What Is Coronary Microvascular Disease?
Coronary microvascular disease (MVD) is heart disease that affects the walls and inner lining of tiny coronary artery blood vessels that branch off from the larger coronary arteries. Coronary heart disease (CHD), also called coronary artery disease, involves plaque formation that can block blood flow. In coronary MVD, the heart's tiny coronary artery blood vessels do not have plaque, but damage to the inner walls of the blood vessels that can lead to spasms and decrease blood flow to the heart muscle.
Diagnosing coronary MVD has been a challenge for doctors. Standard tests used to diagnose coronary heart disease are not designed to detect coronary MVD, so more research is needed to find the best diagnostic tests and treatments for the disease.
According to the National Heart, Lung, and Blood Institute's Wise study (Women's Ischemia Syndrome Evaluation), research is ongoing to learn more about the role of hormones in heart disease and to find better ways to diagnose coronary MVD.
Other Names for Coronary Microvascular Disease
- Cardiac syndrome X
- Nonobstructive coronary heart disease
The same risk factors that cause atherosclerosis may cause coronary microvascular disease (MVD). Atherosclerosis is a disease in which plaque builds up inside the arteries.
Risk factors for atherosclerosis include:
- Unhealthy blood cholesterol levels
- High blood pressure
- Overweight and obesity
- Unhealthy diet
- Older age
- Family history of heart disease
Women may be at risk for coronary MVD if they have lower than normal estrogen levels at any point in their adult lives. Low estrogen levels before menopause can raise younger women's risk for coronary MVD and can be caused by stress and also a functioning problem with the ovaries.
Women who have high blood pressure before menopause, especially high systolic blood pressure, are at increased risk for coronary MVD. After menopause, women tend to have more of the traditional risk factors for atherosclerosis, which also puts them at higher risk for coronary MVD.
Women who have heart disease are more likely to have a worse outcome, such as a heart attack, if they also have anemia because anemia is thought to slow the growth of cells needed to repair damaged blood vessels.
What Are the Signs and Symptoms of Coronary Microvascular Disease?
Women with coronary MVD often have chest pain called angina, also called microvascular angina usually lasting longer than 10 minutes, and it can last longer than 30 minutes.
Other signs and symptoms of coronary MVD are:
- shortness of breath
- sleep problems
- lack of energy
Diagnosis of Coronary Microvascular Disease
Your healthcare provider will diagnose coronary MVD based on your medical history, a physical exam, and test results. They will also check to see whether you have any risk factors for heart disease. For example, your doctor may measure your weight and height to check for overweight or obesity. He or she also may recommend tests for high cholesterol, metabolic syndrome, and diabetes.
The risk factors for coronary MVD and traditional heart disease often are the same. Thus, your doctor may recommend tests for heart disease, such as:
Coronary MVD symptoms often first occur during routine daily tasks. Because of this, your doctor may ask you to fill out a questionnaire called the Duke Activity Status Index (DASI). The will ask you how well you're able to do daily activities, such as shopping, cooking, and going to work.
The DASI results will help your doctor decide which kind of stress test you should have. The results also give your doctor information about how well blood is flowing through your coronary arteries.
Your doctor also may recommend blood tests, including a test for anemia. Anemia is thought to slow the growth of cells needed to repair damaged blood vessels.
Research is ongoing for better ways to detect and diagnose coronary MVD. Currently, researchers have not agreed on the best way to diagnose the disease.
Treatment of Coronary Microvascular Disease
Relieving pain is one of the main goals of treating coronary microvascular disease (MVD). Treatments also are used to control risk factors and other symptoms.
Treatments may include medicines such as:
- Cholesterol medications to improve cholesterol levels
- Blood pressure medications to lower blood pressure and decrease the heart's workload
- Aspirin to help prevent blood clots or control inflammation
- Nitroglycerin to relax blood vessels, improve blood flow to the heart muscle, and treat chest pain
No specific studies have been done on how to prevent coronary microvascular disease (MVD). Researchers don't yet known how or in what way preventing coronary MVD differs from preventing heart disease. Lifestyle changes and ongoing care can help you lower your risk for heart disease.
- Lifestyle Changes - If lifestyle changes aren't enough, your doctor may prescribe medicines to control your risk factors. Take all of your medicines as your doctor advises.
- Know Your Numbers that Count for a Healthy Heart
- Know your body mass index (BMI)
- Know your family history of heart disease
Duke Activity Status Index (DASI)
The Duke Activity Status Index is a self-administered questionnaire that measures a patient's functional capacity. It can be used to get a rough estimate of a patient's peak oxygen uptake.
- Can you take care of yourself (eating, dressing, bathing or using the toilet)?
- Can you walk indoors, such as around your house?
- Can you walk a block or two on level ground?
- Can you climb a flight of stairs or walk up a hill?
- Can you run a short distance?
- Can you do light work around the house, such as dusting or washing dishes?
- Can you do moderate work around the house, such as vacuuming, sweeping floors or carrying in groceries?
- Can you do heavy work around the house, such as scrubbing floors or lifting and moving heavy furniture?
- Can you do yard work, such as raking leaves, weeding or pushing a power mower?
- Can you have sexual relations?
- Can you participate in moderate recreational activities, such as golf, bowling, dancing, doubles tennis or throwing a baseball or football?
- Can you participate in strenuous sports, such as swimming, singles tennis, football, basketball
VO2peak = (0.43 x DASI) + 9.6
VO2peak = ___________ ml/kg/min ÷ 3.5 ml/kg/min = __________ METS