I learn something here every day. I read a little further seeking clarification and this is what I found on the types of stress tests explained:
"What Are the Types of Stress Tests?
There are many different types of stress tests, including:
Treadmill stress test:
As long as you can walk and have a normal ECG, this is normally the first stress test performed. You walk on a treadmill while being monitored to see how far you walk and if you develop chest pain or changes in your ECG that suggest that your heart is not getting enough blood.
Dobutamine or Adenosine Stress Test:
This test is used in people who are unable to exercise. A drug is given to make the heart respond as if the person were exercising. This way the doctor can still determine how the heart responds to stress, but no exercise is required.
An echocardiogram (often called "echo") is a graphic outline of the heart's movement. A stress echo can accurately visualize the motion of the heart's walls and pumping action when the heart is stressed; it may reveal a lack of blood flow that isn't always apparent on other heart tests.
Nuclear stress test:
This test helps to determine which parts of the heart are healthy and function normally and which are not. A small amount of radioactive substance is injected into the patient. Then the doctor uses a special camera to identify the rays emitted from the substance within the body; this produces clear pictures of the heart tissue on a monitor. These pictures are done both at rest and after exercise. Using this technique, a less than normal amount of thallium will be seen in those areas of the heart that have a decreased blood supply.
Preparation for these types of stress tests will vary from preparation for the exercise stress test. Ask your doctor about any specific instructions."