How is atherosclerosis diagnosed?
Atherosclerosis is usually diagnosed after other complications have arisen and another conditions has been diagnosed, such as coronary artery disease. To determine the cause of your symptoms, your doctor will review your symptoms, review your medical and family medical history, and complete a physical exam.
Often atherosclerosis is not diagnosed until you have complications. However, before you experience complications, your health care professional may be able to hear a blowing sound when holding a stethoscope over a damaged artery. Also, you may have a decreased pulse in the affected area. Sometimes, atherosclerosis causes the blood pressure in each of your arms to be significantly different, another symptom your health care professional can easily check.
Coronary angiography (or arteriography). This test is used to explore the coronary arteries. You will be injected with a dye via a fine tube, or catheter, that is put into an artery of an arm or leg and passed through the aorta into the arteries of your heart. The heart and blood vessels are then filmed while the heart pumps. The picture that is seen, called an angiogram or arteriogram, will show blockage caused by atherosclerosis, as well as other problems. This is the most accurate way to assess the presence and severity of coronary disease. You may be injected with a fluid that blocks x-rays, called a "contrast medium" or "dye," that causes specific tissues to be more visible. The injection may sting and cause you to experience a metallic taste, a warm or cool sensation at the injection site and in some cases, hives. Many of these dyes are iodine-based, so you need to tell your health care professional if you are allergic to iodine, because allergic reactions can sometimes be dangerous. Steroids and Benadryl can be given ahead of time to prevent an allergic reaction. If your health care professional decides that you need to have an angiography, you may have to fast four to six hours before the test because of sedative medications given during the test.
A CT scan. A computerized tomography scan, or CT scan, sends x-rays through your body at various angles, and these rays are read by a scanner. These are later compiled and analyzed by a computer. You will lie on a narrow table that slides into a tube-shaped scanner. Your health care professional will move the table approximately 1/4 to 1/2 inch after each scan to achieve a cross-sectioned image of the area. Each scan takes only a few seconds, although the entire test may take an hour. You will need to remain very still during the test. A very fast CT scan called an Electron Beam CT (EBCT) can directly visualize the heart arteries and measure the amount of calcium in the arteries. Since the amount of calcium in the artery directly correlates with the amount of atherosclerotic plaque in the arteries, this can be a non-invasive way for a health care professional to determine if a patient without symptoms has evidence of atherosclerotic plaque in order to treat him or her more aggressively. However, most insurance companies do not cover the cost of this test; and this machine is not found at all medical centers. CT technology is improving and health care professionals are now able to do CT angiography. This involves injecting dye into a peripheral vein via an IV in the arm and taking pictures of the coronary arteries with CT scan. This is comparable to the standard coronary angiogram described above which involves injecting dye directly into the arteries of the heart and which is a much more invasive.
For many women with angina, the ECG at rest is normal. This is not surprising because the symptoms of angina occur during stress. Therefore, the functioning of the heart may be tested under stress, typically exercise. In the simplest stress test, the ECG is taken before, during and after exercise to look for stress-related abnormalities. Blood pressure is also measured during the stress test and symptoms are noted. Other stress tests in addition to the ECG use radionucleotide markers such as thallium, or ultrasound (echocardiography), to take pictures of the heart before and after the stress to look for changes in the heart that might suggest blockages. Usually the stress test involves running on a treadmill, but in patients who are unable to use the treadmill, the heart can be stressed using medications such as dobutamine or adenosine.
However, the contrast coronary angiography, CT scan and ECG are not standard tests for atherosclerosis. The nuclear or echo stress tests may suggest blockages, but this currently can only be confirmed using contrast coronary angiography.
Exercise stress test. This test shows how well the heart functions with increased physical activity. And EKG and blood pressure are taken before, during and after the workout.