A stress test demonstrates the effect that exercise has on your heart. In a standard stress test, the patient walks on a treadmill while being monitored by an electrocardiogram (ECG) and blood pressure readings. This measures your heart's reaction to your body's increased need for oxygen.
The test continues until you reach a target heart rate, unless complications such as chest pain or an exaggerated rise in blood pressure develop. The heart is monitored for 10 to 15 minutes after exercising, or until it returns to its baseline heartbeat.
A stress test is performed to determine causes of chest pain, the exercise capacity of the heart, appropriate exercise levels in those beginning an exercise program, and to identify rhythm disturbances during exercise. There may be additional reasons that your health care provider requests this test.
Nuclear Stress Test
A nuclear stress test shows how well blood flows into the heart when it is at rest and during activity. A radioactive dye is injected into a vein and allows images to be taken that show how blood flows through the bloodstream and into the heart muscle. While the patient is reclined on a table, a camera is used to record images.
The scans are recorded when the heart rate is elevated and again when it is at rest. This allows the cardiologist to compare how well blood flows to the heart when the body is at rest, versus when it is active. In comparison to the standard treadmill stress test, a nuclear stress test is more accurate and provides additional information.
Phatmacologic Stress Test
A pharmacologic stress echocardiogram (echo) is a non-exercise test used to detect coronary artery disease (CAD), or a blockage of blood flow to the heart. The test provides a complete picture of the workings of the heart during periods of rest and exercise.
During the exam, a medicine is given to increase the rate and force of your heartbeat similar to exercise. Then the echo uses high-frequency sound waves (ultrasounds) to look at how the various parts of the heart work. If CAD is present, the stress echo will often note changes in the heart muscle contractions.