Exercise ECG (Electrocardiogram): Better Than Ordinary ECG in Indicating Heart Problems

Certain heart problems are usually not plainly evident on an ordinary ECG (electrocardiogram), except when a person is actually having an active episode of such a condition, as in the case of an attack of angina (a condition of discomfort in the chest characterized by intermittent episodes of intense, suffocative pain, and is usually caused by emotional or physical stress). Realizing this fact, what is a better test than an ordinary ECG to have heart problems fully evaluated?

The answer to the above question is exercise ECG, also called stress test - a series of electrocardiograms recorded while a person goes through some physical exertions or exercises. While a person is at rest, it is likely that the results of his or her ordinary ECG test are normal even if a significant heart condition does exist. This was true in the case of my father's first ECG test in late 2001 (my father died of a heart attack in April 2003). Such heart problems may appear on the ECG only if the heart is forced to go through certain amounts of stress.

At the present time, an exercise ECG is often given by doctors to people to determine the existence of heart problems. In an exercise ECG, the person being tested either pedals a stationary bicycle or walks on a treadmill as his/her electrocardiogram is being recorded. The intensity of exercise is gradually increased up to such time as symptoms, like chest pains, develop. It is not only indicating the presence of heart problems that an exercise ECG can do; it can likewise provide a measurable degree of the severity of the condition present.

We have to understand that an electrocardiogram represents the heart's electrical function. When angina is present, the heart is not receiving sufficient amount of oxygen, and this affects its electrical activity. But unless a person is actually having an attack of angina at the time the electrocardiogram is taken, the condition would not appear on the test's result. This is exactly the situation when the usefulness of an exercise ECG comes in. To confirm, for example, if the chest pain being experienced by a person is brought about by angina because of advanced coronary artery disease, an exercise ECG will be very helpful. At the same time, the test will also provide quantitative information as to the exact severity of the disease.

Note, however, that, as an indicator of heart problems, an exercise ECG is also liable to be erroneous. This means that the test can produce both false negative and false positive results. A false negative result shows normal reading inspite of some heart problems being present. A false positive result, on the other hand, indicates abnormal reading on an otherwise healthy person.