Exercise stress testing is a test to evaluate for the presence of coronary artery disease by stressing the heart with exercise. Patients are usually exercised on a treadmill or bicycle to increase their heart rate. An electrocardiogram is monitored throughout looking for changes that may signify coronary disease. The blood pressure and heart rate are also monitored. Many times the patient is injected with an imaging agent (technetium or thallium) during exercise which helps determine if there are any blockages in the coronary arteries (this is referred to as a nuclear stress test). For patients who are unable to exercise there are agents that can be administered (adenosine, dobutamine, or persantine) instead of exercise.