Your doctor will diagnose coronary artery disease (CAD) based on:
- Your medical and family histories
- Your risk factors
- The results of a physical exam and diagnostic tests and procedures
No single test can diagnose CAD. If your doctor thinks you have CAD, he or she will probably do one or more of the following tests:
An EKG is a simple test that detects and records the electrical activity of your heart. An EKG shows how fast your heart is beating and whether it has a regular rhythm. It also shows the strength and timing of electrical signals as they pass through each part of your heart.
Certain electrical patterns that the EKG detects can suggest whether CAD is likely. An EKG also can show signs of a previous or current heart attack.
During stress testing, you exercise to make your heart work hard and beat fast while heart tests are performed. If you can't exercise, you're given medicine to speed up your heart rate.
When your heart is beating fast and working hard, it needs more blood and oxygen. Arteries narrowed by plaque can't supply enough oxygen-rich blood to meet your heart's needs. A stress test can show possible signs of CAD, such as:
- Abnormal changes in your heart rate or blood pressure
- Symptoms such as shortness of breath or chest pain
- Abnormal changes in your heart rhythm or your heart's electrical activity
During the stress test, if you can't exercise for as long as what's considered normal for someone your age, it may be a sign that not enough blood is flowing to your heart. But other factors besides CAD can prevent you from exercising long enough (for example, lung diseases, anemia, or poor general fitness).
Some stress tests use a radioactive dye, sound waves, positron emission tomography (PET), or cardiac magnetic resonance imaging (MRI) to take pictures of your heart when it's working hard and when it's at rest.
These imaging stress tests can show how well blood is flowing in the different parts of your heart. They also can show how well your heart pumps blood when it beats.