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.

Tests: You may need one or more of the following tests. The results of these tests help caregivers plan the best way to treat you.

• Arterial line: An arterial line is a tube that is placed into an artery (blood vessel), usually in the wrist or groin. The groin is the area where your abdomen meets your upper leg. An arterial line may be used for measuring your blood pressure or for taking blood.
  
• Blood tests: You may need blood taken for tests. The blood can be taken from a blood vessel in your hand, arm, or the bend in your elbow. It is tested to see how your body is doing. It can give your caregivers more information about your health condition. You may need to have blood drawn more than once.
  
• Blood gases: This test is also called an arterial blood gas or ABG test. Blood is taken from an artery (blood vessel) in your wrist, arm, or groin. The groin is the area where your abdomen meets your upper leg. Your blood is tested for the amount of "gases" in it, such as oxygen, acids, and carbon dioxide.
  
• Cardiac catheterization: This is a test to see how well your heart is working. Your arteries (blood vessels) may also be checked to see if they are blocked. A special tube is threaded into your heart through a blood vessel in your leg or arm. Dye may be given so x-ray pictures of your arteries show up better on a TV-like screen.
  
• Chest x-ray: This is a picture of your lungs and heart. Caregivers use it to see how your lungs and heart are doing. Caregivers may use the x-ray to look for signs of infection like pneumonia, or to look for collapsed lungs. Chest x-rays may show tumors, broken ribs, or fluid around the heart and lungs.
  
• CVP line: A CVP line is also called a central line. It is an IV catheter or tube. It is put into a large blood vessel near your collarbone, in your neck, or in your groin. The groin is the area where your abdomen meets your upper leg. The CVP line may be used to give medicines or IV fluids. It may also be hooked up to a monitor to take pressure readings. This information helps caregivers check your heart.
  
• Echocardiogram: 
  
  • This test is also called an echo. It is a type of ultrasound, using sound waves to show pictures of the size and shape of your heart. An echo also looks at how your heart moves when it is beating. These pictures are seen on a TV-like screen.
    
  • This test is done while lying down on your back. Clear jelly will be placed on your chest to help the ultrasound sensor slide easily. The sensor will be rubbed across your chest to see your heart from different angles. You may hear a whooshing noise, which is the sound of your blood flow. Caregivers may ask you to pedal a bike during the test (exercise echo) or you may get medicine before the test to increase blood flow to your heart muscle (stress echo). This test can tell how well your heart is pumping. An echo can also find problems, such as fluid around the heart or problems with your heart valves.
    
• Heart monitor: This is also called an ECG, electrocardiogram, or telemetry. Sticky pads are placed on your chest or different parts of your body. Each pad has a wire leading to a small portable box (telemetry unit), or to a TV-type screen. This lets caregivers see a tracing of the electrical activity of your heart. The heart monitor may help caregivers see problems with the way your heart is beating. Do not remove any wires or sticky pads without asking your caregiver first.
  
• Intake and output: Your caregivers may need to know the amount of liquid you are getting. They may also need to know how much you are urinating. Men 19 years old and older should drink about 3.0 Liters of liquid each day (close to 13 eight-ounce cups). Women 19 years old and older should drink about 2.2 Liters of liquid each day (close to 9 eight-ounce cups). Certain foods also contain liquid. You may need more or less liquid each day. Ask your caregiver how much liquid you should have each day. Ask caregivers if they need to measure or collect your urine before you dispose of it.
  
• Pulmonary artery line: A pulmonary artery line, or PA cath, is a kind of central line catheter. It is a thin tube put in a vein near your collarbone, or in your neck or groin. The tube is then guided through your heart and into a blood vessel that goes to your lungs. One end of this catheter is hooked to a machine called a monitor. The monitor shows numbers that tell caregivers how your heart and lungs are doing. The part of this catheter that is inside you may be used to give you medicine. You will need a chest x-ray after the PA line is placed, to be sure the line is where your caregiver wants it. You may have stitches on your skin where the line comes out. This holds the line in place.
  
• Pulse oximeter: A pulse oximeter is a machine that tells how much oxygen is in your blood. A cord with a clip or sticky strip is placed on your ear, finger, or toe. The other end of the cord is hooked to a machine. Caregivers use this machine to see if you need more oxygen.
  
• 12-lead ECG: This test, also called an EKG, helps caregivers look for damage or problems in different areas of the heart. Caregivers may need to prepare your skin by shaving off some hair, or cleaning it with a gritty lotion. Sticky pads are placed on your chest, arms, and legs. Each sticky pad has a wire that is hooked to a machine or TV-type screen. A short period of electrical activity in your heart muscle is recorded. Caregivers will look closely for certain problems or changes in how your heart is working. This test takes about 5 to 10 minutes. It is important that you lie as still as possible during the test. You may need this test more than once.
  
• Exercise stress test: This test helps caregivers see the changes that take place in your heart during exercise. It checks for blockages in the arteries of your heart. An EKG is done while you ride an exercise bike or walk on a treadmill. Caregivers will ask you how you are feeling during the test. They want to know if you have chest pain or trouble breathing.
  
• Medicine stress test: This is a test that does not use exercise but still lets caregivers see heart changes. You are given medicine in your IV that makes your heart beat faster and opens heart arteries. An EKG is taken at the same time. Be sure to tell your caregiver how you are feeling during the test.
  
• Urine sample: A sample of your urine is collected and sent to a lab for tests. Your caregiver may give you a special wipe and clean cup. Use the wipe to clean your skin around the opening you urinate from. Urinate into the clean cup. Put the lid on the cup. Do not touch the inside of the cup or lid. Give the urine sample to your caregiver.
  
• Vital signs: This includes taking your temperature, blood pressure, pulse (counting your heartbeat), and respirations (counting your breaths). To take your blood pressure, a cuff is put on your arm and tightened. The cuff is attached to a machine which gives your blood pressure reading. Caregivers may listen to your heart and lungs by using a stethoscope. Your vital signs are taken so caregivers can see how you are doing.

Treatment options: Your treatment may change if your health problem is not being controlled. This is often decided after you have tests. You may have some of the following treatments alone or together.

• Oxygen: You may need to get oxygen through a plastic mask or nasal cannula. A nasal cannula is a pair of short, thin tubes that are placed inside your nose. Tell your caregiver if the mask or prongs bother you, or if your nose gets dry. Ask your caregiver before taking off your oxygen mask, or removing your nasal cannula.
  
• IV: An IV (intravenous) is a tube placed in your vein that is used to give you medicine or liquids.
  
• Pressure stockings: These tight elastic stockings help to keep blood from staying in the legs and causing clots.
  
• 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.  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.
  
• Emergency treatment:
  
  • A life-threatening problem that may happen during and after an MI is called arrhythmias. Arrhythmias are irregular heartbeats or heart rhythms. Arrhythmias that happen due to an MI can cause sudden death. Your caregivers will watch your heart monitor 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 give 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.
    
• Intra-aortic balloon pump: An intra-aortic balloon pump, or IABP, is a long catheter that is inserted into your groin. It has a balloon on the end that rests just outside of your heart. This balloon inflates and deflates in time with your heartbeat. An IABP can help increase blood flow through your body, while decreasing how hard your heart has to work. It may also help increase blood flow to the heart muscle itself. You will need to stay in bed with your leg straight while you have an IABP.
  
• Temporary pacemaker:
  • This is a machine that helps your heart beat at a normal speed and in a regular rhythm. A temporary pacemaker may use large patches placed on your chest and back. These are connected to a special monitor. Sometimes, your caregiver may need to put small wires through your skin and into your heart muscle instead. The wires may then be connected to a small pacemaker box outside of your body.
    
  • The temporary pacemaker "reads" what your heart is doing. If your heart is beating in a different way than it should, the pacemaker takes over and controls your heartbeat. It does this by sending small electric signals to the heart muscle. This tells your heart when to beat. You may feel these signals, especially if your temporary pacemaker uses large patches on the skin. If this causes pain, use your call light and tell your caregiver. Do not get out of bed without first asking your caregiver if it is OK. You may need a pacemaker just for a short time. In some cases, you may need it for the rest of your life. If so, your caregiver may replace your temporary pacemaker with a permanent one.
    
• Permanent pacemaker:
  
  • A permanent pacemaker is a small device that helps control your heart rate. A permanent pacemaker is about the size of a wristwatch, and is implanted under your skin. You may need a pacemaker to slow your heartbeat down, speed it up, or make it more regular.
    
  • A pacemaker is made up of leads and a generator (battery). Getting a pacemaker involves having a procedure done. Most pacemakers work only when they are needed. These are called demand pacemakers. Other pacemakers work all the time. Your caregiver will decide which pacemaker is right for you.
    
• Implanted cardioverter defibrillator:
  • An implanted cardioverter defibrillator is also called an ICD. It is a small device that monitors your heart rate and rhythm. If your ICD senses that your heart is beating in an unhealthy rhythm, it will give your heart a small electrical shock. This helps your heart start beating normally again.
    
  • An ICD is made up of a generator and leads (thin, flexible wires that attach to your heart). The generator and the leads will be placed inside you during a procedure. The generator has a metal shell with a battery and a small computer inside.

Recovery:

• Cardiac rehabilitation: Cardiac rehabilitation, or cardiac rehab, is a program that helps you feel better after having a heart problem. Cardiac rehab may also decrease your risk of having heart problems in the future. During cardiac rehab, you learn how to live a more heart-healthy lifestyle. You may also learn how to exercise safely to strengthen your muscles and heart.

Medicines:

• Antinausea medicine: This medicine may be given to calm your stomach and control vomiting (throwing up).
  
• Aspirin: This is medicine that may be given to help thin the blood to keep blood clots from forming.
  
• Blood pressure medicine: This medicine may be given to lower your blood pressure. Keeping your blood pressure under control protects your heart, lungs, brain, kidneys, and other organs.
  
• Blood thinners: This medicine helps stop clots from forming in the blood. Clots can cause strokes, heart attacks, and death. Blood thinners may make it easier to bleed or bruise. While taking this medicine, use a soft toothbrush to prevent bleeding gums. If you shave, use an electric shaver.
  
• Diuretics: This medicine is often called water pills. Diuretics help your body get rid of extra fluid (edema) in your legs and ankles. This medicine may also help get rid of extra fluid in your lungs or around your heart. It may also decrease your blood pressure. You may urinate more often when taking diuretics.
  
• Cholesterol medicine: This type of medicine is given to help decrease (lower) the amount of cholesterol (fat) in your blood.
  
• 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.
  
• Heart medicine: This medicine may be given to make your heart beat stronger or more regularly. There are many different kinds of heart medicines. Talk with your caregiver to find out what your medicine is and why you are taking it.
  
• 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.
  
• Pain medicine: Caregivers may give you medicine to take away or decrease your pain. Tell caregivers right away if you start feeling discomfort, pressure, burning, or tightness in your chest. Tell caregivers right away if you start sweating, have trouble breathing, or feel discomfort in your arm, back, neck, or jaw. Any of these may be a sign that your heart is not getting enough oxygen, and may need medicine to help.