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How healthy are your coronary arteries? If you eat healthy foods, get physical activity every day and don't smoke, you're well on your way to preventing symptoms of coronary artery disease — a leading type of heart disease.

The coronary arteries supply your heart with blood, oxygen and nutrients. When blood flow through the coronary arteries becomes obstructed, it's known as coronary artery disease.

Coronary artery disease is caused by the gradual buildup of fatty deposits in your coronary arteries (atherosclerosis). As the deposits slowly narrow your coronary arteries, your heart receives less blood. Eventually, diminished blood flow may cause chest pain (angina), shortness of breath or other symptoms. A complete blockage can cause a heart attack.

Since coronary artery disease often develops over decades, it can go virtually unnoticed until it produces a heart attack. But there's plenty you can do to prevent coronary artery disease. Start by committing to a healthy lifestyle.

If your coronary arteries become narrowed, they can't supply enough oxygenated blood to your heart — especially when it's beating hard, such as during physical activity. At first, the restricted blood flow may not cause any symptoms. As the fatty deposits continue to accumulate in your coronary arteries, however, you may have:

• Chest pain. You may feel pressure or tightness in your chest, as if someone were standing on your chest. The pain is usually triggered by physical or emotional stress. It typically goes away within minutes after stopping the stressful activity. Atypical chest pain — more common in women — may be fleeting or sharp and noticed in the abdomen, back or arm.
• Shortness of breath. If your heart can't pump enough blood to meet your body's needs, you may develop symptoms of heart failure — shortness of breath, extreme fatigue with exertion, and swelling in your feet and ankles.
• Heart attack. If a coronary artery becomes completely blocked, you may have a heart attack. The classic symptoms of a heart attack include crushing pain in your chest, pain in your shoulder or arm, and shortness of breath. Women are somewhat more likely than men to experience other warning signs of a heart attack, including nausea and back or jaw pain. Sometimes a heart attack occurs without any apparent signs or symptoms.

Coronary artery disease is thought to begin with damage or injury to the inner layer of a coronary artery, sometimes as early as childhood. The damage may be caused by various factors, including:

• Smoking
• High blood pressure
• High cholesterol
• Certain diseases, such as diabetes
• Radiation therapy to the chest, as used for certain types of cancer

Once the inner wall of an artery is damaged, fatty deposits (plaques) accumulate. If the surface of these fatty deposits breaks or ruptures, blood cells called platelets will clump at the site to try to repair the artery. This clump can block the artery, leading to a heart attack.

Men are generally at greater risk of coronary artery disease than are women. However, the risk for women increases after menopause. A family history of heart disease and simply getting older increases the risk as well.

Other risk factors for coronary artery disease include:

• Smoking
• High blood pressure
• High cholesterol
• Diabetes
• Obesity
• Physical inactivity
• Stress and anger

Risk factors often occur in clusters and may feed one another, such as obesity leading to diabetes and high blood pressure. When grouped together, certain risk factors put you at an ever greater risk of coronary artery disease. For example, metabolic syndrome — a cluster of conditions that includes elevated blood pressure, high triglycerides, elevated insulin levels and excess body fat around the waist — greatly increases the risk of all types of heart disease.

Sometimes coronary artery disease develops without any classic risk factors. Researchers are studying other possible factors, including:

• C-reactive protein. Your liver produces C-reactive protein (CRP) in response to injury or infection. CRP is also produced by muscle cells within the coronary arteries. CRP is a general sign of inflammation, which plays a central role in atherosclerosis.
• Homocysteine. Homocysteine is an amino acid your body uses to make protein and to build and maintain tissue. But excessive levels of homocysteine may increase your risk of coronary artery disease and other cardiovascular conditions.
• Fibrinogen. Fibrinogen is a protein in your blood that plays a central role in blood clotting. But too much may promote excessive clumping of platelets, the type of blood cell largely responsible for clotting. That can cause a clot to form in an artery, leading to a heart attack or stroke. Fibrinogen may also be an indicator of the inflammation that accompanies atherosclerosis.
• Lipoprotein (a). This substance forms when a low-density lipoprotein (LDL) cholesterol particle attaches to a specific protein. The protein that carries lipoprotein (a) may disrupt your body's ability to dissolve blood clots. High levels of lipoprotein (a) may be associated with an increased risk of cardiovascular disease, including coronary artery disease and heart attack.

If you have risk factors for coronary artery disease, talk to your doctor. He or she may want to test you for the condition — especially if you have signs or symptoms of narrowed arteries. Even if you don't have evidence of coronary artery disease, your doctor may recommend aggressive treatment of your risk factors. Early diagnosis and treatment may stop progression of coronary artery disease and help prevent a heart attack.

The doctor will ask questions about your medical history, do a physical exam and order routine blood tests.  He or she may suggest one or more diagnostic tests as well, including:

• Electrocardiogram (ECG). An electrocardiogram records electrical signals as they travel through your heart. An ECG can often reveal evidence of a previous heart attack or one that's in progress. In other cases, Holter monitoring may be recommended. With this type of ECG, you wear a portable monitor for 24 hours as you go about your normal activities. Certain abnormalities may indicate inadequate blood flow to your heart.
• Echocardiogram. An echocardiogram uses sound waves to produce images of your heart. During an echocardiogram, your doctor can determine whether all parts of the heart wall are contributing normally to your heart's pumping activity. Parts that move weakly may have been damaged during a heart attack or be receiving too little oxygen. This may indicate coronary artery disease or various other conditions.

• Stress test. If your signs and symptoms occur most often during exercise, your doctor may ask you to walk on a treadmill or ride a stationary bike during an ECG. This is known as an exercise stress test. In other cases, medication to stimulate your heart may be used instead of exercise.

  Some stress tests are done using an echocardiogram. These are known as stress echos. For example, your doctor may do an ultrasound before and after you exercise on a treadmill or bike. Or your doctor may use medication to stimulate your heart during an echocardiogram.

  Another stress test known as a nuclear stress test helps measure blood flow to your heart muscle at rest and during stress. It's similar to a routine exercise stress test but with images in addition to an ECG. Trace amounts of radioactive material — such as thallium or a compound known as sestamibi (Cardiolite) — are injected into your bloodstream. Special cameras can detect areas in your heart that receive less blood flow.

• Angiogram. To view blood flow through your heart, your doctor may inject a special dye into your arteries before a chest X-ray. This is known as an angiogram. The dye outlines narrow spots and blockages on the X-ray images. If you have a blockage that requires treatment, a balloon or stent can be used to improve the blood flow in your heart.
• Electron beam computerized tomography (EBCT). This test, also called an ultrafast CT scan, can detect calcium within fatty deposits that narrow coronary arteries. If a substantial amount of calcium is discovered, coronary artery disease is likely. Other types of CT scans can also generate images of your heart arteries.
• Magnetic resonance angiography (MRA). This technique uses magnetic waves to produce a 3-D image of your coronary arteries, which your doctor can check for areas of narrowing or blockages — although the details may not be as clear as those provided by an angiogram.

When your coronary arteries narrow, your heart may not receive enough blood when demand is greatest — particularly during physical activity. This can cause chest pain or shortness of breath. If a cholesterol plaque ruptures, complete blockage of your heart artery may trigger a heart attack.

The lack of blood flow to your heart during a heart attack leads to irreversible damage to your heart muscle. The amount of damage depends in part on how quickly you receive treatment. If your heart has been damaged and can't pump enough blood to meet your body's needs, you may experience heart failure.

Lifestyle changes can promote healthier arteries. If you smoke, quitting is the most important thing you can do. Eat healthy foods, and exercise regularly. Sometimes medication or procedures to improve blood flow are recommended as well.

Medications
Various drugs can be used to treat coronary artery disease, including:

• Cholesterol medications. Aggressively lowering your low-density lipoprotein (LDL), or "bad," cholesterol can slow, stop or even reverse the buildup of fatty deposits in your arteries. Boosting your high-density lipoprotein (HDL), or "good," cholesterol may help, too. Your doctor can choose from a range of cholesterol medications, including drugs known as statins and fibrates.
• Aspirin. A daily aspirin or other blood thinner can reduce the tendency of your blood to clot, which may help prevent obstruction of your coronary arteries. If you've had a heart attack, aspirin can help prevent future attacks.
• Beta blockers. These drugs slow your heart rate and decrease your blood pressure, which decreases your heart's demand for oxygen. If you've had a heart attack, beta blockers reduce the risk of future attacks.
• Nitroglycerin. Nitroglycerin tablets, spray and patches can control chest pain by opening up your coronary arteries and reducing your heart's demand for blood.
• Angiotensin-converting enzyme (ACE) inhibitors. These drugs decrease blood pressure and may help prevent progression of coronary artery disease. If you've had a heart attack, ACE inhibitors reduce the risk of future attacks.
• Calcium channel blockers. These medications relax the muscles that surround your coronary arteries and cause the vessels to open, increasing blood flow to your heart. They also control high blood pressure.

Procedures to restore and improve blood flow
Sometimes more aggressive treatment is needed. Here are a few options:

• Angioplasty and stent placement (percutaneous coronary revascularization). In this procedure, your doctor inserts a long, thin tube (catheter) into the narrowed part of your artery. A wire with a deflated balloon is passed through the catheter to the narrowed area. The balloon is then inflated, compressing the deposits against your artery walls. A mesh tube (stent) is often left in the artery to help keep the artery open. Some stents slowly release medication to help keep the artery open.
• Coronary artery bypass surgery. A surgeon creates a graft to bypass blocked coronary arteries using a vessel from another part of your body. This allows blood to flow around the blocked or narrowed coronary artery. Because this requires open heart surgery, it's most often reserved for cases of multiple narrowed coronary arteries.
• Coronary brachytherapy. If the coronary arteries narrow again after stent placement, radiation may be used to help open the artery again.
• Laser revascularization. If standard treatments aren't effective, a new surgery known as laser revascularization may be considered. During this procedure, a laser beam is used to make tiny new channels in the wall of the heart muscle. New vessels may grow through these channels and into the heart to provide additional paths for blood flow.

On the research front
Researchers are exploring new techniques for treating coronary artery disease, such as gene therapy. In this experimental procedure, genes and growth factor proteins may be injected through a catheter or directly into the heart to stimulate growth of new blood vessels and restore blood flow to the heart. Gene-coated stents that could encourage the repair of coronary arteries are being studied as well.

Lifestyle changes can help you prevent or slow the progression of coronary artery disease.

• Stop smoking. Smoking is a major risk factor for coronary artery disease. Nicotine constricts blood vessels and forces your heart to work harder, and carbon monoxide reduces oxygen in your blood and damages the lining of your blood vessels. If you smoke, quitting is the best way to reduce your risk of a heart attack.
• Control your blood pressure. Ask your doctor for a blood pressure measurement at least every two years. He or she may recommend more frequent measurements if your blood pressure is higher than normal or you have a history of heart disease. Normal blood pressure is below 120 systolic/80 diastolic as measured in millimeters of mercury (mm Hg).
• Check your cholesterol. Ask your doctor for a baseline cholesterol test when you're in your 20s and then at least every five years. If your test results aren't within desirable ranges, your doctor may recommend more frequent measurements. Most people should aim for an LDL level below 130 mg/dL. If you have other risk factors for heart disease, your target LDL may be below 100 mg/dL. If you're at very high risk for heart disease — if you've already had a heart attack or have diabetes, for example — you may need to aim for an LDL level below 70 mg/dL.
• Keep diabetes under control. If you have diabetes, tight blood sugar control can help reduce the risk of heart disease.
• Get moving. Exercise helps you achieve and maintain a healthy weight and control diabetes, elevated cholesterol and high blood pressure — all risk factors for coronary artery disease. With your doctor's OK, aim for 30 to 60 minutes of physical activity most days of the week.
• Eat healthy foods. A heart-healthy diet based on fruits, vegetables and whole grains — and low in saturated fat, cholesterol and sodium — can help you control your weight, blood pressure and cholesterol. One or two servings of fish a week are also beneficial.
• Maintain a healthy weight. Being overweight increases your risk of coronary artery disease. Weight loss is especially important for people who have large waist measurements — more than 40 inches for men and more than 35 inches for women — because people with this body shape are more likely to develop diabetes and heart disease.
• Manage stress. Reduce stress as much as possible. Practice healthy techniques for managing stress, such as muscle relaxation and deep breathing.

In addition to healthy lifestyle changes, remember the importance of regular medical checkups. Some of the main risk factors for coronary artery disease — high cholesterol, high blood pressure and diabetes — have no symptoms in the early stages. Early detection and treatment can set the stage for a lifetime of better heart health.

Also ask your doctor about a yearly flu vaccine. Coronary artery disease and other cardiovascular disorders increase the risk of complications from the flu.