People with suspected heart pain (angina) must be tested to determine whether they have heart disease and, if so, to gauge its severity. But a word of caution: Avoid having these tests unless you have symptoms. Even though some doctors use one or more of the tests listed below in people without symptoms, that's usually inappropriate, as the tests can be more likely to harm than to help. For example, some expose you to hefty doses of radiation. And in low-risk people, many can register false-positive results that can lead to unnecessary invasive tests and procedures.
Here are several tests and what you need to know about them:
Electrocardiogram (EKG) and stress test In an EKG, electrodes attached to the chest pick up electrical signals from the heart, which are then displayed as a line on a graph. It reveals how fast your heart is beating, whether it's beating in a regular pattern, and the size and thickness of the heart walls. It can even indicate whether you have had a heart attack. A stress test measures the heart's function while it is stressed by exercise (usually walking on a treadmill) or, in some cases, medication.
Some doctors use the tests in people with no heart symptoms as part of a routine exam. "That's generally a bad idea," says Steven Nissen, M.D., chairman of cardiovascular medicine at the Cleveland Clinic in Ohio. "The test is not as accurate in low-risk people and can trigger unnecessary and expensive follow-up." The only exceptions: older airline pilots, bus drivers, or others whose job affects public safety, or middle-aged or older people with multiple heart-risk factors who are just starting to exercise.
But for people with symptoms of heart disease, an EKG combined with a stress test should usually be the first tests ordered. And they should be combined with one of two other tests, too, both of which produce an image of the heart: an echocardiogram (which uses sound waves) or a nuclear test (which uses radioactive material).
Coronary angiography This is the gold standard for confirming heart disease in people with worrisome stress-test results. It involves threading a flexible tube from the groin into the coronary arteries and injecting a dye to make blockages visible on an X-ray. Skipping the stress test and going straight to angiography is justified in people who very likely have clogged arteries or have one of these conditions that make stress testing too risky: unstable angina (heart pain that strikes when you're at rest or gets stronger or more frequent over a short time period), aortic stenosis (narrowing of the heart's main valve), or congestive heart failure (inadequate pumping). If your cardiologist advises going straight to angiography when you have none of those problems, consider a second opinion.
CT angiography This test has almost no role in treating people without symptoms of heart disease and is of limited use even for those who do have them. The test uses multiple X-ray images to create a three-dimensional image of the coronary arteries and reveal plaque deposits. It also measures the amount of calcium in the artery walls, which is correlated with those blockages.
The test might help people at moderate risk of heart disease determine how aggressively they should to treat people at moderate risk for heart disease-whether to prescribe drugs for someone with borderline-high cholesterol, for example. But doctors can usually accomplish the same thing by assessing a patient's risk based on such factors as blood pressure, family history, and in some cases his or her level of C-reactive protein, which reflects inflammation in the arteries. Even in people with suspected heart disease, results of the tests are often so uncertain that they have to be followed up with standard angiography anyway. And they can expose you to potentially dangerous levels of radiation. One study, for example, in The Journal of the American Medical Association, estimated that 1 in every 1,300 60-year-olds who undergoes CT angiography might develop cancer as a result.