What constitutes CAD...?
This is what I found:
How Is Atherosclerosis Diagnosed?
Your doctor will diagnose atherosclerosis based on your medical and family histories, a physical exam, and results from tests.
Specialists Involved
If you have atherosclerosis, a primary care doctor, such as an internist or family practitioner, may handle your care. Your doctor may recommend other health care specialists if you need expert care. These specialists may include:
A cardiologist. This is a doctor who specializes in diagnosing and treating heart diseases and conditions. You may see a cardiologist if you have coronary heart disease (CHD) or coronary microvascular disease (MVD).
A vascular specialist. This is a doctor who specializes in diagnosing and treating blood vessel problems. You may see a vascular specialist if you have peripheral arterial disease (P.A.D.).
A neurologist. This is a doctor who specializes in diagnosing and treating nervous system disorders. You may see a neurologist if you've had a stroke due to carotid artery disease.
Physical Exam
During the physical exam, your doctor may listen to your arteries for an abnormal whooshing sound called a bruit (broo-E). Your doctor can hear a bruit when placing a stethoscope over an affected artery. A bruit may indicate poor blood flow due to plaque buildup.
Your doctor also may check to see whether any of your pulses (for example, in the leg or foot) are weak or absent. A weak or absent pulse can be a sign of a blocked artery.
Diagnostic Tests
Your doctor may recommend one or more tests to diagnose atherosclerosis. These tests also can help your doctor learn the extent of your disease and plan the best treatment.
Blood Tests
Blood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels may be a sign that you're at risk for atherosclerosis.
EKG (Electrocardiogram)
An EKG is a simple, painless test that detects and records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart.
An EKG can show evidence of heart damage due to CHD and signs of a previous or current heart attack.
Chest X Ray
A chest x ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. A chest x ray can reveal signs of heart failure.
Ankle/Brachial Index
This test compares the blood pressure in your ankle with the blood pressure in your arm to see how well your blood is flowing. This test can help diagnose P.A.D.
Echocardiography
Echocardiography (echo) uses sound waves to create a moving picture of your heart. The test provides information about the size and shape of your heart and how well your heart chambers and valves are working.
Echo also can identify areas of poor blood flow to the heart, areas of heart muscle that aren't contracting normally, and previous injury to the heart muscle caused by poor blood flow.
Computed Tomography Scan
A computed tomography (CT) scan creates computer-generated pictures of the heart, brain, or other areas of the body. The test often can show hardening and narrowing of large arteries.
A CT scan also can show whether calcium has built up in the walls of the coronary (heart) arteries. This may be an early sign of CHD.
Stress Testing
During stress testing, you exercise (or are given medicine if you are unable to exercise) to make your heart work hard and beat fast while heart tests are done.
When your heart is working hard and beating fast, it needs more blood and oxygen. Plaque-narrowed arteries can't supply enough oxygen-rich blood to meet your heart's needs.
A stress test can show possible signs and symptoms of CHD, such as:
Abnormal changes in your heart rate or blood pressure
Shortness of breath or chest pain
Abnormal changes in your heart rhythm or your heart's electrical activity
As part of some stress tests, pictures are taken of your heart while you exercise and while you rest. These imaging stress tests can show how well blood is flowing in various parts of your heart and/or how well your heart squeezes out blood when it beats.
Angiography
Angiography (an-jee-OG-ra-fee) is a test that uses dye and special x rays to show the insides of your arteries. This test can show whether plaque is blocking your arteries and how severe the blockage is.
A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. A dye that can be seen on x ray is then injected through the catheter into the arteries. By looking at the x-ray picture, your doctor can see the flow of blood through your arteries.
It doesn't appear that their is a specific percentage of blockage, just blockage in general...
