Small vessel disease is a condition in which the walls of the small arteries in the heart are damaged. The condition causes signs and symptoms of heart disease, such as chest pain (angina).
Small vessel disease is sometimes called coronary microvascular disease or small vessel heart disease. It's often diagnosed after a doctor finds little or no narrowing in the main arteries of your heart, despite your having symptoms that suggest heart disease.
Small vessel disease is more common in women and in people who have diabetes or high blood pressure. The condition is treatable but can be difficult to detect.
Small vessel disease signs and symptoms include:
- Chest pain, squeezing or discomfort (angina), which may worsen during daily activities and times of stress
- Discomfort in your left arm, jaw, neck, back or abdomen associated with chest pain
- Shortness of breath
- Tiredness and lack of energy
If you've been treated for coronary artery disease with angioplasty and stents and your signs and symptoms haven't gone away, you might also have small vessel disease.
When to see a doctor
If you're having chest pain and other signs and symptoms — such as shortness of breath, sweating, nausea, dizziness, or pain that radiates beyond your chest to one or both of your arms or to your neck — seek emergency medical care.
It might be hard to tell if your symptoms are due to small vessel disease, especially if you don't have chest pain. If you do have chest pain, see your doctor to find out the cause.
Experts suspect that the causes of small vessel disease are the same as the causes for disease of the larger vessels of the heart, such as high blood pressure, high cholesterol, obesity and diabetes.
The large vessels in your heart can become narrowed or blocked through a condition in which fatty deposits build up in the arteries (atherosclerosis). In small vessel disease, damage to the small vessels affects their ability to expand (endothelial dysfunction). As a result, your heart doesn't get enough oxygen-rich blood.
Small vessel disease is more common in women. Risk factors include:
- Tobacco use
- Unhealthy cholesterol levels
- High blood pressure
- Obesity (body mass index of 30 or higher)
- Unhealthy diet
- Inactive lifestyle
- Insulin resistance
- Estrogen deficiency, in women
- Polycystic ovarian syndrome
- Increasing age, older than 45 in men and older than 55 in women
- Chronic inflammation
It's not clear why the same risk factors, such as obesity or an inactive lifestyle, cause some people to develop small vessel disease instead of large vessel coronary artery disease.
Because small vessel disease can make it harder for the heart to pump blood to the rest of the body, the condition, if untreated, can cause serious problems, such as:
- Coronary artery spasm
- Heart attack
- Congestive heart failure
Because large vessel coronary artery disease and small vessel disease have the same signs and symptoms, it's likely your doctor will check the main arteries in your heart first. If no problems are found, then your doctor might test for small vessel disease.
To diagnose small vessel disease, your doctor will also ask you about your medical history and family history of heart disease. During your exam your doctor will likely check for high cholesterol and diabetes.
The tests for small vessel disease are similar to those for other types of heart disease and include:
Stress test with imaging. You'll either exercise on a treadmill or a bike or take a medication that raises your heart rate to mimic the effect of exercise.
Images will be taken of your heart using ultrasound images (echocardiogram) or with nuclear imaging scans to assess the blood flow to your heart muscle.
- Coronary angiogram. This test helps doctors determine if the main arteries to your heart are blocked. A liquid dye is injected into the arteries of your heart through a catheter — a long, thin tube that's fed through an artery, usually in your groin, to arteries in your heart. As the dye fills your arteries, they become visible on X-ray and video.
- Positron emission tomography (PET). This test, which uses a radioactive dye and medication, can show your heart's blood flow to other parts of your body. After the dye is injected, you lie in a doughnut-shaped machine to have images taken of your heart.
- CT scan or CT angiography (CTA) scan. A CT scan combines a series of X-rays taken from different angles with computer processing to create detailed images. A CTA scan uses a contrast dye injected through a line in your arm or hand to assess your blood vessels.
- MRI. In a cardiac MRI, you lie on a table inside a long tubelike machine that produces a magnetic field. MRI produces images of your heart that enables your doctor to see blockages.
If your doctor can't find blockages in your main arteries based on these tests, you might have an additional test to check for blockages in the smaller arteries of your heart:
Endothelial dysfunction test. The endothelium is a layer of cells that line all of your blood vessels. When the endothelium isn't functioning well, the blood vessels can't expand properly.
To test endothelial function, a wire is threaded through a catheter inserted in one of your coronary arteries and a medication is injected into the artery that causes the small vessels in your heart to open. Then the blood flow through those vessels is measured.
This invasive test is the surest way to detect small vessel disease. Researchers are looking at noninvasive methods of endothelial function.
The treatment for small vessel disease involves medications to control the narrowing of your small blood vessels that could lead to a heart attack and to relieve pain. Your doctor could prescribe:
- Nitroglycerin. Nitroglycerin tablets, sprays and patches can ease chest pain by relaxing your coronary arteries and improving blood flow.
- Beta blockers. These drugs, such as propranolol (Inderal, Innopran XL, others) and bisoprolol (Zebeta), slow your heart rate and decrease your blood pressure.
- Calcium channel blockers. Drugs such as verapamil (Verelan, Calan, others) and diltiazem (Cardizem, Diltzac, others) relax the muscles around your coronary arteries and cause the vessels to open, increasing blood flow to your heart. They also control high blood pressure.
- Statins. Medications such as atorvastatin (Lipitor) and simvastatin (Zocor) help lower cholesterol, which contributes to the narrowing of your arteries. Statins also help relax the blood vessels of your heart and treat blood vessel damage.
- Angiotensin-converting enzyme (ACE) inhibitors. Medications such as benazepril (Lotensin) and lisinopril (Prinivil, Zestril) help open your blood vessels and lower your blood pressure.
- Angiotensin II receptor blockers (ARBs). Medications such as azilsartan (Edarbi) and losartan (Cozaar) relax your blood vessels, which lowers your blood pressure and makes it easier for your heart to pump blood.
- Ranolazine (Ranexa). This medication eases chest pain by altering sodium and calcium levels.
- Aspirin. Aspirin can limit inflammation and prevent blood clots.
If you're diagnosed with small vessel disease, you'll need to see your doctor regularly for checkups. Your doctor will determine how often you'll need to be examined, depending on the severity of your condition.
A dietary supplement that may be helpful for people with small vessel disease is L-arginine. This amino acid that's normally used by the body to help metabolize protein may help treat symptoms of small vessel disease by relaxing your blood vessels. This therapy shouldn't be used in anyone who's already had a heart attack.
Talk to your doctor before adding a supplement to your treatment to ensure that it won't interfere with medications you take.
If you've had chest pains or other symptoms of heart disease, your primary care provider will likely refer you to a doctor trained in treating disorders of the heart and circulatory system (cardiologist).
Here's some information to help you get ready for your appointment.
What you can do
When you make the appointment, ask if there's anything you need to do in advance, such as fasting before a specific test. Make a list of:
- Your symptoms, including any that seem unrelated to the reason for your appointment
- Key personal information, including major stresses; recent life changes; your and your family's medical history, especially history of heart disease, high blood pressure, diabetes and high cholesterol
- All medications, vitamins or other supplements you take, including the doses
- Questions to ask your doctor
Take a family member or friend along, if possible, to help you remember the information you're given.
For small vessel disease, basic questions to ask your doctor include:
- What's likely causing my symptoms?
- Other than the most likely cause, what are other possible causes for my symptoms?
- What tests do I need?
- Is my condition likely temporary or chronic?
- What's the best course of action?
- What are the alternatives to the primary approach you're suggesting?
- I have these other health conditions. How can I best manage them together?
- Are there restrictions I need to follow?
- Should I see a specialist?
- Are there brochures or other printed material I can have? What websites do you recommend?
Don't hesitate to ask other questions.
What to expect from your doctor
Your doctor is likely to ask you questions, such as:
- When did your symptoms begin?
- Have your symptoms been continuous or occasional?
- How severe are your symptoms? Have your symptoms worsened?
- Do your symptoms worsen when you're active?
- Does anything make your symptoms better?
There are no studies about preventing small vessel disease, but it seems that controlling the disease's major risk factors — high blood pressure, high cholesterol and obesity — can help.
Things you can do that might reduce your risk include:
- Don't smoke or use other tobacco products. If you smoke, stop. Quitting other forms of tobacco use can also be helpful. Talk to your doctor if you have trouble quitting.
- Eat a heart-healthy diet. Eat a heart-healthy diet that includes whole grains, lean meat, low-fat dairy, and fruits and vegetables. Limit salt, sugar, alcohol, and saturated fat and trans fats.
Exercise regularly. Regular exercise helps improve heart muscle function and keeps blood flowing through your arteries. It can also prevent a heart attack by helping you 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 your health.
- Check your cholesterol. Have your blood cholesterol levels checked regularly through a blood test. If your "bad" cholesterol levels are high, your doctor can prescribe changes to your diet and medications to help lower the numbers and protect your cardiovascular health.
- Control your blood pressure. Ask your doctor how frequently you should have your blood pressure checked. He or she might recommend more-frequent checks if you have high blood pressure or a history of heart disease.
- Maintain a healthy weight. Excess weight strains your heart and can contribute to high cholesterol, high blood pressure and diabetes.
- Manage stress. Rethink workaholic habits and find healthy ways to minimize or deal with stressful events in your life. Yoga, meditation and listening to music can help reduce stress.
- Control blood sugar levels if you have diabetes. Keep your blood sugar at appropriate levels to help reduce the risk of complications. Work with your doctor to establish blood sugar goals that are right for you.