|
Coronary microvascular disease is tough to diagnose. If you are experiencing symptoms that concern you, don't ignore them. You need to continue a dialog with your doctor until you're both satisfied.
If your doctor suspects you are at risk for heart disease, there are a number of traditional diagnostic tests used to look for blockages that affect blood flow in the large coronary arteries (coronary artery disease or CAD). However, standard tests for CAD, such as electrocardiograms, exercise stress tests, echocardiograms and angiograms don't always detect coronary microvascular disease (MVD), a disease where the smallest coronary arteries are affected. For more information about tests to diagnose heart disease, see the Second Opinion episode on Cardiac Breakthroughs.
As more is learned about coronary MVD, new protocols and tests are emerging.
Self-Reported Physical Fitness Scores
Since symptoms of coronary MVD often first appear during routine daily tasks, a questionnaire called the Duke Activity Status Index (DASI) that asks about an individual's ability to perform certain daily tasks can prove useful. It yields information about how well blood is flowing through coronary arteries and also helps doctors select appropriate next steps.
Duke Activity Status Index
|
Activity |
Points |
|
Can you take care of yourself (eating, dressing, bathing, etc.)? |
0.8 |
|
Can you walk around your house? |
0.5 |
|
Can you walk a block or two on level ground? |
0.8 |
|
Can you climb a flight of stairs or walk up a hill? |
1.6 |
|
Can you run a short distance? |
2.3 |
|
Can you do light work around the house (washing dishes, etc.)? |
0.8 |
|
Can you do moderate work around the house (sweeping, carrying groceries, etc.)? |
1.0 |
|
Can you do heavy work around the house (scrubbing floors, moving heavy furniture, etc.)? |
2.3 |
|
Can you do yard work (raking leaves, pushing a mower, etc.)? |
1.3 |
|
Can you have sexual relations? |
1.5 |
|
Can you participate in moderate recreational activities (golf, dancing, etc.)? |
1.7 |
|
Can you participate in strenuous sports (swimming, singles tennis, skiing, etc.)? |
2.1 |
|
Circle the points for a question only if you can answer "Yes, with no difficulty." Add up the circled points. The lower the score, the greater the risk. Total scores of 4.7 or below are considered higher risk. |
Stress Tests
Stress tests are performed to determine whether there's enough blood flow to the heart during physical activity. They involve performing simple exercise, usually with a treadmill or a stationary bike. Sometimes pharmacological agents are used to simulate the heart's reactions to exercise. Standard stress tests tend not to be as reliable in women as in men, but using imaging such as echocardiograms or nuclear scans in conjunction with an exercise stress tests improves their accuracy.
• Adensosine Coronary Flow Reserve and Acetylcholine Endothelial Function Test with Cardiac Magnetic Resonance Imaging (MRI)
This is a pharmacological stress test. During the two-step test, the drug adenosine, which causes the small vessels of the heart to dilate, is injected into one of the coronary arteries and the amount of blood flow is measured. Next, the drug acetylcholine, which causes dilation in the large arteries, is injected and the amount of blood flow is again measured. The superior resolution of magnetic resonance imaging is used to get images of the beating heart and to look at its structure and function. MRIs can show poor blood supply to the innermost areas of the heart and can detect changes in the small coronary blood vessels. If either test shows decreased blood flow to the heart muscle, a diagnosis of microvascular disease can be made.
• Dipyridamole Positron Emission Tomography (PET)
This cardiac PET scan also shows how much blood flow the heart receives at rest and under stress. During the first stage, fluorodeoxyglucose (FDG) is administered while the patient is at rest. The images that are produced from this first PET scan are checked with a second PET scan after the patient is administered dipyridamole, a drug that produces an effect in the body similar to the effects of strenuous exercise.
Doppler Wire Coronary Angiogram
The most definitive test for microvascular disease is a special type of coronary angiogram used to measure coronary artery flow reserve or coronary reactivity. It involves threading an ultrathin wire with blood-flow sensors at the tip deep into a coronary artery (called cardiac catheterization). Blood flow in the artery is then measured before and after injections of one or more medications to cause the microvessels to dilate. The smaller the change in pressure and flow, the stiffer the vessels. This test is done only at a small number of cardiac centers in the country. Cardiac catheterization procedures are invasive and expensive, but the risks of doing them have to be weighed against the risks of not being accurately diagnosed.
A great deal remains to be learned about coronary MVD, especially in women. In the meantime, there are some basic strategies that you can use to get an accurate diagnosis and the best possible medical care. Listen to your body and believe in your instincts. If you feel strongly that something is wrong but your doctor can't find a problem, get a second opinion. Find a specialist who is familiar with coronary MVD. Ask questions. If you don't fully understand the answers, ask more questions until you do. There's nothing more important than your health. By balancing assertiveness with respect for your physicians, you can get the information you need.
Learn more about Coronary Microvascular Disease:
Key Point 1: When it comes to heart disease, not only are the symptoms sometimes different for men and women – but the disease itself may be different.
Key Point 3: If you've been diagnosed with coronary microvascular disease, getting adequate blood flow to your heart is critical. Lifestyle changes are the most effective treatment.
|
