Coronary Artery Disease

Diagnosis

At Mayo Clinic, patients benefit from the expertise and experience of a team of heart care specialists. Proper diagnosis begins with a physical exam that includes questions about the patient's family and medical history, including risk factors for coronary artery disease (CAD).

No single test can diagnose CAD. Various tests are used to diagnose CAD and rule out other possible causes of symptoms and signs. Testing may include:

Electrocardiogram (ECG or EKG)

In this noninvasive test, electrodes (sensor patches with wires attached) are placed on the patient's skin to measure the electrical impulses generated by the heart.

Stress Test

During a stress test, the patient exercises on a treadmill or stationary bicycle while being monitored by an electrocardiogram (ECG). For patients who have difficulty exercising, a drug which stimulates the heart may be used to simulate exercise.

Angiogram (Coronary Catheterization)

A liquid dye is injected into the arteries of the heart through a long, thin, flexible tube (catheter) that is threaded through an artery, usually in the leg, to the arteries in the heart. The arteries then become visible on X-ray and videotape, showing areas where coronary arteries may be blocked. The catheter may also be used to push open a blocked artery, a procedure called an angioplasty.

Blood Tests

Certain heart enzymes slowly leak into the blood if the heart has been damaged by coronary artery disease. A blood test identifies these enzymes.

Chest X-ray

An X-ray shows the size and shape of the heart and its blood vessels and can reveal damage caused by coronary artery disease or a heart attack.

Nuclear Scan – SPECT

In this test, trace amounts of radioactive material, such as thallium, are injected into the patient's bloodstream. Special cameras show the flow of blood through the heart and lungs and can indicate where there are abnormalities. Commonly used agents are thallium, sestamibi (Cardiolite®) or tetrofosmin (Myoview®)

PET (Positron Emission Tomographic) Scan

In PET, small amounts of radioactive isotopes are injected into the patient. Depending on the isotope and test conditions (rest or rest/stress), either the flow of blood to the heart muscle or undamaged areas of the heart can be viewed with special cameras.

Echocardiogram (Doppler Echocardiogram)

This test uses sound waves to produce detailed images of the patient's heart. A hand-held device (transducer) held on the patient's chest bounces sound waves off the heart. The waves are reflected back to produce video images of the heart's size, structure and motion. The echocardiogram can also be used to measure the heart's blood volume and the speed and direction of blood flow through the heart.

Transesophageal Echocardiogram

After the patient is sedated, a tube with a transducer (sound device) is inserted down the esophagus from the throat to the stomach. Because the esophagus passes close to the heart, the transesophageal echo provides an even more detailed image of the heart's size, structure and motion.

64-Detector CT Scan

In some patients, the coronary arteries can be visualized with a special CT angiogram using the 64- detector CT scanner. Mayo Clinic in Minnesota installed the first 64 detector CT scanner in the United States. Read more about the 64-detector CT scanner.

Electron-Beam Computed Tomography (EBCT).

This test, also called an ultrafast CT scan, can detect calcium within plaques that narrow and block coronary arteries. Most, but not all, plaques contain some calcium. Substantial calcium build-up in and around the coronary arteries can indicate coronary artery disease.