| What is a heart attack? |
A heart attack is injury to heart muscle due to a loss of blood supply. It usually occurs when a blood clot blocks the flow of blood through a coronary artery a blood vessel that feeds blood to a part of the heart muscle. Interrupted blood flow to your heart can damage or destroy a part of the heart muscle. It can also be fatal.
Each year more than a million Americans experience a heart attack. Years ago, a heart attack was often fatal. But today, thanks to better awareness of signs and symptoms and improved treatments, the vast majority of people who have a heart attack survive.
Your overall lifestyle what you eat, how often you exercise and the way you deal with stress plays a role in how well you recover from a heart attack. In addition, a healthy lifestyle can help you prevent a first or subsequent heart attack by controlling risk factors that contribute to the narrowing of arteries to your heart.
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| Signs and symptoms |
Heart attacks have many variable signs and symptoms. Not all people who have heart attacks experience the same ones or experience them to the same degree.
For example, heart attack symptoms in women, in older adults and in people with diabetes tend to be less pronounced. Some people have no symptoms at all. Still, the more signs and symptoms you have, the higher the likelihood that you may be experiencing a heart attack.
Warning signs and symptoms of a heart attack include:
- Pressure, fullness or a squeezing pain in the center of your chest that lasts for more than a few minutes
- Pain extending beyond your chest to the shoulder, arm, back, or even to your teeth and jaw
- Increasing episodes of chest pain
- Prolonged pain in the upper abdomen
- Shortness of breath
- Sweating
- Impending sense of doom
- Lightheadedness
- Fainting
- Nausea and vomiting
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| Causes |
Your heart a muscular pump in your chest beats approximately once a second. During a day, your heart pumps about 2,000 gallons of blood through your circulatory system.
Your circulatory system includes arteries and veins. Veins bring oxygen-poor blood back to your heart. Arteries deliver oxygen-rich blood to all of the tissues of your body including your heart muscle.
A heart attack occurs when one or more of the tiny arteries supplying your heart with oxygen-rich blood (coronary arteries) become blocked. These arteries are called coronary arteries because they encircle the top portion of your heart like a crown. Blockage is usually due to a blood clot that forms suddenly where a coronary artery has narrowed over the years by a buildup of cholesterol and other deposits.
This buildup of cholesterol and other deposits collectively known as plaques in arteries throughout the body is called atherosclerosis. When the coronary arteries narrow due to atherosclerosis, the condition is known as coronary artery disease.
Coronary artery disease is a major underlying cause of heart attacks. Factors that increase your risk of narrowed coronary arteries and, thus, a heart attack include family history of heart disease, a high level of low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol), high blood pressure, smoking, obesity and physical inactivity.
Rarely, a heart attack can occur when a blood clot from inside a diseased heart breaks loose and lodges in a healthy or narrowed coronary artery. Another uncommon cause of a heart attack is a spasm of a coronary artery that shuts down blood flow to part of the heart muscle. Drugs such as cocaine can cause such a life-threatening spasm.
The technical term for a heart attack is myocardial infarction. Myo refers to "muscle;" cardio refers to "heart;" infarct refers to "death of tissue from lack of oxygen." Like any muscle, the heart needs a steady supply of blood, or the tissue will be damaged or begin to die. Without blood, heart cells are injured, causing pain or pressure. If blood flow isn't restored, heart cells can die and scar tissue can form, replacing working heart tissue. If damage occurs to too great an area of heart muscle, a heart attack can be fatal.
A heart attack is not a static one-time event. It's a dynamic process that typically evolves over 4 to 6 hours. With each passing minute, more heart tissue is deprived of blood and deteriorates or dies. However, if blood flow can be restored in time, damage to the heart can be limited or prevented.
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| Risk factors |
Certain factors, called coronary risk factors, increase your risk of a heart attack. These factors contribute to the unwanted buildup of deposits (atherosclerosis) that narrows arteries throughout your body, including arteries to your heart. Coronary risk factors include:
- High blood pressure. Blood pressure is determined by the amount of blood your heart pumps and the amount or resistance to blood flow in your arteries. Over time, high blood pressure 140/90 millimeters of mercury (mm Hg) or higher can damage arteries that feed your heart by accelerating atherosclerosis. High blood pressure can be an inherited problem. The risk of high blood pressure increases as you age. But the main culprit for most Americans is eating a diet too high in salt and being overweight.
- High blood cholesterol levels. Cholesterol is a large part of the deposits that can narrow arteries throughout your body, including those that feed your heart. A high level of the wrong kind of cholesterol in your blood increases your risk of a heart attack. Low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol) is most likely to narrow arteries. A high LDL level is undesirable and is a byproduct of a diet high in saturated fats and cholesterol. A high level of triglycerides, a type of blood fat related to your diet, also is undesirable. However, a high level of high-density lipoprotein (HDL) cholesterol (the "good" cholesterol), which helps the body clean up excess cholesterol, is desirable and lowers your risk of heart attack.
- Cigarette smoke. Smoking and long-term exposure to secondhand smoke damage the interior walls of arteries including arteries to your heart allowing deposits of cholesterol to collect and hamper the flow of blood. Cigarette smoke also increases the risk of deadly blood clots forming and causing a heart attack.
- Lack of physical activity. An inactive lifestyle contributes to high blood cholesterol levels and obesity. Conversely, people who get regular aerobic exercise have better cardiovascular fitness, which decreases their overall risk of heart attack. Exercise is also beneficial in lowering high blood pressure.
- Obesity. Obesity involves having a high proportion of body fat. Obesity raises the risk of heart disease because it's associated with high blood cholesterol levels, high blood pressure and diabetes.
- Diabetes. Diabetes is the inability of the body to produce or respond to insulin properly. Insulin, a hormone secreted by your pancreas, allows your body to use glucose, which is a form of sugar from foods. Diabetes can occur in childhood, but it appears more often in middle age and among overweight people. Diabetes greatly increases the risk of a heart attack by speeding up atherosclerosis and negatively affecting blood cholesterol levels.
- Stress. You may respond to stress in ways that can increase your risk of a heart attack. If you're under stress, you may overeat or smoke from nervous tension. Too much stress, as well as anger, can also raise your blood pressure.
- Alcohol. Consumed in moderation, alcohol helps raise HDL levels the "good" cholesterol and can have a protective effect against heart attack. However, excessive drinking can raise your blood pressure and triglyceride levels, increasing your risk of heart attack.
- Family history of heart attack. If your siblings, parents or grandparents have had early heart attacks, you may be at risk, too. Your family may have a genetic condition that raises unwanted blood cholesterol levels. High blood pressure also can run in families. In addition, families may contribute to coronary artery disease by practicing or promoting poor health habits such as smoking or eating high-fat diets.
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| When to seek medical advice |
During a heart attack, many people waste precious minutes because they don't recognize signs and symptoms or they deny them. Many people also delay calling for help because they're afraid to risk the embarrassment of a false alarm.
However, one of the most important things you can do to survive a heart attack is to recognize what's happening and to take immediate action. Of the people who die of heart attacks, most die within the first hour after the onset of signs and symptoms. Don't waste time minutes matter!
Seek emergency medical treatment if you think you or another person may be experiencing a heart attack. An ambulance crew can begin treatment, and the sooner you get to a hospital, the more that can be done to limit the amount of damage done to your heart during a heart attack. Fast action could save your life.
| Screening and diagnosis |
Ideally, your doctor should screen you during regular physical exams for risk factors that can lead to a heart attack.
If you're having a heart attack or suspect you're having one, screening and diagnosis will likely happen in another setting an emergency room. Once there, you'll probably be asked to describe your symptoms and will have your blood pressure, pulse and temperature checked. Your doctor will listen to your heart and lung sounds with a stethoscope. You'll be asked about your health history and the history of heart disease in your family. Emergency room doctors may also want to conduct tests to determine whether your signs and symptoms, such as chest pain, signal a heart attack or another condition. These tests may include:
- Electrocardiogram (ECG). This is often the first test done to diagnose a heart attack. This test records the electrical activity of your heart, which controls your heartbeat, through electrodes attached to your skin. Impulses are recorded as "waves" displayed on a monitor or printed on paper. Because injured heart muscle doesn't conduct electrical impulses normally, the ECG may show that a heart attack has occurred or is in progress.
- Blood tests. Certain heart enzymes slowly leak out into your blood if your heart has been damaged by a heart attack. Emergency room doctors may take samples of your blood to test for the presence of these enzymes.
- Chest X-ray. An X-ray image of your chest allows your doctor to check the size and shape of your heart and its blood vessels.
- Nuclear scan. This test helps identify blood flow problems to your heart. Trace amounts of radioactive material, such as thallium, are injected into your bloodstream. Special cameras can detect the radioactive material as it flows through your heart and lungs. Areas of blockage in arteries through which less of the radioactive material flows appear as dark spots on the scan.
- Echocardiogram. This test uses sound waves to produce an image of your heart. In an echocardiogram, sound waves are directed at your heart from a wand-like device (transducer) held on your chest. The sound waves bounce off your heart and are reflected back through your chest wall and processed electronically to provide video images of your heart. An echocardiogram can help identify whether an area of your heart has been damaged by a heart attack and isn't pumping normally or at peak capacity.
- Coronary catheterization (angiogram). This test can show if your coronary arteries are narrowed or blocked. A liquid dye is injected into the arteries of your heart through a long, thin tube (catheter) that's fed through an artery, usually in your leg, to arteries in your heart. As the dye fills your arteries, the arteries become visible on X-ray and videotape, revealing areas of blockage. Additionally, while the catheter is in position, it can be used to treat the blockage. This procedure, called angioplasty, is discussed below.
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| Complications |
At the very least, a heart attack can cause pain and discomfort. At the very most, a heart attack can cause death. Complications are often related to the damage sustained by your heart during a heart attack. This damage can lead to the following conditions:
- Abnormal heart rhythms (arrhythmias). If your heart muscle is damaged from a heart attack, electrical "short circuits" can develop resulting in abnormal heart rhythms, some of which can be serious and require treatment.
- Congestive heart failure. The amount of damaged tissue in your heart may be so extensive that the remaining heart muscle can't do an adequate job of pumping blood out of your heart. This decreases blood flow to tissues and organs throughout your body, producing shortness of breath, fatigue, and swelling in your ankles and feet. Congestive heart failure may be a temporary problem that remedies itself after a heart stunned by a heart attack recovers over a few days to weeks. However, it can also be a chronic condition resulting from significant and permanent damage to a heart following a heart attack.
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| Treatment |
During a heart attack, act immediately. Take these steps:
- Call for emergency medical help. The 911 dispatcher contacts the emergency medical services (EMS) system. In areas without 911, call your emergency medical response system. It's usually better to call these emergency numbers first. Calling your doctor may add unnecessary time. If you think you're having a heart attack, never drive yourself to the hospital. EMS responders should reach you within 4 to 5 minutes. When you call emergency assistance, describe your signs and symptoms, such as severe shortness of breath or chest pain. This ensures a priority dispatch of EMS responders trained in basic and advanced cardiac life support.
- Chew aspirin. Aspirin inhibits blood clotting, which helps maintain blood flow through a narrowed artery. If you think you're having a heart attack, take one regular strength aspirin and chew it to speed absorption. When taken during a heart attack, aspirin can decrease death rates by 25 percent.
In the initial minutes, a heart attack can also trigger ventricular fibrillation. This unstable heart rhythm produces an ineffective heartbeat, and the heart quivers uselessly. Without immediate treatment, ventricular fibrillation leads to sudden death. The wide use of automatic external defibrillators (AEDs) that shock the heart back into a normal rhythm can provide emergency treatment before a person suffering a heart attack reaches the hospital.
Most ambulance teams carry portable defibrillators. Many police and fire rescue units also carry defibrillators and may respond before an ambulance. AEDs are easy to operate and are also increasingly available in commercial airplanes and public places.
Once you reach a hospital emergency room and it's clear you're having a heart attack, you may be treated with medications, undergo a surgical procedure or both depending on the severity of your condition and the amount of damage your heart may have sustained.
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Medications
With each passing minute of a heart attack, more tissue is deprived of oxygen and deteriorates or dies. The main way to prevent progressive damage is to restore blood flow quickly. Doctors may give you aspirin in the emergency room. Aspirin inhibits blood clotting, which helps maintain blood flow through a narrowed artery. But, again, if you think you're having a heart attack, take one regular strength aspirin and chew it to speed absorption on your way to the emergency room.
Initial treatment of a heart attack in the emergency room may also involve prescription medications, typically given through a vein in your arm (intravenously), such as:
- Thrombolytics. These drugs, also called clot-busters, help dissolve a blood clot that's blocking a coronary artery and blood flow to your heart. The earlier you receive a thrombolytic drug following a heart attack, the greater the chance you will survive and lessen the damage to your heart.
- "Super aspirins." Doctors in the emergency room may give you a thrombolytic drug along with a second drug called a platelet IIb/IIIa receptor blocker, or "super aspirin." The second drug, which is more potent than regular aspirin, helps prevent new clots from forming. This "one-two punch" combination may cancel out the need for further treatments.
- Other blood-thinning medications. These drugs, such as heparin or hirudin, like aspirins, make your blood less "sticky" and less likely to form more dangerous clots.
- Pain relievers. If your chest pain or associated pain is great, you may receive a pain reliever such as morphine to relieve your discomfort.
- Nitroglycerine. This medication, used to treat chest pain (angina), emporarily opens narrowed blood vessels, improving blood flow to and from your heart.
- Beta blockers. These medications help relax your heart muscle, slow your heartbeat and decrease blood pressure, making your heart's job easier.
- Cholesterol-lowering medications. Examples include statins, niacin, fibrates and bile acid sequestrants. These drugs help lower levels of unwanted blood cholesterol and may be helpful if given early after a heart attack to improve survival.
Surgical and other procedures
In addition to medications, you may undergo one of the following procedures to treat a heart attack:
- Coronary angioplasty. Emergency angioplasty, a procedure available at large medical centers, opens blocked coronary arteries, letting blood flow more freely to your heart. Doctors insert a long, thin tube (catheter) that's passed through an artery, usually in your leg, to a blocked artery in your heart. This catheter is equipped with a special balloon tip. Once in position, the balloon tip is briefly inflated to open up a blocked coronary artery. At the same time, a metal mesh (stent) may be inserted into the artery to keep it open long-term, restoring blood flow to the heart. Coronary angioplasty may be done at the same time as a coronary catheterization (angiogram), a similar procedure that doctors do first to locate narrowed arteries to the heart.
- Coronary artery bypass surgery. In rare cases, doctors may perform emergency bypass surgery at the time of a heart attack. Bypass surgery involves sewing veins or arteries in place at a site beyond a blocked or narrowed coronary artery (bypassing the narrowed section), restoring blood flow to the heart. Your doctor may suggest that you have this procedure after your heart has had time to recover from a heart attack.
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Rehabilitation
The goal of emergency treatment of a heart attack is to restore blood flow and save heart tissue. The purpose of subsequent treatment is to promote healing of your heart and prevent another heart attack.
Cardiac rehabilitation programs begin while you're in the hospital and, depending on the severity of your attack, continue for weeks to months after you return home. Cardiac rehabilitation programs generally focus on three main areas medications, lifestyle changes and emotional issues.
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| Prevention |
It's never too late to take steps to prevent a heart attack even if you've already had one before. Drug therapy has become an increasingly important part of reducing the risk of a second heart attack and helping a damaged heart function better. Lifestyle factors also play a critical role in heart attack prevention and recovery.
Medications
Doctors typically prescribe drug therapy for people who've had a heart attack or who are at high risk of having one. Medications that help the heart function more effectively or reduce heart attack risk may include:
- Blood-thinning medications. Aspirin makes your blood less "sticky" and likely to clot. Doctors recommend a daily aspirin for most people who've had a heart attack. Your doctor may, in some cases, prescribe a stronger blood thinner than aspirin.
Doctors may prescribe aspirin and an anticlotting drug such as clopidogrel (Plavix) for people undergoing an angioplasty to open narrowed coronary arteries, both before and after the procedure. Taking the drugs together before and after angioplasty appears to cut the risk of future heart attack or death from heart disease by up to one- third.
If you're taking aspirin to help prevent a heart attack, be aware that a study in the New England Journal of Medicine found that the painkiller ibuprofen (Advil, Motrin, others) may undermine aspirin's proven blood-thinning effects. Taken at the same time, ibuprofen appears to interfere with the heart benefits of aspirin. - Beta blockers. These drugs lower your heart rate and blood pressure, reducing demand on your heart. You generally need to take beta blockers for 1 year or more following a heart attack.
- Angiotensin-converting enzyme (ACE) inhibitors. Your doctor may prescribe ACE inhibitors if you've had a moderate to severe heart attack that has reduced your heart's pumping capacity. These drugs allow blood to flow from your heart more easily.
- Cholesterol-lowering medications. A variety of medications, including statins, niacin, fibrates and bile acid sequestrants, can help lower your levels of unwanted blood cholesterol. The majority of people who've had a heart attack take cholesterol-lowering medications drugs that help lower the risk of a second heart attack.
- Calcium channel blockers. These medications help relax the muscle of blood vessels. Some slow your heart rate.
How you live your life can largely affect the health of your heart. Taking the following steps can help you not only prevent but also recover from a heart attack:
- Get regular medical checkups. Some of the main risk factors for heart attack high blood cholesterol, high blood pressure and diabetes cause no symptoms in their early stages. But your doctor can perform tests to check that you're free of these conditions. If a problem exists, you and your doctor can manage it early to prevent complications that can lead to a heart attack.
- Control your blood pressure. Have your blood pressure checked every 2 years. Your doctor may recommend more frequent measurement if you have high blood pressure or a history of coronary artery disease. Optimal blood pressure with respect to cardiovascular risk is 120/80 mm Hg.
- Check your cholesterol. Have your blood cholesterol levels checked regularly, through a blood test at your doctor's office. If "bad" cholesterol levels are undesirably high, your doctor can prescribe changes to your diet and medications to help lower the numbers and protect your cardiovascular health.
In addition to standard cholesterol blood work-up, your doctor may order a cholesterol screening called the C-reactive protein (CRP) blood test. This test measures the level of C-reactive protein in your blood. Too much of this protein in your bloodstream indicates inflammation of the arteries a potential precursor to a heart attack. - Don't smoke. If you smoke, the single most important thing you can do before or after having a heart attack is to stop. Continuing to smoke doubles your risk of a second heart attack or heart-related death. If you can't stop smoking by yourself, ask your doctor to prescribe a treatment plan to help you kick the habit.
- Exercise regularly. Years ago, doctors forbid exercise following a heart attack for fear it would cause another. But regular exercise helps improve heart muscle function following a heart attack. Exercise is now a major component of a cardiac rehabilitation program. Exercise helps prevent a heart attack by helping you to achieve and maintain a healthy weight and control diabetes, elevated cholesterol and high blood pressure.
- Maintain a healthy weight. Being only 10 percent overweight increases your risk of coronary artery disease. Losing just 5 to 10 pounds may lower your blood pressure.
- Eat a heart-healthy diet. Too much fat and cholesterol in your diet can narrow arteries to your heart. If you've had a heart attack, limit fat and cholesterol and sodium. A diet high in salt can raise your blood pressure. Follow your doctor's and dietitian's advice on eating a heart-healthy diet. Prepare heart-healthy meals together as a family. Fish is part of a heart-healthy diet. It contains omega-3 fatty acids, which help improve blood cholesterol levels and prevent blood clots. Eat plenty of fruits and vegetables. Fruits and vegetables contain antioxidants nutrients that help prevent everyday wear and tear on your coronary arteries.
- Ensure adequate folic acid. Adequate folic acid may reduce the amount of homocysteine, an amino acid that builds and maintains tissues, in your blood. Too much homocysteine may promote atherosclerosis. Folic acid is plentiful in green, leafy vegetables, citrus fruits and whole grains.
- Manage stress. To reduce your risk of a heart attack, reduce stress in your day-to-day activities. Rethink workaholic habits and find healthy ways to minimize or deal with stressful events in your life.
- Consume alcohol in moderation. Drinking more than two alcoholic drinks a day raises blood pressure, so cut back on your drinking if necessary.
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| Coping skills |
Having a heart attack is a scary experience. Even if your doctor says you're OK, you may still be scared. How will this affect your life? Will you be able to get back to work or resume activities you enjoy? Even more frightening will it happen again?
Fear is just one of the many emotions you and your family must deal with. Other emotions that can be particularly difficult to cope with after a heart attack may include:
- Anger. You may be angry and wonder: "Why did I have to have a heart attack, and why now?" It's normal to feel some resentment after a heart attack.
- Guilt. Family members may feel scared at first and then guilty about your heart attack. Some may even feel that they're somehow responsible for doing something that gave you a heart attack.
- Depression. Depression is common after a heart attack. You may feel that you can no longer do things you used to do that you're not the same person you were before the heart attack.
Many people worry that sex after a heart attack will be too strenuous on their heart. However, most people can safely return to sexual activity by the second week after a heart attack or heart operation. Each person has a different timeline, depending on his or her level of physical comfort, psychological readiness and previous sexual activity.
The demands sexual intercourse places on your heart approximate those of taking a brisk walk, scrubbing a floor, or climbing one or two flights of stairs. In a way, sexual activity parallels any other physical exertion your heart rate, breathing rate and blood pressure level increase. So proceed sensibly, with caution but without fear. As your confidence in the health of your heart grows, you'll likely be able to resume your normal sexual patterns.
Some heart medications, such as beta blockers, may affect sexual function. However, sexual dysfunction following a heart attack is more often due to depression or anxiety than to medications. If you're having problems with sexual dysfunction, talk to your doctor. He or she may be able to help you pinpoint the problem and seek the appropriate treatment.
You and your family may have a lot of questions and concerns following your heart attack. If so, it might be helpful to talk to others who are experiencing some of the same things as you and your family. Many cardiac rehabilitation programs offer counseling services and support groups for heart attack survivors.
Surviving a heart attack doesn't mean that life as you know it is over. On the contrary, most people lead full, active lives after a heart attack. But it may mean making some positive changes in your daily habits, being patient as you recover and adopting a can-do attitude.
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May 15, 2003

