- The electrocardiogram (ECG) is a diagnostic test to record the electrical activity of the heart. An ECG detects the tiny electrical impulses produced by the heart to make it contract.
- An ECG is commonly used to establish a baseline evaluation of a person’s heart, to detect abnormal heart rhythms, and to investigate newly evolving symptoms, such as chest pain, shortness of breath, or palpitations.
- Stress testing is a painless, safe method to measure how well the heart responds to exertion. An ECG stress test is similar to a resting ECG, but includes exercise.
An electrocardiogram (ECG) stress test monitors a person’s heartbeat at rest and during exercise, most commonly while a person walks on a treadmill. A physician observes the person, monitors the exercise level, and makes recordings until the person’s heart nears a maximum predicted heart rate.
The heart also is monitored during the period of cool-down or recovery that immediately follows exercise. The recordings made before, during, and immediately after an ECG stress test can show subtle changes in heart electrical activity that can help a physician:
- Determine physical fitness,
- Locate areas of the heart that receive an insufficient blood and oxygen supply,
- Reveal heart rhythm abnormalities,
- Evaluate a person’s prognosis after a heart attack,
- Verify the effectiveness of medical and surgical therapies, and
- Determine an appropriate exercise program for people with known heart disease.