Coronary Microvascular Disease or Small Vessel Heart Disease: Causes, Symptoms, Diagnosis, Risk Factors, Complications

Coronary microvascular disease or small vessel heart disease is a type of heart diseases in which the small arteries of the heart becomes narrow which causes signs and symptoms of heart problems like chest pain (angina).

Coronary microvascular disease is popularly known as small vessel heart disease. Coronary microvascular disease or small vessel heart disease is usually diagnosed while doctor examines someone for the blockage in the main arteries of the heart in case of heart problems and fails to find any significant issues even on repeated occurrence of symptoms.

The risk of coronary microvascular disease or small vessel heart disease is higher in case of women and those individuals who have high blood pressure or diabetes. Although it is hard to diagnose this disease but once diagnosed, coronary microvascular disease or small vessel heart disease can be fully treated.

• Coronary microvascular disease or small vessel heart disease cause narrowing of arterioles, the smallest coronary arteries of heart.
• Women are more prone to coronary microvascular disease or small vessel heart disease than men.
• Heart disease affects men and women differently.
• Signs and symptoms of coronary microvascular disease or small vessel heart disease are slightly different from that seen in traditional coronary artery disease (CAD). The common symptoms of coronary artery disease are feeling pressure or squeezing in the chest, angina (chest pain), excessive sweating, shortness of breath, pain in shoulder and arms etc.. The women with coronary microvascular disease or small vessel heart disease may show some identical symptoms like sleep problems, lack of energy, fatigue (tiredness), shortness of breath etc. The symptoms of coronary microvascular disease or small vessel heart disease are often noticed during daily activities especially under severe mental stress.
• Coronary microvascular disease is generally caused by the plaque formation in arteries in case of tightening of arteries or in case of any disease or damage to the walls of arteries which stops the oxygen rich blood reaching the muscles of heart.
• Traditional coronary artery disease (CAD) will always lead to blockage in heart which is not always the case with coronary microvascular disease. Thus it falls in the category of non-obstructive coronary artery disease.
• It is normally seen that women with symptoms of heart problems are more likely to be diagnosed with coronary related artery diseases.
• The risk factors for the coronary microvascular disease or small vessel heart disease are almost similar to that of coronary artery disease like diabetes, high blood pressure, insulin resistance, unhealthy cholesterol levels, lack of physical activity, age, smoking, overweight and obesity, and family history of early heart disease.
• It is not easy to detect Coronary microvascular disease straight away. The diagnoses procedure generally begin with a Duke Activity Status Index in which the doctor tries to analyze the heart related problems in your daily routine followed by other pharmacological stress tests and coronary angiogram test to analyze the flow of blood in coronary artery.
• Once diagnosed with coronary microvascular disease or small vessel heart disease, the patients must ensure that it does not get worse making necessary changes in lifestyle and taking proper medicines, and regular medical care.

The larger arteries carry most of the oxygenated blood from heart to different parts of the body and small vessels assist the arteries by when you are active and then contract back when you relax.

In some individuals, the small arteries may get narrow and may not be able to expand when you are in active mode leading to insufficient supply of oxygenated blood to the body. This situation in which the small arteries cannot expand properly is referred as endothelial dysfunction. This can affect your small vessels even worse by making them even narrower during emotional stress or active mode causing symptoms similar to heart attack or angina.

Women have higher possibilities of encountering with coronary microvascular disease or small vessel heart disease as factors like smoking, high blood pressure, diabetes can cause more harm in case of women. Also there are some things like pregnancy, menopause, and contraceptive pills, postmenopausal estrogens which are associated with particularly women and degrade their body.

Theories on why the disease may differ in women include the following:

• Low levels of estrogen can cause coronary microvascular disease or small vessel heart disease in women. Estrogen is vital hormone which helps in processing nitric oxide and proper functioning of arteries. Thus lack of estrogen causes problems with endothelium.
• More inflammation (an overreaction by the human immune system). Immune system may respond with high inflammation to cut down the levels of cholesterol in the bloodstream.
• Higher incidence of anemia may reason to coronary microvascular disease or small vessel heart disease. Women are more at risk of anemia which hampers the cells involved in the repair of damaged blood vessels.
• Lower levels of hemoglobin (a protein in red blood cells that carries oxygen) can cause coronary microvascular disease or small vessel heart disease. Lack of hemoglobin means less supply of oxygen to the heart muscle and reduction in nitric oxide levels.
• Lower HDL (good cholesterol) levels. Individuals with low HDL are more at the risk of coronary heart disease which is often seen in women.

The signs and symptoms of coronary microvascular disease or small vessel heart disease are as follows:

• Trouble sleeping.
• Pain in the chest, squeezing or discomfort.
• Shoulder, neck, upper back or abdominal discomfort.
• Loss of energy.
• Severe fatigue.
• Chest pain associated with discomfort in your left arm or jaw.
• Shortness of breath.
• Chest pain that becomes worse with everyday activities and at times of emotional stress is a symptom of coronary microvascular disease or small vessel heart disease.

You may develop coronary microvascular disease or small vessel heart disease as a follow up of treatment of coronary artery disease (CAD) with angioplasty and stents and then the signs and symptoms persist even after treatment.

Usually if an individual faces problems like nausea, shortness of breath, dizziness, sweating, or extension of pain from chest to one or both of your arms or your neck along with symptoms of heart pain, he/she must take immediate medical assistance.

Symptoms like abdominal pain and fatigue are common and may or may not be associated with coronary microvascular disease or small vessel heart disease. However if same is accompanied by chest pain, you must refer to doctor. The doctor tries to diagnose this problem by asking one or more of the below questions:

• Do your symptoms get worse when you are active?
• When did you first start noticing the signs and symptoms of coronary microvascular disease or small vessel heart disease?
• Do you have a family history of heart disease?
• Have your signs been occasional or constant?
• Have you ever been diagnosed with high blood pressure, diabetes or high cholesterol? Do you have any other medical conditions?
• How intense are your signs and symptoms? Has the severity of your symptoms worsened?

The following are the risk factors associated with coronary microvascular disease or small vessel heart disease:

• Tobacco usage
• Being female
• Increasing age, older than 55 in women and older than 45 in men.
• High blood pressure
• Inactive lifestyle
• An estrogen deficiency, in women.
• High cholesterol
• Insulin resistance
• Diabetes
• Obesity (body mass index which is greater than 30.)
• Polycystic ovarian syndrome
• Unhealthy diet

It is still a mystery as to why factors like inactive lifestyle and obesity leads to coronary microvascular disease or small vessel heart disease in some individuals against large vessel coronary artery disease.

Problems with small vessels directly affect the supply of oxygen by degrading the pumping action of blood. Thus coronary microvascular disease or small vessel heart disease must not be ignored as it may cause serious complications like:

• Heart failure is a possible complication in coronary microvascular disease or small vessel heart disease.
• Heart attack, sudden cardiac death is also a complexity in coronary microvascular disease.
• Coronary artery spasm

The signs and the symptoms of the large vessel coronary artery disease and small vessel disease are almost similar. Thus the doctor first checks for the large vessel coronary artery disease and if that is not found, he/she goes for the diagnoses of coronary microvascular disease or small vessel heart disease with some additional set of tests.

The general test procedure for coronary microvascular disease or small vessel heart disease involves a physical test and some common set of questions to know about the family history of any type of heart disease. Also you will be checked for the level of cholesterol in blood as it can cause clogging and symptoms of chest pain.

The set of tests for coronary microvascular disease or small vessel heart disease are similar to tests for other heart diseases like:

• Stress test with imaging for coronary microvascular disease or small vessel heart disease. This test involves analyzing your heart when it is under stress like it is the case when you are exercising. Thus the doctor would ask the patient to take up an exercise like walking on a treadmill or bike to put the heart in stress and then create the digital images of the heart with the help of ultrasound images (echocardiogram) or nuclear imaging scans which are then used to check for the proper flow of blood in heart through vessels.
• Positron emission tomography or PET Test for coronary microvascular disease or small vessel heart disease. It is an expensive test and thus it is not always used in diagnoses. Through PET, the doctor analyzes the flow of blood from heart to other part of the body by injecting a radioactive dye in the blood stream and then analyzing the images of the scan on computer taken while you are made to lie in a doughnut-shaped machine.
• Magnetic resonance imaging (MRI) for coronary microvascular disease or small vessel heart disease. MRI is an advanced test in which digital images of the heart are created with a special tube like machine which radiates magnetic field. These radiations cause some of the atomic particles in cell to align which help in creating different images of different tissues. By looking at the images obtained by MRI, the doctor can identify any blockage in the main arteries.
• Endothelial function test for coronary microvascular disease or small vessel heart disease. Endothelium is a type of covering that exists over the blood vessels and thus it can be examined to detect the problems with vessels. It is a non-invasive test in which blood pressure cuff and finger probes are used. It is not a definite test for small vessel coronary artery disease but can be reveal any problems in heart.
• Coronary angiogram for testing coronary microvascular disease or small vessel heart disease. In this test, a long thin tube is used to inject special dye into the artery that run through groin to heart to analyze any narrowing or blockage of main arteries. X-rays are used to create images and videos of the heart in this technique.

If the above tests does not show any signs of blockage in main arteries, the patients is referred for the other additional tests to detect any blockages in the smaller arteries of your heart:

Endothelial dysfunction test for diagnosing coronary microvascular disease or small vessel heart disease is a special type of medication is inserted directly into the small vessels through a catheter. It is a special liquid that opens up the small vessels causing the blood to rush through. By analyzing the flow of blood, any blockage can be detected in small vessels. Although it is an invasive type of test but very definitive in diagnosing the small vessel disease.

Also Read:

• Treatment for Coronary Microvascular Disease or Small Vessel Heart Disease & Its Prevention, Coping, Exercises