GXT/MST Instructions and Info

Pretest instructions

Please allow for one and a half or two hours to complete the test.

Please be on time.

Avoid strenuous activity for 12 hours prior to testing.

Eat a light meal on the day of the test. Avoid fatty foods and caffeine.

Do not smoke for at least two hours prior to testing.

Continue all your medications as usual unless otherwise directed by your physician. Please bring a list of your medications with you. For any questions about your medications, please contact your physician’s office.



Please wear or bring appropriate clothing:

Sneakers, flats, or walking shoes are acceptable. Slippers are not acceptable.

MEN: Gym shorts, Bermuda shorts, loose-fitting trousers, a wind suit or sweatpants are all acceptable.

WOMEN: Gym shorts, walking shorts, slacks, a wind suit, or sweatpants are all acceptable. One-piece undergarments and panty hose are not advised.

Rubberized sweat suits are not permitted.



Bring your insurance cards and driver’s license for insurance purposes.

In the event you cannot keep your scheduled appointment, please call and cancel.

GXT Information

A graded exercise test is a type of stress test designed to evaluate your heart and blood pressure response during vigorous activity. Treadmill or stationary bike activity can be used. A motorized treadmill is usually preferred. The goal of the test is to raise your heart rate to a predetermined level during exercise. EKG and blood pressure monitoring during the activity are used to pick up abnormalities that may indicate heart disease. The treadmill is programmed to start slowly and then increase speed and incline at 3 minute intervals. Once you reach your target heart rate or maximum heart rate, the test is stopped. If you become fatigued or distressed before reaching this target heart rate, the test will be stopped early.

MST Information

A metabolic stress test is a type of stress test designed to evaluate how different organ systems interact during vigorous activity. Useful information about the cardiovascular, respiratory, and musculoskeletal systems can be obtained. Psychological and conditioning factors can be observed. Frequently, a determination of which organ system is most limiting and causing shortness of breath can be made. The test has many indications. Some of these are listed below:

1. Evaluate shortness of breath which does not have an apparent cause otherwise
2. Preoperative assessment before lung surgery
3. Determine the degree of fitness for athletes
4. Assessment and followup of interstitial (scarring) lung disease

The test is performed using a treadmill or exercise bike for activity. We use a treadmill in our office. (Please see the pretest instructions at the top of the page.) EKG leads and a blood pressure cuff are placed. You will breath through a mouthpiece during activity. Normal room air oxygen levels are supplied through the mouthpiece and every second or third breath you take is computer analyzed during the activity. We prefer, if possible, to place a small IV catheter in your radial (wrist) artery prior to starting the exercise. The tissue around the artery is numbed first with lidocaine so the procedure does not hurt. The treadmill is programmed to increase in speed and incline with time. Depending on your predicted level of activity, we may program for aggressive exercise or for lighter exercise. We ask that you exercise until you are too tired to continue. If you go above your maximum, safe heart rate or if we detect a problem during exercise, then your test may be stopped early.

During the activity, data is collected is various ways. Blood is drawn from the artery. Heart rate, EKG tracings, and blood pressure are all monitored. Carbon dioxide and oxygen levels are monitored continuously. All this information is printed by the computer for interpretation.

After exercise, there is a cool down period where more blood is drawn and heart rate and blood pressure are still monitored. After this, the arterial IV and EKG leads are removed and the test is over.

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