Myocardial Infarction

GENERAL INFORMATION:

What is a myocardial infarction? Your heart is always working to pump blood to your entire body. Blood carries oxygen and other things that your body needs in order to do its work. Your heart needs a constant supply of oxygen-rich blood for itself as well. The blood vessels that supply blood to your heart muscle are called coronary arteries. Sometimes one or more of the coronary arteries become too narrowed, completely blocked, or spasm (tighten). This causes part of the heart muscle to not get enough oxygen-rich blood that it needs to do its work. If the muscle goes too long without oxygen, it starts to die. This is called a myocardial (meye-oh-KAR-dee-al) infarction (in-FARK-shun), which is also called an MI or a heart attack.

What is the difference between angina and a myocardial infarction? Angina is chest pain, tightness, or discomfort that comes and goes. It is your heart muscle's way of telling you that it is not getting enough oxygen. Angina can be relieved (helped) with rest, oxygen, or special medicine. Angina does not cause the heart muscle to die, like an MI does. However, angina can be a warning sign that you may be at risk for an MI.

What causes a myocardial infarction?

• Blockage: The most common cause of an MI is fatty deposits (plaque) inside one or more of the coronary arteries. The disease that causes fatty deposits to narrow arteries in your heart and elsewhere in the body is called atherosclerosis. Atherosclerosis is also called "hardening of the arteries". The fatty deposits may cause your blood vessels to become too narrow, which can cause an MI. However, most MIs happen when a blood clot forms on the rough fatty deposits in a coronary artery, blocking it even more.
  
  
• Spasm: Sometimes a coronary artery can spasm (suddenly tighten) and cause blood flow to be cut off to part of the heart muscle. Most people with coronary artery spasms have fatty deposits as well. It is not known what causes most coronary artery spasms. Some things are known to cause coronary artery spasms, such as cocaine use.
  
  
• Other causes: Other conditions, such as certain heart valve problems, can cause blood clots that may lead to an MI. Sudden and severe (very bad) stress can trigger a heart attack as well. Talk to your caregiver if you have questions about what caused your MI.

Why do some people have heart disease and others do not? Certain things can increase your chance of having atherosclerosis and heart disease. You are able to change some of these risk factors. You are not able to change other risk factors. The following are factors that may increase your risk of heart disease and having an MI:

• A family history of heart problems.
  
  
• Atherosclerosis in other areas of the body. For example, you may have poor circulation (blood flow) in your legs, or carotid (neck) artery disease. You may have had a stroke in the past.
  
  
• Being overweight.
  
  
• Being a female who smokes and takes birth control pills.
  
  
• Being a female who has gone through the "change of life" (menopause).
  
  
• Cocaine use.
  
  
• Diabetes.
  
  
• High blood pressure.
  
  
• High blood cholesterol or having too much fat in your diet.
  
  
• Lack of exercise.
  
  
• Being male.
  
  
• Older age (over 55).
  
  
• Smoking now or in the past, or being exposed to cigarette smoke regularly.

What are the signs and symptoms of a myocardial infarction?

• The signs and symptoms of an MI may start slowly, or they may happen suddenly. The most common sign of an MI is chest pain, tightness, or pressure. The discomfort may feel crushing, tight, or heavy. The discomfort may range from mild to severe (very bad). It may spread to the neck, jaw, shoulders, back, or left arm. You may feel like you are having indigestion or burning under the breast bone in your upper chest. Other signs may include sweating, nausea (feeling sick to your stomach), vomiting (throwing up), or trouble breathing. Your skin may be pale, cool, or "clammy". You may feel lightheaded or weak.
  
  
• Some people may not have typical chest pain or pressure. Those most likely to have unusual symptoms when having an MI are women, and people who have diabetes. Their discomfort may be in an unusual place, such as the right arm or lower back. Sometimes symptoms like sweating, shortness of breath, dizziness, or nausea may be the only sign of a problem. Some people who are having an MI have no obvious symptoms at all. This is called a "silent" MI.
  
  
• A common problem with some people having an MI is denial. This is when the person does not admit to themselves or others that they are having symptoms of an MI. Unfortunately, this denial may cause the person to put off seeking medical help. This delay in treatment can be dangerous, even life-threatening.

What should I do if I think I may be having a myocardial infarction? Call 9-1-1 or 0 for an ambulance at the first signs of an MI. In most areas, you can receive life-saving care much earlier by calling an ambulance to take you to the hospital. Most ambulances carry medicines, oxygen, and other equipment so that your treatment can start right away. Quick treatment of an MI can save your life. Every minute you wait to be treated may cause an increase in permanent (life-long) damage to your heart. Never try to drive yourself to the hospital if you think you are having a heart problem. People having heart problems may pass out (faint) without warning, making it dangerous to drive.

How is a myocardial infarction diagnosed?

• Sometimes it is hard to tell the difference between an MI and other causes of chest discomfort. You will need to be seen by a caregiver for tests to know for sure if you are having an MI or not. Your caregiver will review your medical history and the symptoms you are having. A test called an ECG may be done to look for problems or damage in different areas of the heart. Your caregiver may do tests on your blood and urine to get important information about your health. You may need a chest x-ray to check your heart and your lungs. You may also need an ultrasound of your heart called an echocardiogram.
  
  
• You may need a more detailed test called a cardiac catheterization, or "heart cath". This procedure uses dye and a special x-ray to check the blood flow in your coronary arteries. A heart cath can help your caregiver decide how your heart problem should be treated. Sometimes blockages in the coronary arteries can be treated during a heart cath.

How is a myocardial infarction treated? Your treatment may include the following:

• Emergency treatment:
  
  
  • A life-threatening problem that may happen during and after an MI is arrhythmias (ah-RITH-mee-ahs). Arrhythmias are irregular heartbeats or heart rhythms. Arrhythmias that happen during an MI can cause sudden death. You will be hooked up to a heart monitor so that caregivers can watch for arrhythmia problems. Some arrhythmias may be treated with medicine, but some need even faster treatment. Emergency arrhythmia treatment may include defibrillation. This procedure uses an electric shock that is given to the heart. The shock is usually given through paddles or sticky patches placed on your chest or back. The shock may help your heart return to a normal beat. You may need this more than once.
    
    
  • If your heart rhythm is very bad, you may not have a heartbeat (pulse). If you stop breathing or do not have a pulse, you may need CPR. CPR is when caregivers or a specially-trained bystander gives you breaths and sometimes chest compressions. This may help your body get oxygen and some blood flow while you do not have a pulse or are not breathing on your own.
  
  
• Medicines and oxygen: You may need extra oxygen until your heart is getting better blood flow. You may get oxygen through a mask or nasal cannula (plastic nose prongs). You may be given medicine to break up clots that are blocking your heart arteries. Blood thinners may be given to keep you from having more blood flow problems in your heart. You may also receive nitroglycerin ("nitro"), and morphine or another kind of pain medicine. You may need medicine to help your heart beat normally, or decrease how hard your heart needs to work. Some medicines may keep you from having spasms in your coronary arteries. You may need to keep taking several medicines after you recover from your MI. Tell your caregiver about all medicines that you use because it is very dangerous to use certain medicines together.
  
  
• Angioplasty and other procedures: Heart catheterization is an angiogram of the heart arteries to look for blockages. If there are blockages an angioplasty and other procedures may be performed. During an angioplasty, your caregiver makes a small puncture hole into one or more blood vessels (usually in the groin area). A small wire with a balloon on the end is sent up into a blocked artery in your heart. The caregiver inflates the balloon to push the fatty deposits against the artery wall. This makes more room for blood to flow. Sometimes a stent is put in. A stent is a metal mesh tube that is placed in the artery to help it stay open after an angioplasty. Angioplasty and stenting is done during a cardiac catheterization. An arthrectomy may also be done to remove plaque from your coronary arteries.
  
  
• Coronary artery bypass graft (CABG) surgery: This surgery is also known as heart bypass surgery, open-heart surgery, or a "cabbage". A CABG can improve blood flow to the heart by sending blood around a blocked part of an artery. This surgery may also decrease your risk of having an MI (heart attack) in the future.
  
  
• Control of risk factors: High blood pressure, high blood cholesterol, diabetes, and being overweight increases your risk of heart problems. If you have any of these medical conditions, ask caregivers for help to control them. Smoking can further damage your heart, as well as your blood and lungs. With time, this can cause a stroke or another MI. It is very important to stop smoking.

What are the risks of having a myocardial infarction? The risks from an MI may depend on what part of your heart was damaged and how much was damaged. The sooner you receive treatment, the less damage you may have to your heart. The more damage there is, the more likely you will have heart failure. Even with treatment, you may die from an MI. Some emergency treatments may save your life, but cause other problems. Clot busters and blood thinning medicines may cause bleeding problems. CPR may cause you to have bruising, pain, and even broken bones in your chest. Defibrillation may cause burns on the skin of your chest or back. Talk to your caregiver if you are worried or have questions about your medicine or care.

Where can I go for support and more information?

• Having an MI is a life-changing event for you and your family. Accepting that you have a heart problem is hard. You and those close to you may feel angry, sad, or frightened. These feelings are normal. Talk to your caregivers, family, or friends about your feelings. Let them help you. Encourage those close to you to talk to your caregiver about how things are at home. Your caregiver can help your family better understand how to support a person after having an MI.
  
  
• You may want to join a support group. This is a group of people who also have heart problems. Ask your caregiver for the names and numbers of support groups in your area. You and your family may also want to learn CPR. A CPR class teaches how to help a person who is not breathing or has no heartbeat. You can contact the following national organizations for more information about heart disease or CPR.
  • American Heart Association National Center
    7272 Greenville Avenue
    Dallas, TX 75231-4596
    Phone: 1-800-242-8721
    Web Address: http://www.americanheart.org
    
  • American Red Cross National Headquarters
    2025 E Street NW
    Washington, DC 20006
    Phone: 1-202-303-4498
    Web Address: http://www.redcross.org
    
  • National Heart, Lung and Blood Institute
    Health Information Center
    P.O. Box 30105
    Bethesda, MD 20824-0105
    Phone: 1-301-592-8573
    Web Address: http://www.nhlbi.nih.gov/health/infoctr/index.htm
    

CARE AGREEMENT:

You have the right to help plan your care. To help with this plan, you must learn about your health condition and how it may be treated. You can then discuss treatment options with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.

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