Q & A: Exercise Stress Tests
APRIL 30, 2019
What Stress Tests Can Reveal About Heart Health
Exercise stress tests have been used for decades to help cardiologists diagnose heart disease. Sometimes called treadmill tests, they show how well the heart handles work. We talked with Dr. Ernest Gervino, Director of the Clinical Physiology Laboratory, to learn more.
What can an exercise stress test reveal?
Exercise stress tests are used to challenge the heart and can help determine if there are any significant blockages in coronary blood flow (which can lead to a heart attack), and can also help to identify irregular heart rhythms. They are also used to monitor the effects of cardiac therapy, determine safe levels of exercise and determine the heart’s functional capacity—how well it is working.
What symptoms might indicate the need for a stress test?
The most common reasons for prescribing a non-imaging stress test are discomfort in the chest, arm, neck or back that could be a sign of angina. Angina is chest pain that develops when the heart muscle isn’t getting enough blood, which is more likely during physical activity.
During the test, the patient walks on a treadmill so that the heart works progressively harder while the patient is closely observed for symptoms of chest discomfort or fatigue. At the same time, an electrocardiogram (ECG) records the heart’s electrical rhythms and blood pressure is measured. Abnormalities in blood pressure, heart rate, ECG measures or worsening physical symptoms could indicate a problem.
Patients who are unable to walk on a treadmill can be given medication that challenges their heart without exercise.
Is a stress test part of an annual checkup?
No. At one time, it was common for patients to undergo annual stress tests, but that is no longer the case. Physician groups, including the American College of Cardiology, advise that exercise stress tests are of little value for patients who don’t have symptoms or strong risk factors for heart disease.
What are imaging stress tests?
Sometimes more advanced stress testing is needed to help in evaluating a patient’s heart health. For example, the patient may have symptoms but their treadmill stress test did not reveal any concerns. Or, their treadmill test may have shown ECG changes but they have no symptoms.
In these cases, the physician might combine an exercise stress test with an imaging test to increase sensitivity and provide additional information. Two of the most commonly used imaging tests are nuclear perfusion imaging and echocardiography (cardiac ultrasound).
How are test results interpreted?
Test results can be:
- normal, meaning a serious blockage is unlikely;
- abnormal, meaning a blockage is likely; or
- undetermined, meaning that the results are unclear
We always remind patients that about 10 to 15 percent of patients with normal results may have coronary artery disease and that, conversely, up to 15 percent of patients with abnormal results don’t have heart disease.
The most important thing any patient should do is to have a conversation with their physician about any symptoms they are having. If the patient is unable to have that conversation and has experienced chest, arm, back or neck pain for more than 15 minutes, they should proceed to their nearest emergency department for further evaluation.