Coronary artery disease (CAD) is often used interchangeably with the term coronary heart disease (CHD), but there is a difference. According to the American Heart Association, CHD is usually a result of CAD. This is because plaque grows in the arteries first, eventually limiting blood flow to the heart.
In order to diagnose CAD, certain tests can be done. These can be invasive or noninvasive, depending on the symptoms you have and what your doctor needs to make an accurate diagnosis.
Coronary Angiogram and Cardiac Catheterization
Arteries and veins don't show up on X-rays unless a special dye is injected into the body to make them visible. This dye (contrast solution) is injected by means of a long, flexible tube (catheter). It’s snaked up to the coronary arteries through an incision in the groin, arm, or neck. Arteries narrowed by plaque deposits can be identified easily using X-ray imaging once the dye has been released.
Coronary Calcium Scan
Small deposits of calcium, or calcifications, in the arteries can be an early sign of CAD. A coronary calcium scan can find these deposits early, to help diagnose and catch CAD at its beginning stages. It can even find calcifications before you exhibit any symptoms of CAD. There are two machines that can be used for this: an electron beam computed tomography (EBCT) and multidetector computed tomography (MDCT). During this test, you lie in a scanner machine and the machine will take pictures, similar to X-rays, of your heart.
An electrocardiogram (ECG or EKG) is a test in which a person’s heart rhythm and rate are evaluated by measuring the heart's electrical activity. The test records electrical impulses through electrodes attached to the chest. A rhythm strip graphically represents the electrical activity.
An echocardiogram uses ultrasound technology to create a dynamic picture of heart structure and function. An echocardiogram is sometimes combined with a stress test to allow visualization of the heart during exertion.
Exercise Stress Test
A stress test reveals how well the coronary arteries deliver blood to the heart when it’s put under stress. You may be asked to walk on a treadmill. Stress can also be artificially induced with drugs that increase the heart rate. The heart's performance is tracked using electrocardiography or echocardiography and a blood pressure cuff.