A heart attack (myocardial infarction) happens when one or more areas of the heart muscle don't get enough oxygen. 当流向心脏肌肉的血液被阻塞时，就会发生这种情况.

心脏病发作的原因

The blockage is caused by a buildup of plaque in the arteries (atherosclerosis). 斑块是由沉积物组成的， cholesterol，及其他物质. 当斑块破裂时，血凝块很快形成. 血凝块是心脏病发作的真正原因.

如果血液和氧气供应被切断, muscle cells of the heart begin to suffer damage and start to die. 堵塞后30分钟内会造成不可逆转的损害. The result is heart muscle affected by the lack of oxygen no longer works as it should.

谁有心脏病发作的风险?

心脏病发作的危险因素有两种.

遗传(基因)因素:谁是最危险的?

以下人群的风险最大:

• 患有遗传性疾病的人 高血压(高血压)
• 遗传的高密度脂蛋白胆固醇水平低的人, 高水平的低密度脂蛋白胆固醇, 或者甘油三酯水平高
• 有心脏病家族史的人. This is especially true if the heart disease started before age 55.
• Older men and women
• People with type 1 diabetes
• 经历更年期的妇女. 一般来说，男性比女性在更年轻的时候就有风险. 绝经后，女性同样面临风险.

获得性风险因素:谁的风险最大?

• 获得性高血压患者(高血压)
• 高密度脂蛋白胆固醇水平较低的人, 高水平的低密度脂蛋白胆固醇, 或者甘油三酯水平高
• Cigarette smokers
• 压力很大的人
• 喝太多酒的人
• 久坐不动的人
• 超重30%以上的人
• 吃饱和脂肪含量高的食物的人
• 2型糖尿病患者

心脏病发作可能发生在任何人身上. When you take the time to learn which risk factors apply to you, 你可以采取措施消除或减少它们.

管理心脏病发作的危险因素

以下是控制心脏病发作风险的方法:

• Look at which risk factors apply to you, then take steps to eliminate or reduce them.
• 了解高血压和高胆固醇水平. 这些可能是“沉默的杀手”."
• Change risk factors that aren't inherited by making lifestyle changes. 与您的医疗保健提供者谈谈，了解如何做到这一点.
• Talk with your healthcare provider to find out if you have risk factors that can't be changed. 这些可以通过药物和改变生活方式来控制.

预防心脏病发作

You can help prevent a heart attack by knowing your risk factors for coronary artery disease and heart attack and taking action to lower those risks. Even if you’ve already had a heart attack or are told that your chances of having a heart attack are high, 你仍然可以降低你的风险, most likely by making a few lifestyle changes that promote better health.

• Don’t smoke. Your doctor may recommend methods for quitting, including nicotine replacement.
• 吃低脂肪、低胆固醇和低盐的食物.
• See your doctor regularly for blood pressure and cholesterol monitoring.
• 进行适度的、有规律的有氧运动. People over age 50 who have led a sedentary lifestyle should check with a doctor before beginning an exercise program.
• 如果你超重，就减肥.
• Your doctor may advise you to take a low dose of aspirin regularly. Aspirin reduces the tendency for the blood to clot, thereby decreasing the risk of heart attack. However, such a regimen should only be initiated under a doctor’s expressed recommendation.
• Women at or approaching menopause should discuss the possible cardio-protective benefits of estrogen replacement therapy with their doctor.

心脏病发作的症状

The following are the most common symptoms of a heart attack. 但每个人的症状可能略有不同.

• Severe pressure, fullness, squeezing, pain, or discomfort in the center of the chest that lasts for more than a few minutes
• Pain or discomfort that spreads to the shoulders, neck, arms, or jaw
• 胸痛越来越严重
• Chest pain that doesn't get better with rest or by taking nitroglycerin
• 伴随以下症状的胸痛:
  • 出汗，冷，皮肤潮湿或苍白
  • Shortness of breath
  • Nausea or vomiting
  • 头晕或昏厥
  • 无法解释的虚弱或疲劳
  • 快速或不规则脉搏

Although chest pain is the key warning sign of a heart attack, 它可能与其他病症混淆. 包括消化不良, pleurisy, pneumonia, tenderness of the cartilage that attaches the front of the ribs to the breastbone, and heartburn. 经常去看你的医疗保健提供者进行诊断.

应对心脏病发作的警告信号

If you or someone you know has any of the above warning signs, act right away. 拨打911或当地的紧急电话.

治疗心脏病

治疗心脏病的目的是减轻疼痛, 保持心肌功能, and prevent death.

急诊科的治疗包括:

• 静脉注射治疗，如硝酸甘油和吗啡
• 持续监测心脏和生命体征
• Oxygen therapy to improve oxygenation to the damaged heart muscle
• 减轻疼痛的止痛药. 这反过来又减少了心脏的负荷. 心脏的需氧量减少.
• Cardiac medicine such as beta-blockers to promote blood flow to the heart, 改善血液供应, prevent arrhythmias, 降低心率和血压
• 纤溶治疗. This is the intravenous infusion of a medicine that dissolves the blood clot, restoring blood flow.
• Antithrombin or antiplatelet therapy with aspirin or clopidogrel. 这是用来防止进一步的血液凝固.
• Antihyperlipidemics. These medicines lower lipids (fats) in the blood, particularly low density lipid (LDL) cholesterol. 他汀类药物是一类抗高脂血症药物. 它们包括辛伐他汀、阿托伐他汀和普伐他汀. 胆汁酸的隔离剂——colesvelam, cholestyramine, and colestipol—and nicotinic acid (niacin) are two other types of medicines that may be used to lower cholesterol levels.

You may need other procedures to restore blood flow to the heart. 这些程序描述如下.

冠状动脉血管成形术

通过这个过程, a balloon is used to create a bigger opening in the vessel to increase blood flow. This is often followed by inserting a stent into the coronary artery to help keep the vessel open. Although angioplasty is done in other blood vessels elsewhere in the body, percutaneous coronary intervention (PCI) refers to angioplasty in the coronary arteries. 这让更多的血液流入心脏. PCI is also called percutaneous transluminal coronary angioplasty (PTCA). PTCA程序有几种类型:

• Balloon angioplasty. A small balloon is inflated inside the blocked artery to open the blocked area.
• 冠状动脉支架. A tiny coil is expanded inside the blocked artery to open the blocked area. 支架留在原位以保持动脉畅通.
• Atherectomy. The blocked area inside the artery is cut away by a tiny device on the end of a catheter.
• Laser angioplasty. 一种用于“蒸发”动脉阻塞的激光.

冠状动脉搭桥术

This surgery is most commonly referred to as simply bypass surgery or CABG (pronounced "cabbage"). It is often done in people who have chest pain (angina) and coronary artery disease. Coronary artery disease is when plaque has built up in the arteries. During the surgery, the surgeon makes a bypass by grafting a piece of a vein above and below the blocked area of a coronary artery. 这样可以让血液在堵塞的地方流动. 外科医生通常从腿部取静脉, 但他或她也可能使用来自胸部或手臂的动脉. Sometimes, you may need more than one bypass surgery to restore blood flow to all areas of the heart.