Stress Test

A stress test (also called treadmill or exercise electrocardiogram [ECG]) is a test that is given while a person walks on a treadmill or pedals a stationary bike to monitor the heart during exercise. During a stress test, the heart is monitored by an ECG test that records electrical activity, showing abnormal rhythms and sometimes detecting heart muscle damage.

Breathing and blood pressure rates are also monitored during a stress test. Together, they can be used to detect coronary artery disease and to determine safe levels of exercise following a heart attack or heart surgery.

During the test, electrodes (small pads) are placed on your upper body and a blood pressure cuff is placed on your arm to monitor your heartbeat and blood pressure during and after the test. You are then asked to exercise for several minutes. The exercise may be easy at first, but it will slowly get harder, with an increase in speed and incline every few minutes.

Be sure to tell your health care provider if you feel any of the following:

• Chest, arm or jaw discomfort
• Severe shortness of breath
• Fatigue
• Dizziness
• Leg cramps or soreness

Nuclear stress test

Cardiac nuclear imaging measures the flow of blood in your heart at rest and during exercise. It also measures how well the heart muscle squeezes and pumps. The test is also sometimes called a perfusion scan or a SPECT MPI (single photon emission computed tomography myocardial perfusion imaging). 

For the scan, a small amount of radioactive material, called tracer, is delivered into the bloodstream. A special camera then scans the tracer in the blood as it flows through the heart muscle. Areas of the heart that have good blood flow absorb the tracer. Areas that are not getting enough blood will not absorb the tracer. This can be a sign of a blocked artery or damage from a heart attack. The tracer leaves your body within hours.