Making the Diagnosis
An electrocardiogram (ECG) detects abnormal electrical cardiac charges. In someone who has had heart damage, the electrical signals that keep the heart beating change as they pass through damaged tissue. This can be detected and measured on an ECG.
An exercise electrocardiogram (or stress test) checks your heart for changes during periods of activity, and it can also show if the coronary arteries are too narrow. An exercise stress test is performed on a treadmill or a stationary bicycle while hooked up to an ECG. A thallium scan allows imaging of blood flow in the heart during exercise. This involves injecting a very small dose of radioactive substance into the bloodstream, which is followed through the heart by a special camera.
With angina, abnormalities in the ECG may only occur while the person is having an angina attack. Some people have "silent angina," where even an attack brings no symptoms. To detect this, you may be asked to wear a monitor for 24 hours. The ECG tape is analyzed for irregularities, and then compared with a detailed diary, in which you record your daily activities and any unusual symptoms.
Coronary angiography (or arteriography) is a test used to explore the coronary arteries. A fine tube (catheter) is put into an artery of an arm or leg and passed through the tube into the arteries of the heart. The heart and blood vessels are injected with contrast dye, which is then filmed with an X-ray while the heart pumps. The picture that is seen, called an angiogram or arteriogram, will show problems such as a narrowing or blockage caused by atherosclerosis.