Myocardial Infarction

What is a myocardial infarction?

A myocardial infarction (MI) is a heart attack. A heart attack happens when the blood vessels that supply blood to your heart (coronary arteries) are blocked. This causes areas of your heart muscle to die.

What are the signs and symptoms of a myocardial infarction?

Chest pain is the most common symptom. Your chest may feel tight or heavy. You may feel pressure, crushing, squeezing, or burning. The discomfort may spread to your neck, jaw, shoulders, back, or arms. Your symptoms may happen when you are at rest, active, eating, stressed, or cold. The chest pain can last 30 minutes or longer. The following are also signs and symptoms of an MI:

• You have heartburn, abdominal pain, nausea, or vomiting.
  
  
• You feel weak, dizzy, or like you are going to faint.
  
  
• You feel like you cannot catch your breath.
  
  
• You are cold and sweaty.
  
  
• You feel like your heart is beating very fast.
  
  
• You may not have typical chest pain or pressure if you are a woman, an older adult, or have diabetes or a history of heart failure. You may have shortness of breath and no other symptoms. You may have no symptoms at all.

What is the difference between angina and a myocardial infarction?

Angina is chest pain, tightness, or discomfort that comes and goes. It gets worse with activity or stress. It gets better with rest, medicine called nitroglycerin, or both. Angina does not cause areas of the heart muscle to die, like an MI does. Angina may be a warning sign that you are at risk for an MI. Ask your caregiver for more information on angina.

What causes a myocardial infarction?

Ask your caregiver about these and other causes of MI:

• Plaque: Plaque (fatty deposits) can build up inside one or more of your coronary arteries. This can cause the arteries to become narrow and slow or block the blood flow. Small pieces can also break off and block blood flow.
  
  
• Blood clots: Blood clots may form on each side of the plaque. This can slow or stop blood flow to your heart.
  
  
• Heart spasm: A heart spasm is when a coronary artery suddenly tightens and causes blood flow to be stopped to part of the heart muscle.

What increases my risk for a myocardial infarction?

• You have high cholesterol.
  
  
• You have diabetes or high blood pressure.
  
  
• You smoke cigarettes or chew tobacco.
  
  
• A person in your family had an MI.
  
  
• You are a man over the age of 55.
  
  
• You are a woman who has gone through menopause.
  
  
• You use drugs such as cocaine and methamphetamines.
  
  
• You are obese.

How is a myocardial infarction diagnosed?

Your caregiver will ask about your signs and symptoms and examine you. He will ask when your chest pain started, what it feels like, and if anything makes it better or worse. He will ask if you took nitroglycerin or other medicines. He will ask you about your medical history and if you have had these signs and symptoms before. Ask your caregiver about these and other tests you may need:

• Blood tests: Certain blood tests can help caregivers know if your heart muscle has been damaged. The blood may be taken from your hand, arm, or IV. You may need blood tests more than once.
  
  
• Chest x-ray: This is a picture to check the condition of your lungs and heart. Caregivers use it to look for an enlarged heart or fluid in your lungs.
  
  
• Heart monitor: This test is also called an EKG or ECG. Sticky pads are placed on your skin to record your heart's electrical activity. An EKG gives information about how your heart is working. Lie as still as possible during the test.
  
  
• Echocardiogram: This test is a type of ultrasound. Sound waves are used to show the structure, movement, and blood vessels of your heart.
  
  
• Angiogram: This is a test to look for blockage in your coronary arteries, such as plaque or blood clots. It is also called a cardiac catheterization. During an angiogram, a catheter (long, thin, bendable tube) is put into an artery, usually in your groin. Sometimes the catheter is put into a different artery, such as one in your arm. Special dye is put through the catheter and x-ray pictures are taken of the blood flow. The dye helps caregivers see your blood vessels better. Tell caregivers if you have an allergy to iodine or shellfish.

What medicines are used to treat a myocardial infarction?

Ask your caregiver about these and other medicines you may need:

• Nitroglycerin: This medicine may also be called nitro. Nitroglycerin opens the arteries to your heart so the heart gets more oxygen. Nitroglycerin can be given in an IV, by mouth, or put on your body as a patch or paste.
  
  
• Angiotensin-converting enzyme inhibitors: These medicines are called ACE inhibitors. They help relax your blood vessels so your heart can get the blood it needs. You may need angiotensin II receptor blockers (ARBs) if you cannot take ACE inhibitors.
  
  
• Aldosterone antagonists: These medicines helps remove extra fluid from your body and protects your heart from more damage.
  
  
• Beta blockers: These medicines help you have a steady and regular heartbeat.
  
  
• Calcium channel blockers: These medicines help slow your heartbeat. They also help open up small blood vessels. This can relieve chest pain, control an abnormal heartbeat, and decrease blood pressure.
  
  
• Aspirin: This medicine may be given to help thin the blood to keep blood clots from forming. This medicine makes it more likely for you to bleed or bruise.
  
  
• Clot busters: This medicine helps break apart blood clots, which may increase blood flow to your heart muscle. It is given in your IV and may be given at the same time as other blood thinners. This medicine may decrease the amount of damage to your heart muscle, and may even save your life. You will bleed and bruise more easily after getting clot busters.
  
  
• Pain medicine: Caregivers may give you medicine to take away or decrease your pain. Tell caregivers right away if you continue to feel discomfort, pressure, burning, or tightness in your chest.
  
  
• Cholesterol medicine: This medicine decreases the amount of plaque in the blood.

What procedures are used to treat a myocardial infarction?

Ask your caregiver about these and other treatments you may need:

• Oxygen: You may need extra oxygen if your blood oxygen level is lower than it should be. You may get oxygen through a mask placed over your nose and mouth or through small tubes placed in your nostrils. Ask your caregiver before you take off the mask or oxygen tubing.
  
  
• Angioplasty: A percutaneous coronary angioplasty may be done to open an artery blocked by plaque. A special tube with a balloon on the end is threaded into the blocked artery. Once the tube is in the artery, the balloon is filled with contrast dye. As the balloon fills, it presses the plaque against the artery wall to open the artery so blood can flow through it more easily.
  
  
• Coronary intravascular stent placement: This is also called coronary artery stenting. The stent is a small mesh wire that is inserted into an artery to keep it open so blood can flow through it. When the stent is expanded by the balloon, it attaches to the artery wall and keeps the artery open.
  
  
• Coronary artery bypass graft (CABG) surgery: This surgery is also known as heart bypass surgery or open-heart surgery. 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 in the future.

What should I do if I think I am having a myocardial infarction?

If you have chest pain for 2 to 3 minutes, stop what you are doing. If the pain does not go away immediately, take 1 dose of nitroglycerin as directed. Call 911 if your chest pain does not go away or gets worse within 5 minutes. Sit or lie down while you wait for the ambulance. You can take up to 2 more doses of nitroglycerin (5 minutes apart) if your chest pain does not go away.

What lifestyle changes may be needed after a myocardial infarction?

• Go to cardiac rehabilitation as directed: Cardiac rehabilitation, or cardiac rehab, is a program that helps you learn how to live a more heart-healthy lifestyle. Cardiac rehab may help decrease your risk of having heart problems in the future. You may learn how to exercise safely to strengthen your heart and other muscles.
  
  
• Eat a heart healthy diet: Get enough calories, protein, vitamins, and minerals to help prevent poor nutrition and promote muscle strength. You may be told to eat foods low in cholesterol or sodium (salt). You also may be told to limit saturated and trans fats. Eat foods that contain healthy fats, such as walnuts, salmon, and canola and soybean oils. Eat foods that help protect the heart, including plenty of fruits and vegetables, nuts, and sources of fiber.
  
  
• Do not smoke: Smoking increases your risk of blood vessel disease and an MI. Smoking causes lung cancer and other long-term lung diseases.
  
  
• Return to daily activities as directed: Talk to your cardiologist (heart specialist) before you drive. Ask him when you can go back to work and when you can have sex. Ask when you can climb stairs, do house or yard work, and how much you can lift.
  
  
• Get vaccinated: Get an influenza (flu) vaccine every year as soon as it is available. The vaccine will help prevent the flu. Ask about other vaccinations you may need.
  
  
• Exercise as directed: Exercise makes your heart stronger, lowers blood pressure, and helps prevent an MI. Begin with easy exercises, such as walking. Avoid intense exercise. The goal is 30 to 60 minutes a day, 5 to 7 days a week. Ask your cardiologist how often and how long to exercise.
  
  
• Manage your weight: Weight loss can decrease your risk of an MI. The goal for women is a waist size less than 35 inches around. The goal for men is a waist size less than 40 inches around. Ask your cardiologist if you need to lose weight and how much you should lose. Ask him about the best plan for you to lose weight.
  
  
• Manage your stress: Stress may slow healing and lead to illness. Learn ways to control stress, such as relaxation, deep breathing, and music. Talk to someone about things that upset you.

What are the risks of a myocardial infarction?

Damage to your heart can lead to an abnormal heart rhythm. You may go into cardiogenic shock, which means your heart cannot get enough blood to your organs. You may develop heart failure. The damage from the MI may cause your heart to rupture (burst open). An MI can be life-threatening. Clot busters and blood thinning medicines may cause bleeding problems.

Where can I go for support and more information?

• American Heart Association
  7272 Greenville Avenue
  Dallas , TX 75231-4596
  Phone: 1- 800 - 242-8721
  Web Address: http://www.heart.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
  

When should I contact my caregiver?

Contact your caregiver if:

• You have trouble taking your heart medicine.
  
  
• You have questions or concerns about your condition or care.

When should I seek immediate help?

Seek care immediately or call 911 if:

• Call 911 or an ambulance if you have any signs of a heart attack:
  
  
  • Discomfort in the center of your chest that feels like squeezing, pressure, fullness, or pain, that lasts for more than a few minutes or keeps returning
    
    
  • Discomfort or pain in your back, neck, jaw, stomach, or one or both of your arms
    
    
  • Feeling sick to your stomach
    
    
  • Having trouble breathing
    
    
  • A sudden cold sweat, particularly in combination with chest discomfort or trouble breathing
    
    
  • Feeling very lightheaded or dizzy, particularly in combination with chest discomfort or trouble breathing
  
  
• You are tired and cannot think clearly.
  
  
• Your heart is beating faster than usual.
  
  
• You are bleeding from your gums or nose.
  
  
• You see blood in your urine or bowel movements
  
  
• You urinate less than usual or not at all.
  
  
• You have new or increased swelling in your feet or ankles.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment.

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