Coronary micro-vascular disease, its symptoms and prevention
Coronary micro-vascular disease is a heart disease that involves the walls of the tiny coronary blood vessels, branching off from the main coronary arteries. In this disease, the tiny blood vessels don’t have plaque build-up but there is damage to the inner walls of the blood vessels, which can lead to spasms decreasing blood flow to the heart muscle.
Coronary micro-vascular disease can be present in both men and women but it is more common in women. Nearly 60 percent of women who have chest pain or suspected reduced blood flow to the heart do not have blockages in the main coronary arteries. This makes their heart disease more challenging to diagnose for the treating heart specialist. Women with symptoms of heart disease but no blockages in the major coronary arteries have a higher risk for depression and a lower quality of life. Coronary micro-vascular disease may contribute to later development of coronary artery disease.
It has been found that the tiny coronary blood vessels feeding the heart muscle don’t dilate properly and cannot accommodate increased blood flow. The condition, called vascular dysfunction, occurs both in women with clear arteries and in those with coronary artery narrowing. Vascular dysfunction causes stiffening of the network of smaller vessels that also nourish the heart, resulting in a decrease of blood flow to the heart muscle. The condition has been dubbed as coronary vascular dysfunction.
Postmenopausal women, who do not use hormone replacement therapy, are more likely than hormone users to have coronary micro-vascular dysfunction. However, traditional risk factors for atherosclerosis are not associated with disordered coronary microcirculation in women with chest pain in the absence of obstructive coronary artery disease. Coronary micro-vascular disease is also referred to as cardiac syndrome X.
Cardiac syndrome X, which is thought to be caused by micro-vascular dysfunction, can be treated by improving micro-vascular vasomotor tone with oral L-arginine, a precursor to vascular nitric oxide, and estrogen. The micro-vascular physiology in women may be regulated by myocytes present in the media of the coronary micro-vessels. This is based on the finding that the longer duration of menopausal estrogen loss is associated with worse coronary blood flow velocity and that postmenopausal women, who recently used estrogen, were significantly more likely than estrogen nonusers to have normal micro-vascular function.
Symptoms of coronary micro-vascular disease – The symptoms are normally noticed during daily activities such as shopping, cooking, cleaning or going to work and during times of stress. The main symptom is angina but other symptoms may be noticed in its absence as mentioned below.
- Angina - Many women have angina, which is chest pain or discomfort that occurs, when the heart muscle doesn't get enough oxygen-rich blood. Angina may feel like pressure or squeezing in the chest. One also may feel it in one’s shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion. However, the angina that occurs in coronary micro-vascular disease may differ from the typical angina that occurs in coronary heart disease. In coronary micro-vascular disease, the chest pain usually lasts longer than 10 minutes, and it may last longer than 30 minutes. Typical angina is more common in women older than 65.
- Shortness of breath
- Sleep difficulties
- Lack of energy
Diagnosis – The following diagnostic tests can be employed for its diagnosis.
Stress test - This test shows how blood flows through the heart during physical stress, such as exercise. A stress test may still show abnormal blood flow even in the absence of plaque build-up in the coronary arteries as revealed by coronary angiography. This may be a sign of coronary micro-vascular disease.
Cardiac MRI (magnetic resonance imaging) stress test – It is employed in persons for evaluation, who have chest pains. Images of the heart are created, which the doctor will look at to determine if the main arteries in the heart are blocked.
Coronary angiography - Coronary angiography can show plaque buildup in the large coronary arteries. This test often is done during a heart attack to help find blockages in the coronary arteries.
Positron emission tomography (PET) - This test can show the heart's blood flow to other parts of the body. PET scans may help diagnose small vessel disease, but the test is expensive and not widely used.
Endothelial dysfunction test - In this test, a wire will be threaded through a catheter inserted in one of the coronary arteries. Then a medication is injected into the artery that causes the small vessels in the heart to open and let blood rush through. And then the blood flow through those vessels is measured. This test is invasive; it's a good way to detect small vessel disease.
Prevention of coronary micro-vascular disease –
No specific studies have been conducted so far to show how to prevent coronary micro-vascular disease; nonetheless, it can be prevented by adopting the preventive measures of lifestyle changes employed for the coronary heart disease.
Manage high blood pressure - The condition itself usually has no signs or symptoms. One can have it for years without knowing it. Keeping the blood pressure within its normal rage will prevent the development of coronary heart disease. So, it is important for a person having hypertension to adopt all the measures to keep it under good control including pharmaceutical management.
Maintain a healthy weight - Being overweight or obese puts one at risk for many health problems. The more body fat one has and the more one weighs, the more likely one is to develop coronary heart disease. Reaching and staying at a healthy weight is a long-term challenge for people, who are overweight or obese. Simultaneously, it also is an opportunity to lower risk for other serious health problems. With the right treatment and motivation, it's possible to lose weight and lower the long-term disease risk.
Don’t smoke - If an individual smokes, the most important thing he or she can do to improve your heart's health is to stop. Quitting other forms of tobacco use can also be helpful.
Eat a heart healthy diet - A heart-healthy diet includes plenty of whole grains, lean meat, low-fat dairy, and fruits and vegetables. Also, one should watch the intake of salt and fat. Eating too much salt and saturated or trans fats may increase blood pressure and cholesterol, which predispose an individual to the development of coronary heart disease.
Exercise regularly - Regular exercise helps improve heart muscle function. It can also prevent coronary heart disease by helping to achieve and maintain a healthy weight and control diabetes, elevated cholesterol and high blood pressure. Exercise doesn't have to be vigorous. Walking 30 minutes a day five days a week can improve one’s health.
Check cholesterol - If the bad cholesterol levels are undesirably high, you can consult your doctor to prescribe changes to your diet and medications to help lower the numbers and protect your cardiovascular health.
Manage diabetes - If you are diabetic, keeping your blood sugar at appropriate levels can help reduce the risk of complications that includes coronary heart disease. Consult your doctor to help you in managing your diabetes.
Manage stress – Reduce stress in your day to day activities in order to reduce the risk of coronary artery disease. Find healthy ways to minimize or deal with stressful events in your life. Change the workaholic habits.
Manage polycystic ovary syndrome – Women with polycystic ovary syndrome should manage it effectively in order to reduce the risk of coronary micro-vascular disease.
Summary – Coronary micro-vascular disease is found in both sexes but it is more common in women amounting to about 60% of all such cases. Since there is no evidence of blockages in the main coronary arteries, it throws a challenge to the physician to diagnose the disease if women complain of angina, shortness of breath, sleep difficulties and lack of energy. Basically, the vascular dysfunction of the smaller vessels of the main coronary arteries has been held responsible to cause the disease because it produces stiffening of these smaller vessels, which results in a decreased blood flow to the heart muscle.
No specific studies have been conducted to find out the specific preventive measures against the disease. But, nevertheless, the disease can be prevented by adopting the preventive measures for the coronary heart disease, which include eating a healthy diet, maintaining a healthy weight, quitting smoking and exercising regularly. If a person has high blood pressure, diabetes or high blood cholesterol, it should be managed appropriately. Women with polycystic ovary syndrome should use extra caution in the management of their disease. Notwithstanding all these precautions, a person should attempt to reduce the ubiquitously present stress to a minimum in his or her life.