What you can expect

A stress test usually takes about an hour, including both prep time and the time it takes to do the actual test. The actual exercise test takes only around 15 minutes. You'll usually walk on a treadmill or pedal a stationary bicycle. If you aren't able to exercise, you'll receive a drug through an IV that mimics the effect of exercise on your heart.

Before a stress test

Your doctor will ask questions about your medical history and how often and at what level of intensity you exercise. This helps determine the amount of exercise that's appropriate for you during the test. Your doctor will also listen to your heart and lungs for any health problems that might affect your test results.

During a stress test

A nurse or technician will place sticky patches (electrodes) on your chest, legs and arms. Body hair may be shaved to help them stick. Wires connect the sensors to a computer, which records your heart's electrical activity. A cuff on your arm checks your blood pressure during the test. You may be asked to breathe into a tube during the test to show how well you're able to breathe during exercise.

You'll probably exercise on a treadmill or stationary bike, starting slowly. As the test continues, the exercise gets more difficult. You can use the railing on the treadmill for balance. Don't hang on tightly, as this may affect the results.

You continue exercising until your heart rate has reached a target level or until you have signs and symptoms that don't allow you to continue. These signs and symptoms may include:

• Moderate to severe chest pain
• Severe shortness of breath
• Abnormally high or low blood pressure
• An abnormal heart rhythm
• Dizziness
• Fatigue
• Certain changes in your electrocardiogram

If you can't exercise during the stress test, you'll be given a drug through an IV that increases blood flow to your heart. You might feel flushed or short of breath, just as you would if you were exercising. You might get a headache.

You and your doctor will discuss your safe limits for exercise. You may stop the test anytime you're too uncomfortable. Your doctor will watch your heart activity and stop the test if there are any concerns.

After a stress test

After you stop exercising, you may be asked to stand still for several seconds and then lie down for a period of time with the monitors in place. Your doctor can watch for any problems as your heart rate and breathing return to normal.

When your exercise stress test is complete, you may return to your normal activities unless your doctor tells you otherwise.