Coronary artery disease, also called coronary heart disease, or simply, heart disease, is the No. 1 killer in America, affecting more than 13 million Americans.

Heart disease is a result of plaque buildup in a person's arteries, which blocks blood flow and heightens the risk for heart attack and stroke.

Heart disease is a result of plaque buildup in a person's coronary arteries — a condition called atherosclerosis — that leads to blockages. The arteries, which start out smooth and elastic, become narrow and rigid, restricting blood flow to the heart. The heart becomes starved of oxygen and the vital nutrients it needs to pump properly.

From a young age, cholesterol-laden plaque can start to deposit in the blood vessel walls. As you get older, the plaque burden builds up, inflaming the blood vessel walls and raising the risk of blood clots and heart attack. The plaques release chemicals that promote the process of healing but make the inner walls of the blood vessel sticky. Then, other substances, such as inflammatory cells, lipoproteins, and calcium that travel in your bloodstream start sticking to the inside of the vessel walls.

Eventually, a narrowed coronary artery may develop new blood vessels that go around the blockage to get blood to the heart. However, during times of increased exertion or stress, the new arteries may not be able to supply enough oxygen-rich blood to the heart muscle.

In some cases, a blood clot may totally block the blood supply to the heart muscle, causing heart attack. If a blood vessel to the brain is blocked, usually from a blood clot, an ischemic stroke can result. If a blood vessel within the brain bursts, most likely as a result of uncontrolled hypertension (high blood pressure), a hemorrhagic stroke can result.

Cardiac ischemia occurs when plaque and fatty matter narrow the inside of an artery to a point where it cannot supply enough oxygen-rich blood to meet your heart's needs. Heart attack can occur - with or without chest pain and other symptoms.

Ischemia is most commonly experienced during:

●Exercise or exertion

●Eating

●Excitement or stress

●Exposure to cold

Coronary artery disease can progress to a point where ischemia occurs even at rest. And ischemia can occur without any warning signs in anyone with heart disease, although it is more common in people with diabetes.

The most common symptom of coronary artery disease is angina, or chest pain. Angina can be described as a heaviness, pressure, aching, burning, numbness, fullness, squeezing or painful feeling. It can be mistaken for indigestion or heartburn. Angina is usually felt in the chest, but may also be felt in the left shoulder, arms, neck, back, or jaw.

Other symptoms that can occur with coronary artery disease include:

●Shortness of breath

●Palpitations (irregular heart beats, skipped beats, or a “flip-flop” feeling in your chest)

●A faster heartbeat

●Weakness or dizziness

●Nausea

●Sweating

To find out if one person has or is at risk for coronary artery disease, the doctor will do a physical exam and check his risk based on his health and risk factors.

You may then have several different kinds of tests to check your risk for getting heart disease. If your doctor thinks you have heart disease, you will need more tests to make sure.

The main tests your doctor uses to check your risk for getting heart disease include:

●Blood pressure. High blood pressure increases your risk for heart disease.

●Cholesterol (a blood test). High cholesterol increases your risk for heart disease.

Your doctor will use your blood pressure, cholesterol, and other risk factors such as your age and if you smoke, to know your risk of heart disease. If you know your blood pressure and cholesterol levels, you can check your risk for a heart attack.

Other tests may help your doctor find out your risk for heart disease, especially when they are considered along with your other risk factors. But these tests are not helpful for everyone. Such tests may include:

●C-reactive protein (CRP) test. High CRP levels are linked to higher risk for heart disease.

●Coronary calcium scan. This test uses a special kind of X-ray to check for buildup of calcium in the heart's arteries. The result is a number, or score. If you have a high score, you may need more tests to check for heart disease or to find out how bad it is. For more information, see.

Sometimes doctors schedule routine tests because they think that's what patients expect. But experts say routine heart tests can be a waste of time and money. See the topic Heart Tests: When Do You Need Them?

If your doctor thinks you may have heart disease, you will need some tests to make sure. Most often, the first tests include:

●An electrocardiogram (EKG or ECG).

●A chest X-ray.

●Blood tests.

●An exercise electrocardiogram. This is also called a “stress test.”

Other tests may include:

●Cardiac perfusion scan. This test shows if you have enough blood flow to the heart.

●Echocardiogram and stress echocardiogram. This test uses ultrasound to see areas of poor blood flow in the heart. It can also check how well your heart is working after a heart attack. The test can help your doctor find out how much blood your heart is pumping during each heartbeat (ejection fraction).

●Coronary angiogram. This is an X-ray test that creates pictures of the blood flow through your coronary arteries. It allows your doctor to see any blockage or narrowing of the artery. It's done using a soft, thin tube (catheter) that is put in a blood vessel in the arm or groin and gently moved into the heart. For more information, see the topic.

●CT angiogram. CT (computed tomography) angiograms use X-rays to get detailed pictures of the heart and its blood vessels.

Treatment for coronary artery disease involves making lifestyle changes, taking medications, possibly undergoing invasive and/or surgical procedures, and seeing your cardiologist for regular checkups.

●Reduce your risk factors. If you smoke, quit. Avoid high-cholesterol foods and adopt a low-fat, low-salt diet. Keep your blood sugar in control if you have diabetes. Exercise more to maintain a healthy weight (but talk to your doctor before you starting an exercise program).

●Medications. If making lifestyle changes isn't enough to control your heart disease, medications may be needed to help your heart work more efficiently and receive more oxygen-rich blood. The drugs you are on depend on you and your specific heart problem.

●Surgery and other procedures. Common procedures to treat coronary artery disease include balloon angioplasty (PTCA), stent placement, and coronary artery bypass surgery. All of these procedures increase blood supply to your heart, but they do not cure coronary heart disease. You will still need to decrease your risk factors to prevent future disease.

Doctors are also studying several innovative ways to treat heart disease. Here are a couple of the more promising ones:

●Angiogenesis. This involves giving substances, such as stem cells and other genetic material, through the vein or directly into damaged heart tissue to trigger the growth of new blood vessels to bypass the clogged ones.

●EECP (Enhanced External Counterpulsation). Patients who have chronic angina but are not helped by nitrate medications or who do not qualify for various surgeries and procedures may find relief with EECP. The outpatient procedure involves using treatment cuffs placed on the legs that inflate and deflate, increasing the blood supply that feeds coronary arteries.

Learn to recognize your heart disease symptoms and the situations that cause them. Call your doctor if you begin to have new symptoms or if they become more frequent or severe. If you or someone you are with experiences chest discomfort, especially if there is shortness of breath, heart palpitations, dizziness, a fast heart beat, nausea or sweating, don't wait longer than a few minutes to call 911 for help.

If you have angina and have been prescribed nitroglycerin, call your doctor or have someone take you to the nearest emergency room if pain persists after taking two doses (taken at five-minute intervals) or after 15 minutes.

Emergency personnel may tell you to chew an aspirin to help break up a possible blood clot, if there is not a medical reason for you to avoid aspirin.

If you smoke, quit. You should also get in the habit of exercising, because exercise strengthens the heart and blood vessels, reduces stress, and has been shown to reduce blood pressure while also boosting HDL (good) cholesterol levels. Numerous studies done in recent decades indicate that drinking alcohol in moderation may actually reduce the risk of heart disease. But more than one drink a day, or a few drinks per week, is not recommended.

For many people, learning to relax can help prevent and treat heart disease. While success varies from person to person, stress-reduction techniques have been shown to moderate high blood pressure, heart arrhythmias, and emotional responses such as anxiety, anger, and hostility that have been linked to coronary heart disease, angina, and heart attack. The choice of relaxation technique is up to you. Some that have proved beneficial are meditation, progressive relaxation, yoga, and biofeedback training.

Even modest changes in diet and lifestyle can significantly reduce the risk of heart disease. Being overweight, especially in the mid-section, can lead to high blood pressure and diabetes. If you are 20% or more over the ideal weight for your age, height, and sex, you put a strain on your heart's ability to pump blood efficiently. Although lowering sodium, cholesterol and saturated fat consumption are important for lowering blood pressure and reducing the risk of coronary heart disease, equally vital is increasing intake of fresh fruits and vegetables, whole unprocessed high-fiber grains, and vegetarian sources of fats and proteins (as from fish, nuts, seeds, soy-based items, avocados, etc.).

alcohol ['ælkəhɒl] n.酒精，乙醇

angina [æn'dʒainə] n.心绞痛；咽喉痛；咽峡炎

angiogenesis [,ændʒiə(ʊ)'dʒenisis] n.血管生成；血管再生术

atherosclerosis [,æθərəʊskliə'rəʊsis] n.动脉粥样硬化；动脉硬化

biofeedback [baiəʊ'fːdbæk] n.生物反馈

boosting [buːst] vt.促进；增加；支援

calcium ['kælsiəm] n.钙

cardiologist ['kɑrdi'ɑlədʒist] n.心脏病学家；心脏病科医师

cholesterol [kə'lestərɒl] n.胆固醇

coronary ['kɒr(ə)n(ə)ri] adj.冠的；冠状的；

deposit [di'pɒzit] n.沉淀物；vt.使沉积；存放；vi.沉淀

echocardiogram [,ɛko'kɑrdiə,græm] n.超声波心动图，心回波图

elastic [i'læstik] adj.有弹性的；灵活的；易伸缩的；n.松紧带；橡皮圈

electrocardiogram(EKG or ECG) [i,lektrəʊ'kɑːdiəgræm] n.心电图

emergency [i'mɜːdʒ(ə)nsi] n.紧急情况；突发事件；非常时刻；adj.紧急的

groin [grɒin] n.腹股沟

heartburn ['hɑːtbɜːn] n.心痛，妒忌；［内科］胃灼热

ischemic [i'skemik] adj.缺血性的；局部缺血的

lipoproteins [,lipəu'prəutin] n.脂蛋白

numbness ['nʌmnəs] n.麻木；麻痹

palpitations [,pælpi'teʃnz] n.心悸

perfusion [pɚ'fjʊʒən] n.灌注；充满

plaque [plæk; plɑːk] n.血小板

rigid ['ridʒid] adj.严格的；僵硬的，死板的；坚硬的；精确的

saturated ['sætʃəreitid] adj.饱和的；渗透的；深颜色的；v.使渗透，使饱和（saturate的过去式）

sodium ['səʊdiəm] n.钠（11号元素，符号 Na）

squeeze [skwiːz] vt.挤；紧握；勒索；vi.压榨；n.压榨；紧握；拥挤

starve [stɑːv] vi.饿死；挨饿；渴望；vt.使饿死；使挨饿

sticky ['stiki] adj.黏的；黏性的

stroke [strəʊk] n.中风

vegetarian [vedʒi'teəriən] n.素食者；食草动物；adj.素食的

yoga ['jəʊgə] n.瑜伽；瑜伽术

balloon angioplasty 气囊血管成形术；球囊成形术

coronary artery disease 冠状动脉疾病；冠心病

C-reactive protein (CRP) C反应蛋白

EECP (Enhanced External Counterpulsation) 增强型体外反搏

ejection fraction 射血分数；射出分率

HDL (high density lipoprotein) 高密度脂蛋白

PTCA (Percutaneous Transluminal Coronary Angioplasty) 经皮腔内冠状动脉成形术

stent placement 支架植入