During a cardiac stress test, the heart is put under physical stress to try and detect imbalances in blood flow.
The cardiac stress test, also called the exercise stress test, treadmill test, or simply stress test, is carried out to help a doctor find out how well a patient’s heart is working. When the heart is under the physical stress that exercise causes, it is forced to pump more blood. This extra stress can show whether or not the blood flow is compromised in arteries that feed the heart.
The test can therefore be used to diagnose coronary artery disease and other cardiac conditions, monitor cardiac treatments, and can help predict heart attack risks. Another purpose for the test is helping doctors determine what intensity of cardiac exercise is safe for a patient.
To prepare for a cardiac stress test, patients should not smoke, eat, or drink any alcoholic or caffeinated beverages at least three hours before taking the test. They may also be asked to discontinue medications they are taking. Anyone who has taken a dose of Viagra during the 24 hours prior to the test should notify their doctor.
How the Test Works
The test begins with a patient being fitted with electrodes to measure the heart’s electrical activity, as during a normal echocardiogram. They are also fitted with equipment that can measure their blood pressure during the test.
Next, the patient begins walking on a treadmill (or pedaling on an exercise bike). As they start exercising the ECG and sphygmomanometer will take readings at regular intervals.
The test keeps going until the patient reaches a target heart rate that has been set by the monitoring physician. They will also be monitored for around 15 minutes after the test is over.
The test may be cut short if the patient develops unusual cardiac activity during the test, or if their blood pressure spikes.
Risks of the Cardiac Stress Test
The cardiac stress test does involve some risk, but dangerous complications are very rare. Some patients may faint or collapse, or have chest pain. Heart attack or dangerous heart arrhythmia is extremely rare.
People who are likely to experience these types of dangerous complications during a cardiac stress test are usually not given the test at all, as usually their physician is already aware that complications are likely.
References
American Heart Association: Exercise Stress Test
National Institute of Health MedlinePlus: Exercise Stress Test