Electrocardiography (EKG, ECG) is a test done to record the electrical activity of the heart. Exercise electrocardiography (usually called a stress or treadmill test) is electrocardiography done during exercise to evaluate how the heart responds to the demands of physical activity.

Stress tests may be ordered in the following situations:

• To evaluate unexplained but stable chest pain and determine its cause when coronary artery disease (CAD) is suspected
• To determine the severity of heart disease and the ability of the heart to tolerate exercise in people with known heart disease or in those who have had a heart attack or heart surgery. On the basis of this information, a cardiac rehabilitation program, including appropriate exercise, as well as a plan for low-risk daily physical activities, can be developed.
• To identify abnormal heart rhythms when symptoms such as dizziness, fainting, or palpitations occur during exercise or activity.
• To screen for CAD in a person without symptoms, especially if the person has risk factors for CAD.
• After angioplasty, to see whether a blockage or narrowing of an artery has recurred, especially if chest pain (angina) or other symptoms have returned.
• To evaluate the effectiveness of certain medications or other therapy for irregular heartbeats (arrhythmias) or chest pain (angina).

What does this test evaluate?