart Diseases.