There are a couple of definitions for stress test, including actual tests that people can take to score their emotional stress levels. More commonly in medicine, the stress test refers to measurement of cardiac function, when the heart is working hard or under “stress.” This shouldn’t be taken as negative stress to the heart, but simply means a demand on the heart to work harder either through exercise, or through injection of a medication.
A number of reasons exist why doctors, and often cardiologists, would order a stress test. These could be to rule out or rule in conditions like greater risk of heart attack, abnormal heart rhythm patterns, or presence of diseased coronary arteries. Sometimes patients present with symptoms like difficult breathing or heart pain that aren’t easily explained and the test could be used to diagnose a cause or to rule out the heart as the cause of symptoms.
Several different variations of the stress test exist. In the exercise electrocardiogram (EKG) test, people will use a treadmill or bicycle to increase heart rate while the EKG is carefully watched for any irregular signs. The test usually begins with a resting EKG reading, and then a person will continue to wear EKG monitoring stickers as they begin to exercise.
Typically the exercise portion of this test isn’t that long, though it may feel long if people don't exercise regularly. Generally most people elevate their heart rate up to the desired area in about 10 minutes, and EKG readings will be taken as this occurs. Occasionally this test finishes with an echocardiogram or sonogram of the heart, but this is not always the case.
An echocardiogram stress test is slightly different and may be performed in several ways. This looks at pictures of the heart when it is working, and usually begins with administration of medications like dobutamine or adenosine. These medications replace exercise and cause the heart to beat very fast, as if exercise were occurring, which can be an uncomfortable, though fortunately short-lasting sensation. Both EKG and echocardiogram may be performed, and as with the exercise test, vitals like blood pressure are monitored carefully.
Since there are so many possible variations of the stress test, it is difficult to instruct people on what to expect or how they should prepare. The best instruction usually comes from the cardiologist performing the test. In general it might be said that if the test involves physical activity, people should wear comfortable clothes and shoes that are suited to a workout. If an echo is involved, women will be asked to remove bras, so wearing one that is easy to remove makes good sense. Most tests do ask people not to eat for 12 hours prior to testing, and it may be wise to schedule these tests for early morning to avoid daytime fasting.
Another area that cardiologists should fully explain to patients is that they can and should voice discomfort. If testing suddenly involves acute pain, even if not heart related, patients can stop. Most will have the option of doing other forms of stress tests if exercise is uncomfortable or too difficult to do.
The last thing that people may want to know is if an order for a stress test always means a diagnosis of cardiac problems. It doesn’t. Lots of people have these tests and are shown to be in very good shape. However, should the test reveal cardiac issues, people may take comfort in the fact that catching heart problems early is far more favorable when it comes to treatment outcome.