An exercise stress test is a screening tool used to test the effect of exercise on your heart.
It helps physicians find out how well the heart handles stress. A cardiac stress test is a medical test that indirectly reflects arterial blood flow to the heart during physical exercise. In contrast to resting ECG, during this test body works harder and it requires more oxygen and the heart has to pump more blood to match with increased demand of the body. Continuous ECG monitoring is done during the test. The test can exhibit adequacy of blood supply to the heart through ECG changes.
Reasons why an exercise stress test may be performed include:
Stress tests are generally safe. The risk is similar to what you would expect from any streneous exercise. Some patients may have chest pain or may faint or collapse. A heart attack or dangerous irregular rhythm is rare. Persons who are likely to have such complications are usually already known to have a weak heart, so they are not given this test. Experienced medical staff is in attendance to manage the rare complications.
The study will help confirm the patient in stable condition or require modification of the treatment or recommend for additional testing such as cardiac catheterization, Echo stress test or a Nuclear stress test.
Treadmill test sensitivity is 73-90% and specificity 50-74% (Modified Bruce protocol).Approximately 10% of the patients may have “false positive” test when the result is falsely abnormal in patient without coronary artery disease. Rarely It could also be “false negative” test when the result is normal in patient with coronary artery disease.
This test is done at a medical center or health care provider's office. The technician will place total of 10 electrodes; 6 on the chest wall & 4 on limbs. It is fixed on the chest by sticking patches. These are attached to an ECG monitor which displays continuous electrical activity of your heart during the test.
You will walk on a treadmill or pedal a stationary exercise bicycle ergometer. Speed & incline of treadmill will be increased every 3 minutes. It is like walking fast or jogging up a hill. The level of mechanical stress is progressively increased by adjusting the difficulty & speed. While you exercise, the activity of your heart is monitored with an electrocardiogram (ECG) and your blood pressure readings are also measured. You will be monitored for 10-15 minutes after exercising, or until your heart rate returns to baseline. The total time of the test is around 60 minutes.
The test continues until: