An exercise stress test is an an indirect way of determining how much blockage you have in your heart. Like I mentioned earlier, a heart attack happens when you have complete blockage of the heart, but not everyone presents with an acute occlusion of the vessel. In some patients it can take some time for the vessels to completely narrow to 100% blockage. As the heart continues to narrow patients experience chest pain with exertion, that gets worse over time. So if you are having these symptoms and you go to your doctor and you're not having any evidence of an acute heart attack, a stress test can be done to determine whether or not you have a blockage. Now, a stress test will only pick up a blockage that's greater than 70%. when the blockage is greater than 70% that is your heart and not able to compensate and get enough oxygen to supply the heart. When seeing your doctor for chest pain, he will most likely order a stress test to determine whether or not you have a significant blockage in your heart. Now the results of these tests can take up to a day to come back. So it's not something that you wait for prolonged periods of time to get the results. There are different kinds of stress tests can be done to determine whether or not you have a blockage. These include one, an exercise treadmill test where you just run on the treadmill and you have your heart monitored throughout the duration of the run to determine whether or not there's a significant blockage. A second kind of stress test includes imaging along with exercise. We call this a stress echo or a nuclear stress test. In this situation, a patient runs on the treadmill and gets their heart rate to the maximum level possible. And then the hearts image to see if there are any wall motion abnormalities that will determine whether or not a patient has a blockage. And the third kind of test is a pharmacological nuclear stress tests. That is a way of imaging the heart to look to see if there are any blockages greater than 70%.