Special Focus: Which Tests Do I Need?
Many women are unaware of the difference between the tests available to detect and diagnose heart disease.  Some tests are especially important in women based on a variety of factors. 

Blood Tests
Various blood tests can be done to assess the risk of heart disease. The most valuable blood test in this regard is called a lipid profile. This blood test is done after 12-14 hrs of fasting. The test involves measurement of total cholesterol, LDL (bad) cholesterol, HDL (good) cholesterol and triglycerides. The National Adult Cholesterol Education Panel has recommended that the first measurement be done at age 20 years. High cholesterol levels, in particular high LDL levels, has been shown to increase risk of coronary artery disease. Low HDL levels also contributes to risk of coronary artery disease. Low HDL along with high triglyceride levels can be an especially important target of treatment in women to reduce risk of coronary artery disease.

A thyroid profile should be done in patients with high cholesterol level before starting treatment, as low levels of thyroid hormone can lead to high cholesterol.

CRP
C-Reactive Protein is a marker of inflammation and is elevated in diseases associated with chronic inflammation, like rheumatoid arthritis and chronic inflammatory bowel disease. But mildly increased levels of this marker have been found to be associated with increased incidence of cardiac events and stroke. It is felt that increased inflammation in atherosclerotic plaque is responsible for rupture of plaque leading to heart attack. The Women's Heart Study found CRP to be a potent predictor of cardiac risk. CRP is also elevated in women with metabolic syndrome and may be partly responsible for increased risk of heart disease in these women.

Other blood tests like homocysteine levels or Lpa levels are other emerging risk factors that should be measured selectively to assess risk and guide treatment in younger patients with premature coronary artery disease.

Stress Testing
Stress testing is done to diagnose underlying coronary artery disease. Your heart is stressed either by walking on a treadmill or riding a stationary bike. An electrocardiogram (EKG) is done at rest and during various stages of exercise. Total duration of exercise, along with heart rate and blood pressure response to exercise are measured. All these factors can be utilized to assess the presence and severity of coronary artery disease.

A standard exercise EKG test can be less accurate in women due to fluctuation in hormone levels during various periods in menstrual cycle, therefore echo or nuclear imaging is usually added to improve the accuracy of the stress test.

Pharmacological stress tests use a drug such as adenosine to reproduce the effects of exercise on heart. This is a safe alternate for many women who cannot perform adequate exercise due to deconditioning, arthritis or lung problems.

Nuclear Imaging
A nuclear scan, also called myocardial perfusion imaging or MPI, involves injecting a liquid called a tracer into your bloodstream, which then flows to your heart. While you lie on an exam table, a special camera moves over your chest and takes "pictures" of your heart. MPI is combined with exercise or pharmacologic stress tests to measure the blood flow to the heart. If there is a significant blockage of a coronary artery, the heart muscle may not get enough blood supply. The resulting images can show damage to the heart muscle and blood flow problems. Since this test exposes you to a very small amount of radiation, tell your healthcare provider if you think you might be pregnant.

Echocardiogram
An echocardiogram is an ultrasound picture of your heart. An ultrasound transducer is used to bounce sound waves off the structures of the heart to produce a motion picture of your heart. This test is noninvasive and gives detailed information about the size of various heart chambers, a measure of pumping action of the heart (ejection fraction), and helps assess the function of heart valves. This test does not show the coronary arteries in any detail, but instead the eextent of heart heart damage. By measuring the blood flow across the valve with the Doppler ultrasound, we can measure some pressures inside the heart. This test is also very useful in diagnosing some forms of congenital heart disease.

Calcium Scoring
An ultra-fast CT scan can non-invasively detect and measure calcified atherosclerotic plaque in the coronary arteries. In middle aged men and women, a higher quantity of coronary artery calcium is associated with increased risk of future heart attacks. When analyzed with traditional risk factors for coronary artery disease, the presence and extent of coronary calcium can help plan for the prevention and treatment of coronary artery disease.

Angiography (cardiac catheterization)
This test involves insertion of a long thin tube (catheter) from the leg or arm artery. This catheter is then advanced under x-ray control to the heart. The catheter is then selectively engaged in the coronary artery (blood vessel taking oxygen to the heart muscle). Iodine dye is then injected through this catheter and digital images are taken in various views to assess the extent and severity of blockage in these arteries. This is the most definitive test available at this time to diagnose blockages in coronary arteries caused by atherosclerotic plaque. As this test is invasive and carries a small risk, it is recommended only in patients with definitive symptoms of heart disease or an abnormal stress test. This test is also done in patients who require heart valve surgery prior to proceeding with this surgery.

For more information on any of these tests, please call the Women's Heart Center at 630/851-6440.