Before starting to exercise, the patient receives an injection of thallium201, a radioactive chemical, which is taken up by normal heart muscle cells. Angiography is an invasive test that may be performed on patients who have very incapacitating angina that does not respond to medical therapy and for planning surgical procedures. A narrow tube is inserted into an artery, usually in the leg or arm, and then threaded up through the body to the coronary arteries. A dye is injected into the tube and an x-ray records the flow of dye through the arteries. This process provides a map of the coronary circulation, revealing any blocked areas.
Allergic reactions can also occur.
Many experts believe this procedure is overused. The reports are distinguished from other information sources available to patients and health care consumers by their quality, detail of information and currency. These reports are not intended as a substitute for medical professional help or advice but are to be used only as an aid in understanding current medical knowledge. A physician should always be consulted for any health problem or medical condition. The reports may not be copied without the express permission of the publisher.