Patients with coronary artery blockages may have minimal symptoms and an unremarkable or unchanged EKG while at rest. However, symptoms and signs of heart disease may become unmasked by exposing the heart to the stress of exercise. During exercise, healthy coronary arteries dilate (develop a more open channel) than an artery that has a blockage. This unequal dilation causes more blood to be delivered to heart muscle supplied by the normal artery. In contrast, narrowed arteries end up supplying reduced flow to it's area of distribution. This reduced flow causes the involved muscle to "starve" during exercise. The "starvation" may produce symptoms (like chest discomfort or inappropriate shortness of breath), and the EKG may produce characteristic abnormalities. A stress test is usually considered in the following circumstances:

- Patients with symptoms or signs that are suggestive of coronary artery diseases (CAD).
- Patients with significant risk factors for CAD.
- To evaluate exercise tolerance when patients have unexplained fatigue and shortness of breath.
- To evaluate blood pressure response to exercise in patients with borderline hypertension.
- To look for exercise-induced serious irregular heart beats.

Preparations
- Do not eat heavily prior to the procedure. This reduces the likelihood of nausea that may accompany strenuous exercise after a heavy meal.
- Diabetics, particularly those who use insulin must consult with Physician before taking the test.
-  Specific heart medicines may need to be stopped one or two days prior to the test. Consult with your doctor.
- Wear comfortable clothing and shoes that are suitable for exercise.
- A patient should allow approximately one hour for the entire test, including the preparation.

Doctor On Duty
The Apollo Clinic Bangalore Koramangala
www.koraclinic.com