Heart attacks are a leading killer of both men and women in the United States. The good news is that excellent treatments are available for heart attacks. These treatments can save lives and prevent disabilities.
What Is a Heart Attack?
A heart attack happens when the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart can't get oxygen. If blood flow isn't restored quickly, the section of heart muscle begins to die.
Heart attacks are a leading killer of both men and women in the United States. The good news is that excellent treatments are available for heart attacks. These treatments can save lives and prevent disabilities.
Heart attack treatment works best when it's given right after symptoms occur. If you think you or someone else is having a heart attack (even if you're not fully sure), call9–1–1 right away.
Heart attacks most often occur as a result of coronary heart disease (CHD), also called coronary artery disease. CHD is a condition in which a waxy substance called plaque (plak) builds up inside the coronary arteries. These arteries supply oxygen-rich blood to your heart.
When plaque builds up in the arteries, the condition is called atherosclerosis (ath-er-o-skler-O-sis). The buildup of plaque occurs over many years.
Eventually, an area of plaque can rupture (break open) inside of an artery. This causes a blood clot to form on the plaque's surface. If the clot becomes large enough, it can mostly or completely block blood flow through a coronary artery.
If the blockage isn't treated quickly, the portion of heart muscle fed by the artery begins to die. Healthy heart tissue is replaced with scar tissue. This heart damage may not be obvious, or it may cause severe or long-lasting problems.
Figure A shows a heart with dead heart muscle caused by a heart attack. Figure B is a cross-section of a coronary artery with plaque buildup and a blood clot.
A less common cause of heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery. Spasms can occur in coronary arteries that aren't affected by atherosclerosis.
Heart attacks can be associated with or lead to severe health problems, such as heart failure and life-threatening arrhythmias (ah-RITH-me-ahs).
Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Arrhythmias are irregular heartbeats. Ventricular fibrillation is a life-threatening arrhythmia that can cause death if not treated right away.
Acting fast at the first sign of heart attack symptoms can save your life and limit damage to your heart. Treatment works best when it's given right after symptoms occur.
Many people aren't sure what's wrong when they are having symptoms of a heart attack. Some of the most common warning symptoms of a heart attack for both men and women are:
Other possible symptoms of a heart attack include:
Not all heart attacks begin with the sudden, crushing chest pain that often is shown on TV or in the movies, or other common symptoms such as chest discomfort. The symptoms of a heart attack can vary from person to person. Some people can have few symptoms and are surprised to learn they've had a heart attack. If you've already had a heart attack, your symptoms may not be the same for another one.
Quick Action Can Save Your Life: Call 9–1–1
If you think you or someone else may be having heart attack symptoms or a heart attack, don't ignore it or feel embarrassed to call for help. Call 9–1–1 for emergency medical care. Acting fast can save your life.
Do not drive to the hospital or let someone else drive you. Call an ambulance so that medical personnel can begin life-saving treatment on the way to the emergency room. Take a nitroglycerin pill if your doctor has prescribed this type of treatment.
Each year, close to 1 million people in the United States have heart attacks, and many of them die. CHD, which often results in heart attacks, is the leading killer of both men and women in the United States.
Many more people could survive or recover better from heart attacks if they got help faster. Of the people who die from heart attacks, about half die within an hour of the first symptoms and before they reach the hospital.
A heart attack happens if the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart can't get oxygen. Most heart attacks occur as a result of coronary heart disease (CHD).
CHD is a condition in which a waxy substance called plaque builds up inside of the coronary arteries. These arteries supply oxygen-rich blood to your heart.
When plaque builds up in the arteries, the condition is called atherosclerosis. The buildup of plaque occurs over many years.
Eventually, an area of plaque can rupture (break open) inside of an artery. This causes a blood clot to form on the plaque's surface. If the clot becomes large enough, it can mostly or completely block blood flow through a coronary artery.
If the blockage isn't treated quickly, the portion of heart muscle fed by the artery begins to die. Healthy heart tissue is replaced with scar tissue. This heart damage may not be obvious, or it may cause severe or long-lasting problems.
A less common cause of heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery. Spasms can occur in coronary arteries that aren't affected by atherosclerosis.
What causes a coronary artery to spasm isn't always clear. A spasm may be related to:
The animation below shows how plaque buildup or a coronary artery spasm can lead to a heart attack. Click the "start" button to play the animation. Written and spoken explanations are provided with each frame. Use the buttons in the lower right corner to pause, restart, or replay the animation, or use the scroll bar below the buttons to move through the frames.
Certain risk factors make it more likely that you'll develop coronary heart disease (CHD) and have a heart attack. You can control many of these risk factors.
The major risk factors for a heart attack that you can control include:
Some of these risk factors—such as obesity, high blood pressure, and high blood sugar—tend to occur together. When they do, it's called metabolic syndrome.
In general, a person who has metabolic syndrome is twice as likely to develop heart disease and five times as likely to develop diabetes as someone who doesn't have metabolic syndrome.
For more information about the risk factors that are part of metabolic syndrome, go to the Health Topics Metabolic Syndrome article.
Risk factors that you can't control include:
Not all heart attacks begin with the sudden, crushing chest pain that often is shown on TV or in the movies. In one study, for example, one-third of the patients who had heart attacks had no chest pain. These patients were more likely to be older, female, or diabetic.
The symptoms of a heart attack can vary from person to person. Some people can have few symptoms and are surprised to learn they've had a heart attack. If you've already had a heart attack, your symptoms may not be the same for another one. It is important for you to know the most common symptoms of a heart attack and also remember these facts:
Some people don't have symptoms at all. Heart attacks that occur without any symptoms or with very mild symptoms are called silent heart attacks.
The most common warning symptoms of a heart attack for both men and women are:
The symptoms of angina (an-JI-nuh or AN-juh-nuh) can be similar to the symptoms of a heart attack. Angina is chest pain that occurs in people who have coronary heart disease, usually when they're active. Angina pain usually lasts for only a few minutes and goes away with rest.
Chest pain or discomfort that doesn't go away or changes from its usual pattern (for example, occurs more often or while you're resting) can be a sign of a heart attack.
All chest pain should be checked by a doctor.
Pay attention to these other possible symptoms of a heart attack:
Not everyone having a heart attack has typical symptoms. If you've already had a heart attack, your symptoms may not be the same for another one. However, some people may have a pattern of symptoms that recur.
The more signs and symptoms you have, the more likely it is that you're having a heart attack.
The signs and symptoms of a heart attack can develop suddenly. However, they also can develop slowly—sometimes within hours, days, or weeks of a heart attack.
Any time you think you might be having heart attack symptoms or a heart attack, don't ignore it or feel embarrassed to call for help. Call 9–1–1 for emergency medical care, even if you are not sure whether you're having a heart attack. Here's why:
Every minute matters. Never delay calling 9–1–1 to take aspirin or do anything else you think might help.
Your doctor will diagnose a heart attack based on your signs and symptoms, your medical and family histories, and test results.
An EKG is a simple, painless test that detects and records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart.
An EKG can show signs of heart damage due to coronary heart disease (CHD) and signs of a previous or current heart attack.
During a heart attack, heart muscle cells die and release proteins into the bloodstream. Blood tests can measure the amount of these proteins in the bloodstream. Higher than normal levels of these proteins suggest a heart attack.
Commonly used blood tests include troponin tests, CK or CK–MB tests, and serum myoglobin tests. Blood tests often are repeated to check for changes over time.
Coronary angiography (an-jee-OG-ra-fee) is a test that uses dye and special x rays to show the insides of your coronary arteries. This test often is done during a heart attack to help find blockages in the coronary arteries.
To get the dye into your coronary arteries, your doctor will use a procedure called cardiac catheterization (KATH-e-ter-ih-ZA-shun).
A thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck. The tube is threaded into your coronary arteries, and the dye is released into your bloodstream.
Special x rays are taken while the dye is flowing through the coronary arteries. The dye lets your doctor study the flow of blood through the heart and blood vessels.
If your doctor finds a blockage, he or she may recommend a procedure calledpercutaneous (per-ku-TA-ne-us) coronary intervention (PCI), sometimes referred to as coronary angioplasty (AN-jee-oh-plas-tee). This procedure can help restore blood flow through a blocked artery. Sometimes a small mesh tube called a stent is placed in the artery to help prevent blockages after the procedure.
Early treatment for a heart attack can prevent or limit damage to the heart muscle. Acting fast, at the first symptoms of a heart attack, can save your life. Medical personnel can begin diagnosis and treatment even before you get to the hospital.
Certain treatments usually are started right away if a heart attack is suspected, even before the diagnosis is confirmed. These include:
Once the diagnosis of a heart attack is confirmed or strongly suspected, doctors start treatments to try to promptly restore blood flow to the heart. The two main treatments are "clot-busting" medicines and percutaneous coronary intervention (PCI), sometimes referred to as coronary angioplasty, a procedure used to open blocked coronary arteries.
Clot-Busting Medicines
Thrombolytic medicines, also called "clot busters," are used to dissolve blood clots that are blocking the coronary arteries. To work best, these medicines must be given within several hours of the start of heart attack symptoms. Ideally, the medicine should be given as soon as possible.
Percutaneous Coronary Intervention
Percutaneous (per-ku-TA-ne-us) coronary intervention (PCI) is a nonsurgical procedure that opens blocked or narrowed coronary arteries. This procedure also is called coronary angioplasty.
A thin, flexible tube with a balloon or other device on the end is threaded through a blood vessel, usually in the groin (upper thigh), to the narrowed or blocked coronary artery.
Once in place, the balloon is inflated to compress the plaque against the wall of the artery. This restores blood flow through the artery.
During the procedure, the doctor may put a small mesh tube called a stent in the artery. The stent helps prevent blockages in the artery in the months or years after the procedure.
For more information, go to the Health Topics PCI article.
Other Treatments for Heart Attack
Medicines
You also may be given medicines to relieve pain and anxiety, treat arrhythmias (which often occur during a heart attack), or lower your cholesterol (these medicines are called statins).
Medical Procedures
Coronary artery bypass grafting (CABG) also may be used to treat a heart attack. During CABG, a surgeon removes a healthy artery or vein from your body. The artery or vein is then connected, or grafted, to the blocked coronary artery.
The grafted artery or vein bypasses (that is, goes around) the blocked portion of the coronary artery. This provides a new route for blood to flow to the heart muscle.
For more information, go to the Health Topics Coronary Artery Bypass Graftingarticle.
Treatment After You Leave the Hospital
Most people spend several days in the hospital after a heart attack. When you leave the hospital, treatment doesn't stop. At home, your treatment may include daily medicines and cardiac rehabilitation (rehab). Your doctor may want you to have a flu shot and pneumococcal vaccine each year.
Your doctor also may recommend lifestyle changes, including following a heart healthy diet, being physically active, maintaining a healthy weight, and quitting smoking. Taking these steps can lower your chances of having another heart attack.
Cardiac Rehabilitation
Your doctor may recommend cardiac rehab to help you recover from a heart attack and to help prevent another heart attack. Almost everyone who has had a heart attack can benefit from rehab.
Cardiac rehab is a medically supervised program that may help improve the health and well-being of people who have heart problems.
The cardiac rehab team may include doctors, nurses, exercise specialists, physical and occupational therapists, dietitians or nutritionists, and psychologists or other mental health specialists.
Rehab has two parts:
Lowering your risk factors for coronary heart disease (CHD) can help you prevent a heart attack. (For more information about risk factors, go to "Who Is at Risk for a Heart Attack?")
Even if you already have CHD, you can still take steps to lower your risk for a heart attack. These steps involve following a heart healthy lifestyle and getting ongoing care.
Following a healthy diet is an important part of a heart healthy lifestyle. A healthy diet includes a variety of fruits, vegetables, and whole grains. It also includes lean meats, poultry, fish, beans, and fat-free or low-fat milk or milk products. A healthy diet is low in saturated fat, trans fat, cholesterol, sodium (salt), and added sugars.
For more information about following a healthy diet, go to the National Heart, Lung, and Blood Institute's (NHLBI's) Aim for a Healthy Weight Web site, "Your Guide to a Healthy Heart," and "Your Guide to Lowering Your Blood Pressure With DASH." All of these resources provide general information about healthy eating.
If you're overweight or obese, work with your doctor to create a reasonable weight-loss plan that involves diet and physical activity. Controlling your weight helps you control risk factors for CHD and heart attack.
Be as physically active as you can. Physical activity can improve your fitness level and your health. Talk with your doctor about what types of activity are safe for you.
For more information about physical activity, go to the Health Topics Physical Activity and Your Heart article and the NHLBI's "Your Guide to Physical Activity and Your Heart."
If you smoke, quit. Smoking can raise your risk of CHD and heart attack. Talk with your doctor about programs and products that can help you quit. Also, try to avoid secondhand smoke. For more information about quitting smoking, go to the Health Topics Smoking and Your Heart article.
Treating conditions that make a heart attack more likely also can help lower your risk for a heart attack. These conditions may include:
Make sure that you have an emergency action plan in case you or someone in your family has a heart attack. This is very important if you're at high risk for a heart attack or have already had a heart attack.
Write down a list of medicines you are taking, medicines you are allergic to, your health care provider's phone numbers (both during and after office hours), and contact information for a friend or relative. Keep the list in a handy place to share in a medical emergency (for example, fill out this wallet card).
Talk with your doctor about the signs and symptoms of a heart attack, when you should call 9–1–1, and steps you can take while waiting for medical help to arrive.
Many people survive heart attacks and live active, full lives. If you get help quickly, treatment can limit damage to your heart muscle. Less heart damage improves your chances for a better quality of life after a heart attack.
After a heart attack, you'll need treatment for coronary heart disease (CHD). This will help prevent another heart attack. Your doctor may recommend:
If you find it hard to get your medicines or take them, talk with your doctor. Don't stop taking medicines that can help you prevent another heart attack.
After a heart attack, most people who don't have chest pain or discomfort or other problems can safely return to most of their normal activities within a few weeks. Most can begin walking right away.
Sexual activity also can begin within a few weeks for most patients. Talk with your doctor about a safe schedule for returning to your normal routine.
If allowed by State law, driving usually can begin within a week for most patients who don't have chest pain or discomfort or other problems. Each State has rules about driving a motor vehicle following a serious illness. People who have complications shouldn't drive until their symptoms have been stable for a few weeks.
After a heart attack, many people worry about having another heart attack. Sometimes they feel depressed and have trouble adjusting to new lifestyle changes.
Talk about how you feel with your health care team. Talking to a professional counselor also can help. If you're very depressed, your doctor may recommend medicines or other treatments that can improve your quality of life.
Joining a patient support group may help you adjust to life after a heart attack. You can see how other people who have the same symptoms have coped with them. Talk with your doctor about local support groups or check with an area medical center.
Support from family and friends also can help relieve stress and anxiety. Let your loved ones know how you feel and what they can do to help you.
Once you've had a heart attack, you're at higher risk for another one. Knowing the difference between angina and a heart attack is important. Angina is chest pain that occurs in people who have CHD.
The pain from angina usually occurs after physical exertion and goes away in a few minutes when you rest or take medicine as directed.
The pain from a heart attack usually is more severe than the pain from angina. Heart attack pain doesn't go away when you rest or take medicine.
If you don't know whether your chest pain is angina or a heart attack, call 9–1–1.
The symptoms of a second heart attack may not be the same as those of a first heart attack. Don't take a chance if you're in doubt. Always call 9–1–1 right away if you or someone else has heart attack symptoms.
Unfortunately, most heart attack victims wait 2 hours or more after their symptoms start before they seek medical help. This delay can result in lasting heart damage or death.
The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.
NHLBI-supported research has led to many advances in medical knowledge and care. For example, this research has uncovered some of the causes of heart diseases and conditions, as well as ways to prevent or treat them.
Many more questions remain about heart diseases and conditions, including heart attacks. The NHLBI continues to support research aimed at learning more about heart attacks. For example, NHLBI-supported research includes studies that explore:
Much of this research depends on the willingness of volunteers to take part in clinical trials. Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions.
For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.
By taking part in a clinical trial, you can gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.
If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.
If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.
For more information about clinical trials related to heart attacks, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:
PDF: About Heart Attack
Source: NHLBI, NIH
Most people who have SCA die from it—often within minutes. Rapid treatment of SCA with a defibrillator can be lifesaving. A defibrillator is a device that sends an electric shock to the heart to try to restore its normal rhythm.
Sudden cardiac arrest (SCA) is a condition in which the heart suddenly and unexpectedly stops beating. If this happens, blood stops flowing to the brain and other vital organs.
SCA usually causes death if it's not treated within minutes.
To understand SCA, it helps to understand how the heart works. The heart has an electrical system that controls the rate and rhythm of the heartbeat. Problems with the heart's electrical system can cause irregular heartbeats called arrhythmias.
There are many types of arrhythmias. During an arrhythmia, the heart can beat too fast, too slow, or with an irregular rhythm. Some arrhythmias can cause the heart to stop pumping blood to the body—these arrhythmias cause SCA.
SCA is not the same as a heart attack. A heart attack occurs if blood flow to part of the heart muscle is blocked. During a heart attack, the heart usually doesn't suddenly stop beating. SCA, however, may happen after or during recovery from a heart attack.
People who have heart disease are at higher risk for SCA. However, SCA can happen in people who appear healthy and have no known heart disease or other risk factors for SCA.
Most people who have SCA die from it—often within minutes. Rapid treatment of SCA with a defibrillator can be lifesaving. A defibrillator is a device that sends an electric shock to the heart to try to restore its normal rhythm.
Automated external defibrillators (AEDs) can be used by bystanders to save the lives of people who are having SCA. These portable devices often are found in public places, such as shopping malls, golf courses, businesses, airports, airplanes, casinos, convention centers, hotels, sports venues, and schools.
Ventricular fibrillation (v-fib) causes most sudden cardiac arrests (SCAs). V-fib is a type of arrhythmia.
During v-fib, the ventricles (the heart's lower chambers) don't beat normally. Instead, they quiver very rapidly and irregularly. When this happens, the heart pumps little or no blood to the body. V-fib is fatal if not treated within a few minutes.
Other problems with the heart's electrical system also can cause SCA. For example, SCA can occur if the rate of the heart's electrical signals becomes very slow and stops. SCA also can occur if the heart muscle doesn't respond to the heart's electrical signals.
Certain diseases and conditions can cause the electrical problems that lead to SCA. Examples include coronary heart disease(CHD), also called coronary artery disease; severe physical stress; certain inherited disorders; and structural changes in the heart.
Several research studies are under way to try to find the exact causes of SCA and how to prevent them.
CHD is a disease in which a waxy substance called plaque (plak) builds up in the coronary arteries. These arteries supply oxygen-rich blood to your heart muscle.
Plaque narrows the arteries and reduces blood flow to your heart muscle. Eventually, an area of plaque can rupture (break open). This may cause a blood clot to form on the plaque's surface.
A blood clot can partly or fully block the flow of oxygen-rich blood to the portion of heart muscle fed by the artery. This causes a heart attack.
During a heart attack, some heart muscle cells die and are replaced with scar tissue. The scar tissue damages the heart's electrical system. As a result, electrical signals may spread abnormally throughout the heart. These changes to the heart increase the risk of dangerous arrhythmias and SCA.
CHD seems to cause most cases of SCA in adults. Many of these adults, however, have no signs or symptoms of CHD before having SCA.
Certain types of physical stress can cause your heart's electrical system to fail. Examples include:
A tendency to have arrhythmias runs in some families. This tendency is inherited, which means it's passed from parents to children through the genes. Members of these families may be at higher risk for SCA.
An example of an inherited disorder that makes you more likely to have arrhythmias is long QT syndrome (LQTS). LQTS is a disorder of the heart's electrical activity. Problems with tiny pores on the surface of heart muscle cells cause the disorder. LQTS can cause sudden, uncontrollable, dangerous heart rhythms.
People who inherit structural heart problems also may be at higher risk for SCA. These types of problems often are the cause of SCA in children.
Changes in the heart's normal size or structure may affect its electrical system. Examples of such changes include an enlarged heart due to high blood pressure or advanced heart disease. Heart infections also may cause structural changes in the heart.
The risk of sudden cardiac arrest (SCA) increases:
The major risk factor for SCA is coronary heart disease. Most people who have SCA have some degree of coronary heart disease; however, many people may not know that they have coronary heart disease until SCA occurs. Usually their coronary heart disease is “silent”—that is, it has no signs or symptoms. Because of this, doctors and nurses have not detected it.
Many people who have SCA also have silent, or undiagnosed, heart attacks before sudden cardiac arrest happens. These people have no clear signs of heart attack, and they don’t even realize that they’ve had one. Read more about coronary heart disease risk factors.
Other risk factors for SCA include:
Usually, the first sign of sudden cardiac arrest (SCA) is loss of consciousness (fainting). At the same time, no heartbeat (or pulse) can be felt.
Some people may have a racing heartbeat or feel dizzy or light-headed just before they faint. Within an hour before SCA, some people have chest pain, shortness of breath, nausea (feeling sick to the stomach), or vomiting.
Sudden cardiac arrest (SCA) happens without warning and requires emergency treatment. Doctors rarely diagnose SCA with medical tests as it's happening. Instead, SCA often is diagnosed after it happens. Doctors do this by ruling out other causes of a person's sudden collapse.
If you're at high risk for SCA, your doctor may refer you to a cardiologist. This is a doctor who specializes in diagnosing and treating heart diseases and conditions. Your cardiologist will work with you to decide whether you need treatment to prevent SCA.
Some cardiologists specialize in problems with the heart's electrical system. These specialists are called cardiac electrophysiologists.
Doctors use several tests to help detect the factors that put people at risk for SCA.
An EKG is a simple, painless test that detects and records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through each part of the heart.
An EKG can show evidence of heart damage due to coronary heart disease (CHD). The test also can show signs of a previous or current heart attack.
Echocardiography, or echo, is a painless test that uses sound waves to create pictures of your heart. The test shows the size and shape of your heart and how well your heart chambers and valves are working.
Echo also can identify areas of poor blood flow to the heart, areas of heart muscle that aren't contracting normally, and previous injury to the heart muscle caused by poor blood flow.
There are several types of echo, including stress echo. This test is done both before and after a cardiac stress test. During this test, you exercise (or are given medicine if you're unable to exercise) to make your heart work hard and beat fast.
Stress echo shows whether you have decreased blood flow to your heart (a sign of CHD).
A MUGA (multiple gated acquisition) test shows how well your heart is pumping blood. For this test, a small amount of radioactive substance is injected into a vein and travels to your heart.
The substance releases energy, which special cameras outside of your body can detect. The cameras use the energy to create pictures of many parts of your heart.
Cardiac MRI (magnetic resonance imaging) is a safe procedure that uses radio waves and magnets to create detailed pictures of your heart. The test creates still and moving pictures of your heart and major blood vessels.
Doctors use cardiac MRI to get pictures of the beating heart and to look at the structure and function of the heart.
Cardiac catheterization is a procedure used to diagnose and treat certain heart conditions. A long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck and threaded to your heart. Through the catheter, your doctor can do diagnostic tests and treatments on your heart.
Sometimes dye is put into the catheter. The dye will flow through your bloodstream to your heart. The dye makes your coronary (heart) arteries visible on x-ray pictures. The dye can show whether plaque has narrowed or blocked any of your coronary arteries.
For an electrophysiology study, doctors use cardiac catheterization to record how your heart's electrical system responds to certain medicines and electrical stimulation. This helps your doctor find where the heart's electrical system is damaged.
Your doctor may recommend blood tests to check the levels of potassium, magnesium, and other chemicals in your blood. These chemicals play an important role in your heart's electrical signaling.
Sudden cardiac arrest (SCA) is an emergency. A person having SCA needs to be treated with a defibrillator right away. This device sends an electric shock to the heart. The electric shock can restore a normal rhythm to a heart that's stopped beating.
To work well, defibrillation must be done within minutes of SCA. With every minute that passes, the chances of surviving SCA drop rapidly.
Police, emergency medical technicians, and other first responders usually are trained and equipped to use a defibrillator. Call 9–1–1 right away if someone has signs or symptoms of SCA. The sooner you call for help, the sooner lifesaving treatment can begin.
Automated external defibrillators (AEDs) are special defibrillators that untrained bystanders can use. These portable devices often are found in public places, such as shopping malls, golf courses, businesses, airports, airplanes, casinos, convention centers, hotels, sports venues, and schools.
AEDs are programmed to give an electric shock if they detect a dangerous arrhythmia, such as ventricular fibrillation. This prevents giving a shock to someone who may have fainted but isn't having SCA.
You should give cardiopulmonary resuscitation (CPR) to a person having SCA until defibrillation can be done.
People who are at risk for SCA may want to consider having an AED at home. A 2008 study by the National Heart, Lung, and Blood Institute and the National Institutes of Health found that AEDs in the home are safe and effective.
Some people feel that placing these devices in homes will save many lives because many SCAs occur at home. Others note that no evidence supports the idea that home-use AEDs save more lives. These people fear that people who have AEDs in their homes will delay calling for help during an emergency. They're also concerned that people who have home-use AEDs will not properly maintain the devices or forget where they are.
When considering a home-use AED, talk with your doctor. He or she can help you decide whether having an AED in your home will benefit you.
If you survive SCA, you'll likely be admitted to a hospital for ongoing care and treatment. In the hospital, your medical team will closely watch your heart. They may give you medicines to try to reduce the risk of another SCA.
While in the hospital, your medical team will try to find out what caused your SCA. If you're diagnosed with coronary heart disease, you may have percutaneous coronary intervention, also known as coronary angioplasty, or coronary artery bypass grafting. These procedures help restore blood flow through narrowed or blocked coronary arteries.
Often, people who have SCA get a device called an implantable cardioverter defibrillator (ICD). This small device is surgically placed under the skin in your chest or abdomen. An ICD uses electric pulses or shocks to help control dangerous arrhythmias. (For more information, go to "How Can Death Due to Sudden Cardiac Arrest Be Prevented?")
Ways to prevent death due to sudden cardiac arrest (SCA) differ depending on whether:
If you've already had SCA, you're at high risk of having it again. Research shows that an implantable cardioverter defibrillator (ICD) reduces the chances of dying from a second SCA. An ICD is surgically placed under the skin in your chest or abdomen. The device has wires with electrodes on the ends that connect to your heart's chambers. The ICD monitors your heartbeat.
If the ICD detects a dangerous heart rhythm, it gives an electric shock to restore the heart's normal rhythm. Your doctor may give you medicine to limit irregular heartbeats that can trigger the ICD.
An ICD isn't the same as a pacemaker. The devices are similar, but they have some differences. Pacemakers give off low-energy electrical pulses. They're often used to treat less dangerous heart rhythms, such as those that occur in the upper chambers of the heart. Most new ICDs work as both pacemakers and ICDs.
If you have severe coronary heart disease (CHD), you're at increased risk for SCA. This is especially true if you've recently had a heart attack.
Your doctor may prescribe a type of medicine called a beta blocker to help lower your risk for SCA. Your doctor also may discuss beginning statin treatment if you have an elevated risk for developing heart disease or having a stroke. Doctors usually prescribe statins for people who have:
Your doctor also may prescribe other medications to:
Take all medicines regularly, as your doctor prescribes. Don’t change the amount of your medicine or skip a dose unless your doctor tells you to. You should still follow a heart-healthy lifestyle, even if you take medicines to treat your coronary heart disease.
Other treatments for coronary heart disease—such as percutaneous coronary intervention, also known as coronary angioplasty, or coronary artery bypass grafting—also may lower your risk for SCA. Your doctor also may recommend an ICD if you’re at high risk for SCA.
CHD seems to be the cause of most SCAs in adults. CHD also is a major risk factor for angina (chest pain or discomfort) and heart attack, and it contributes to other heart problems.
Following a healthy lifestyle can help you lower your risk for CHD, SCA, and other heart problems. A heart-healthy lifestyle includes:
Heart-healthy eating is an important part of a heart-healthy lifestyle. Your doctor may recommend heart-healthy eating, which should include:
When following a heart-healthy diet, you should avoid eating:
Two nutrients in your diet make blood cholesterol levels rise:
Saturated fat raises your blood cholesterol more than anything else in your diet. When you follow a heart-healthy eating plan, only 5 percent to 6 percent of your daily calories should come from saturated fat. Food labels list the amounts of saturated fat. To help you stay on track, here are some examples:
|
If you eat: |
Try to eat no more than: |
|
1,200 calories a day |
8 grams of saturated fat a day |
|
1,500 calories a day |
10 grams of saturated fat a day |
|
1,800 calories a day |
12 grams of saturated fat a day |
|
2,000 calories a day |
13 grams of saturated fat a day |
|
2,500 calories a day |
17 grams of saturated fat a day |
Not all fats are bad. Monounsaturated and polyunsaturated fats actually help lower blood cholesterol levels. Some sources of monounsaturated and polyunsaturated fats are:
You should try to limit the amount of sodium that you eat. This means choosing and preparing foods that are lower in salt and sodium. Try to use low-sodium and “no added salt” foods and seasonings at the table or while cooking. Food labels tell you what you need to know about choosing foods that are lower in sodium. Try to eat no more than 2,300 milligrams of sodium a day. If you have high blood pressure, you may need to restrict your sodium intake even more.
Your doctor may recommend the Dietary Approaches to Stop Hypertension (DASH) eating plan if you have high blood pressure. The DASH eating plan focuses on fruits, vegetables, whole grains, and other foods that are heart healthy and low in fat, cholesterol, and sodium and salt.
The DASH eating plan is a good heart-healthy eating plan, even for those who don’t have high blood pressure. Read more about DASH.
Try to limit alcohol intake. Too much alcohol can raise your blood pressure and triglyceride levels, a type of fat found in the blood. Alcohol also adds extra calories, which may cause weight gain.
Men should have no more than two drinks containing alcohol a day. Women should have no more than one drink containing alcohol a day. One drink is:
Maintaining a healthy weight is important for overall health and can lower your risk for sudden cardiac arrest. Aim for a Healthy Weight by following a heart-healthy eating plan and keeping physically active.
Knowing your body mass index (BMI) helps you find out if you’re a healthy weight in relation to your height and gives an estimate of your total body fat. To figure out your BMI, check out the National Heart, Lung, and Blood Institute’s online BMI calculator or talk to your doctor. A BMI:
A general goal to aim for is a BMI of less than 25. Your doctor or health care provider can help you set an appropriate BMI goal.
Measuring waist circumference helps screen for possible health risks. If most of your fat is around your waist rather than at your hips, you’re at a higher risk for heart disease and type 2 diabetes. This risk may be higher with a waist size that is greater than 35 inches for women or greater than 40 inches for men. To learn how to measure your waist, visit Assessing Your Weight and Health Risk.
If you’re overweight or obese, try to lose weight. A loss of just 3 percent to 5 percent of your current weight can lower your triglycerides, blood glucose, and the risk of developing type 2 diabetes. Greater amounts of weight loss can improve blood pressure readings, lower LDL cholesterol, and increase HDL cholesterol.
Managing and coping with stress. Learning how to manage stress, relax, and cope with problems can improve your emotional and physical health. Consider healthy stress-reducing activities, such as:
Regular physical activity can lower your risk for coronary heart disease, sudden cardiac arrest, and other health problems. Everyone should try to participate in moderate-intensity aerobic exercise at least 2 hours and 30 minutes per week or vigorous aerobic exercise for 1 hour and 15 minutes per week. Aerobic exercise, such as brisk walking, is any exercise in which your heart beats faster and you use more oxygen than usual. The more active you are, the more you will benefit. Participate in aerobic exercise for at least 10 minutes at a time spread throughout the week.
Talk with your doctor before you start a new exercise plan. Ask your doctor how much and what kinds of physical activity are safe for you.
Read more about physical activity at:
People who smoke are more likely to have a heart attack than are people who don’t smoke. The risk of having a heart attack increases with the number of cigarettes smoked each day. Smoking also raises your risk for stroke and lung diseases, such as chronic obstructive pulmonary disease (COPD) and lung cancer.
Quitting smoking can greatly reduce your risk for heart and lung diseases. Ask your doctor about programs and products that can help you quit. Also, try to avoid secondhand smoke. If you have trouble quitting smoking on your own, consider joining a support group. Many hospitals, workplaces, and community groups offer classes to help people quit smoking. Read more about how to quit smoking.
Click here for Difference between Heart Attack and Sudden Cardiac Arrest
The National Heart, Lung, and Blood Institute (NHLBI) is strongly committed to supporting research aimed at preventing and treating heart, lung, and blood diseases and conditions and sleep disorders.
NHLBI-supported research has led to many advances in medical knowledge and care. Often, these advances depend on the willingness of volunteers to take part in clinical trials.
Clinical trials test new ways to prevent, diagnose, or treat various diseases and conditions. For example, new treatments for a disease or condition (such as medicines, medical devices, surgeries, or procedures) are tested in volunteers who have the illness. Testing shows whether a treatment is safe and effective in humans before it is made available for widespread use.
By taking part in a clinical trial, you can gain access to new treatments before they're widely available. You also will have the support of a team of health care providers, who will likely monitor your health closely. Even if you don't directly benefit from the results of a clinical trial, the information gathered can help others and add to scientific knowledge.
If you volunteer for a clinical trial, the research will be explained to you in detail. You'll learn about treatments and tests you may receive, and the benefits and risks they may pose. You'll also be given a chance to ask questions about the research. This process is called informed consent.
If you agree to take part in the trial, you'll be asked to sign an informed consent form. This form is not a contract. You have the right to withdraw from a study at any time, for any reason. Also, you have the right to learn about new risks or findings that emerge during the trial.
For more information about clinical trials related to sudden cardiac arrest, talk with your doctor. You also can visit the following Web sites to learn more about clinical research and to search for clinical trials:
For more information about clinical trials for children, visit the NHLBI's Children and Clinical Studies Web page.
Sudden Cardiac Arrest Clinical Trials
Learn more about other sudden cardiac arrest trials and how to participate in a clinical trial.
Source: NHLBI, NIH
New treatments are available that greatly reduce the damage caused by a stroke. But you need to arrive at the hospital as soon as possible after symptoms start to prevent disability and to greatly improve your chances for recovery. Knowing stroke symptoms, calling 911 immediately, and getting to a hospital as quickly as possible are critical
About Stroke
Stroke -- A Serious Event
A stroke is serious, just like a heart attack. Each year in the United States, approximately 795,000 people have a stroke. About 610,000 of these are first or new strokes. On average, one American dies from stroke every four minutes. Stroke is the fourth leading cause of death in the United States, and causes more serious long-term disabilities than any other disease.
Nearly three-quarters of all strokes occur in people over the age of 65. And the risk of having a stroke more than doubles each decade between the ages of 55 and 85.
Stroke occurs in all age groups, in both sexes, and in all races in every country. It can even occur before birth, when the fetus is still in the womb.
Learning about stroke can help you act in time to save a relative, neighbor, or friend. And making changes in your lifestyle can help you prevent stroke.
What Is Stroke?
A stroke is sometimes called a "brain attack." Most often, stroke occurs when blood flow to the brain stops because it is blocked by a clot. When this happens, the brain cells in the immediate area begin to die.
Some brain cells die because they stop getting the oxygen and nutrients they need to function. Other brain cells die because they are damaged by sudden bleeding into or around the brain. The brain cells that don't die immediately remain at risk for death. These cells can linger in a compromised or weakened state for several hours. With timely treatment, these cells can be saved.
New treatments are available that greatly reduce the damage caused by a stroke. But you need to arrive at the hospital as soon as possible after symptoms start to prevent disability and to greatly improve your chances for recovery. Knowing stroke symptoms, calling 911 immediately, and getting to a hospital as quickly as possible are critical.
Ischemic Stroke
There are two kinds of stroke. The most common kind of stroke is called ischemic stroke. It accounts for approximately 80 percent of all strokes. An ischemic stroke is caused by a blood clot that blocks or plugs a blood vessel supplying blood to the brain. Blockages that cause ischemic strokes stem from three conditions:
the formation of a clot within a blood vessel of the brain or neck, called thrombosis
the movement of a clot from another part of the body, such as from the heart to the neck or brain, called an embolism
a severe narrowing of an artery (stenosis) in or leading to the brain, due to fatty deposits lining the blood vessel walls.
Hemorrhagic Stroke
The other kind of stroke is called hemorrhagic stroke. A hemorrhagic stroke is caused by a blood vessel that breaks and bleeds into the brain.
One common cause of a hemorrhagic stroke is a bleeding aneurysm. An aneurysm is a weak or thin spot on an artery wall. Over time, these weak spots stretch or balloon out due to high blood pressure. The thin walls of these ballooning aneurysms can rupture and spill blood into the space surrounding brain cells.
Artery walls can also break open because they become encrusted, or covered with fatty deposits called plaque, eventually lose their elasticity and become brittle, thin, and prone to cracking. Hypertension, or high blood pressure, increases the risk that a brittle artery wall will give way and release blood into the surrounding brain tissue.
Effects of a Stroke
The brain is the most complex organ in the human body. It is the seat of intelligence, interpreter of the senses, initiator of all movement, and the controller of behavior. How a stroke affects us depends on which part of the brain is damaged.
Stroke damage in the brain can affect the entire body -- resulting in mild to severe disabilities. These include paralysis, problems with thinking, trouble speaking, and emotional problems.
Movement Problems
A common disability that results from stroke is complete paralysis on one side of the body, called hemiplegia. A related disability that is not as debilitating as paralysis is one-sided weakness, or hemiparesis. The paralysis or weakness may affect only the face, an arm, or a leg, or it may affect one entire side of the body and face.
A stroke patient may have problems with the simplest of daily activities, such as walking, dressing, eating, and using the bathroom. Movement problems can result from damage to the part of the brain that controls balance and coordination. Some stroke patients also have trouble swallowing, called dysphagia.
Thinking Problems
Stroke may cause problems with thinking, awareness, attention, learning, judgment, and memory.
In some cases of stroke, the patient suffers a "neglect" syndrome. The neglect syndrome means that the stroke patient has no knowledge of one side of his or her body, or one side of the visual field, and is unaware of the problem. A stroke patient may be unaware of his or her surroundings, or may be unaware of the mental problems that resulted from the stroke.
Speech Problems
Stroke victims often have a problem forming or understanding speech. This problem is called aphasia. Aphasia usually occurs along with similar problems in reading and writing. In most people, language problems result from damage to the left hemisphere of the brain.
Slurred speech due to weakness or incoordination of the muscles involved in speaking is called dysarthria, and is not a problem with language. Because it can result from any weakness or incoordination of the speech muscles, dysarthria can arise from damage to either side of the brain.
Emotional Problems
A stroke can also lead to emotional problems. Stroke patients may have difficulty controlling their emotions or may express inappropriate emotions in certain situations. One common disability that occurs with many stroke patients is depression.
Post-stroke depression may be more than a general sadness resulting from the stroke incident. It is a serious behavioral problem that can hamper recovery and rehabilitation and may even lead to suicide. Post-stroke depression is treated as any depression is treated, with antidepressant medications and therapy.
Stroke patients may experience pain, uncomfortable numbness, or strange sensations after a stroke. These sensations may be due to many factors, including damage to the sensory regions of the brain, stiff joints, or a disabled limb.
Pain
An uncommon type of pain resulting from stroke is called central stroke pain or central pain syndrome or CPS. CPS results from damage to an area called the thalamus. The pain is a mixture of sensations, including heat and cold, burning, tingling, numbness, and sharp stabbing and underlying aching pain.
The pain is often worse in the hands and feet and is made worse by movement and temperature changes, especially cold temperatures. Unfortunately, since most pain medications provide little relief from these sensations, very few treatments or therapies exist to combat CPS.
Brain Stem Stroke
The brain stem controls vital bodily functions such as breathing, blood pressure and heartbeat. A stroke in the brain stem can be fatal or can leave someone in a “locked-in” state in which the person cannot control anything below the neck. As with other types of stroke, early treatment is crucial.
Warning Signs of Stroke
Know the Signs
Knowing the warning signs of stroke and controlling stroke's risk factors can lower your risk of death or disability. If you suffer a stroke, you may not realize it at first. The people around you might not know it, either. Your family, friends, or neighbors may think you are unaware or confused. You may not be able to call 911 on your own. That's why everyone should know the signs of stroke and know how to act fast.
Warning signs are clues your body sends to tell you that your brain is not receiving enough oxygen. If you observe one or more of the following signs of a stroke or "brain attack," don't wait. Call 911 right away!
Common Signs of Stroke
These are warning signs of a stroke:
sudden numbness or weakness of the face, arm, or leg, especially on one side of the body
sudden confusion, trouble speaking or understanding
sudden trouble seeing in one or both eyes
sudden trouble walking, dizziness, loss of balance or coordination
sudden severe headache with no known cause.
Other danger signs that may occur include double vision, drowsiness, and nausea or vomiting.
Don't Ignore "Mini-Strokes"
Sometimes the warning signs of stroke may last only a few moments and then disappear. These brief episodes, known as transient ischemic attacks or TIAs, are sometimes called "mini-strokes."
Although brief, TIAs identify an underlying serious condition that isn't going away without medical help. Unfortunately, since they clear up, many people ignore them. Don't ignore them. Heeding them can save your life.
Why It's Important To Act Fast
Stroke is a medical emergency. Every minute counts when someone is having a stroke. The longer blood flow is cut off to the brain, the greater the damage. Immediate treatment can save people’s lives and enhance their chances for successful recovery.
Ischemic strokes, the most common type of strokes, can be treated with a drug called t-PA that dissolves blood clots obstructing blood flow to the brain. The window of opportunity to start treating stroke patients is three hours, but to be evaluated and receive treatment, patients need to get to the hospital within 60 minutes.
What Should You Do?
Don't wait for the symptoms of stroke to improve or worsen. If you believe you are having a stroke, call 911 immediately. Making the decision to call for medical help can make the difference in avoiding a lifelong disability and in greatly improving your chances for recovery.
If you observe someone having a stroke – if he or she suddenly loses the ability to speak, or move an arm or leg on one side, or experiences facial paralysis on one side – call 911 immediately.
Risk Factors for Stroke
A risk factor is a condition or behavior that increases your chances of getting a disease. Having a risk factor for stroke doesn't mean you'll have a stroke. On the other hand, not having a risk factor doesn't mean you'll avoid a stroke. But your risk of stroke grows as the number and severity of risk factors increase.
These risk factors for stroke cannot be changed by medical treatment or lifestyle changes.
Age. Although stroke risk increases with age, stroke can occur at any age. Recent studies have found that stroke rates among people under 55 grew from 13 percent in 1993-1994, to 19 percent in 2005. Experts speculate the increase may be due to a rise in risk factors such as diabetes, obesity, and high cholesterol.
Gender. Men have a higher risk for stroke, but more women die from stroke.
Race. People from certain ethnic groups have a higher risk of stroke. For African Americans, stroke is more common and more deadly – even in young and middle-aged adults – than for any ethnic or other racial group in the U.S. Studies show that the age-adjusted incidence of stroke is about twice as high in African Americans and Hispanic Americans as in Caucasians. An important risk factor for African Americans is sickle cell disease, which can cause a narrowing of arteries and disrupt blood flow.
Family history of stroke. Stroke seems to run in some families. Several factors may contribute to familial stroke. Members of a family might have a genetic tendency for stroke risk factors, such as an inherited predisposition for high blood pressure (hypertension) or diabetes. The influence of a common lifestyle among family members could also contribute to familial stroke.
Some of the most important risk factors for stroke that CAN be treated are
high blood pressure
smoking
heart disease
high blood cholesterol
warning signs or history of a stroke
diabetes.
High Blood Pressure
High blood pressure, also called hypertension, is by far the most potent risk factor for stroke. If your blood pressure is high, you and your doctor need to work out an individual strategy to bring it down to the normal range. Here are some ways to reduce blood pressure:
Maintain proper weight.
Avoid drugs known to raise blood pressure.
Cut down on salt.
Eat fruits and vegetables to increase potassium in your diet.
Exercise more.
Your doctor may prescribe medicines that help lower blood pressure. Controlling blood pressure will also help you avoid heart disease, diabetes, and kidney failure.
Smoking
Cigarette smoking has been linked to the buildup of fatty substances in the carotid artery, the main neck artery supplying blood to the brain. Blockage of this artery is the leading cause of stroke in Americans. Also, nicotine raises blood pressure, carbon monoxide reduces the amount of oxygen your blood can carry to the brain, and cigarette smoke makes your blood thicker and more likely to clot.
Your doctor can recommend programs and medications that may help you quit smoking. By quitting -- at any age -- you also reduce your risk of lung disease, heart disease, and a number of cancers including lung cancer.
Heart Disease
Heart disease, including common heart disorders such as coronary artery disease, valve defects, irregular heart beat, and enlargement of one of the heart's chambers, can result in blood clots that may break loose and block vessels in or leading to the brain. The most common blood vessel disease, caused by the buildup of fatty deposits in the arteries, is called atherosclerosis, also known as hardening of the arteries.
Your doctor will treat your heart disease and may also prescribe medication, such as aspirin, to help prevent the formation of clots. Your doctor may recommend surgery to clean out a clogged neck artery if you match a particular risk profile.
High Blood Cholesterol
A high level of total cholesterol in the blood is a major risk factor for heart disease, which raises your risk of stroke. Your doctor may recommend changes in your diet or medicines to lower your cholesterol.
Warning Signs or History of Stroke
Experiencing warning signs and having a history of stroke are also risk factors for stroke. Transient ischemic attacks, or TIAs, are brief episodes of stroke warning signs that may last only a few moments and then go away. If you experience a TIA, get help at once. Call 911.
If you have had a stroke in the past, it's important to reduce your risk of a second stroke. Your brain helps you recover from a stroke by drawing on body systems that now do double duty. That means a second stroke can be twice as bad.
Diabetes
Having diabetes is another risk factor for stroke. You may think this disorder affects only the body's ability to use sugar, or glucose. But it also causes destructive changes in the blood vessels throughout the body, including the brain.
Also, if blood glucose levels are high at the time of a stroke, then brain damage is usually more severe and extensive than when blood glucose is well-controlled. Treating diabetes can delay the onset of complications that increase the risk of stroke.
Prevention and Diagnosis
Stroke is preventable and treatable. A better understanding of the causes of stroke has helped people make lifestyle changes that have cut the stroke death rate nearly in half in the last two decades.
Preventing Stroke
While family history of stroke plays a role in your risk, there are many risk factors you can control:
If you have high blood pressure, work with your doctor to get it under control.
If you smoke, quit.
If you have diabetes, learn how to manage it. Many people do not realize they have diabetes, which is a major risk factor for heart disease and stroke.
If you are overweight, start maintaining a healthy diet and exercising regularly.
If you have high cholesterol, work with your doctor to lower it. A high level of total cholesterol in the blood is a major risk factor for heart disease, which raises your risk of stroke.
Diagnosing Stroke
Physicians have several diagnostic techniques and imaging tools to help diagnose stroke quickly and accurately. The first step in diagnosis is a short neurological examination, or an evaluation of the nervous system.
When a possible stroke patient arrives at a hospital, a health care professional, usually a doctor or nurse, will ask the patient or a companion what happened and when the symptoms began. Blood tests, an electrocardiogram, and a brain scan such as computed tomography or CT, or magnetic resonance imaging or MRI, will often be done.
Measuring Stroke Severity
One test that helps doctors judge the severity of a stroke is the standardized NIH Stroke Scale, developed by the National Institute of Neurological Disorders and Stroke at the National Institutes of Health, or NIH. Health care professionals use the NIH Stroke Scale to measure a patient's neurological deficits by asking the patient to answer questions and to perform several physical and mental tests.
Other scales include the Glasgow Coma Scale, the Hunt and Hess Scale, the Modified Rankin Scale, and the Barthel Index.
Diagnostic Imaging: CT Scan
Health care professionals also use a variety of imaging techniques to evaluate acute stroke patients. The most widely used is computed tomography or CT scan, sometimes pronounced “CAT” scan, which is comprised of a series of cross-sectional images of the head and brain.
CT scans are sensitive for detecting hemorrhage and are therefore useful for differentiating hemorrhagic stroke, caused by bleeding in the brain, from ischemic stroke, caused by a blockage of blood flow to the brain.
Hemorrhage is the primary reason for avoiding thrombolytic therapy (drugs that break up or dissolve blood clots), the only proven therapy for acute ischemic stroke.
Because thrombolytic therapy might make a hemorrhagic stroke worse, doctors must confirm that the acute symptoms are not due to hemorrhage prior to giving the drug.
A CT scan may show evidence of early ischemia – an area of tissue that is dead or dying due to a loss of blood supply. Ischemic strokes generally show up on a CT scan about six to eight hours after the start of stroke symptoms. Though not as common in practice, CT scans also can be performed with a contrast agent to help visualize a blockage in the large arteries supplying the brain, or detect areas of decreased blood flow to the brain.
Because CT is readily available at all hours at most major hospitals, produces images quickly, and is good for ruling out hemorrhage prior to starting thrombolytic therapy, CT is the most widely used diagnostic imaging technique for acute stroke.
Diagnostic Imaging: MRI Scan
Another imaging technique used in acute stroke patients is the magnetic resonance imaging or MRI scan. MRI uses magnetic fields to detect a variety of changes in the brain and blood vessels caused by a stroke. One effect of ischemic stroke is the slowing of water movement through the injured brain tissue. Because MRI can show this type of injury very soon after stroke symptoms start, MRI has proven useful for diagnosing acute ischemic stroke before it is visible on CT. MRI also allows doctors to visualize blockages in the arteries, identify sites of prior stroke, and create a stroke treatment and prevention plan.
Differences Between CT and MRI Scans
MRI and CT are equally accurate for determining when hemorrhage is present. The benefit of MRI over a CT scan is more accurate and earlier diagnosis of ischemic stroke, especially for smaller strokes and transient ischemic attacks (TIAs). MRI can be more sensitive than CT for detecting other types of neurological disorders that mimic the symptoms of stroke. However, MRI cannot be performed in patients with certain types of metallic or electronic implants, such as pacemakers for the heart.
Although increasingly used in the emergency diagnosis of stroke, MRI is not immediately available at all hours in most hospitals, where CT is used for acute stroke diagnosis. MRI typically takes longer to perform than CT, and therefore may not be the first choice when minutes count.
Medications
With stroke, treatment depends on the stage of the disease. There are three treatment stages for stroke: prevention, therapy immediately after stroke, and rehabilitation after stroke. Stroke therapies include medications, surgery, and rehabilitation.
Medication or drug therapy is the most common treatment for stroke. The most popular kinds of drugs to prevent or treat stroke are antithrombotics -- which include antiplatelet agents and anticoagulants -- and thrombolytics.
Thrombolytics
In treating a stroke that has just occurred, every minute counts. Ischemic strokes -- the most common kind -- can be treated with thrombolytic drugs. These drugs halt the stroke by dissolving the blood clot that is blocking blood flow to the brain. But a person needs to be at the hospital as soon as possible after stroke symptoms start to be evaluated and receive treatment.
A thrombolytic drug known as t-PA can be effective if a person receives it intravenously (in a vein) within 3 hours after his or her stroke symptoms have started. Because there is such a narrow time window for giving t-PA, it is important to note the time any stroke symptoms appear. Since thrombolytic drugs can increase bleeding, t-PA should be used only after the doctor is certain that the patient has suffered an ischemic and not a hemorrhagic stroke.
Antithrombotics
Antithrombotics prevent the formation of blood clots that can become stuck in an artery of the brain and cause strokes. Antiplatelet drugs prevent clotting by decreasing the activity of platelets, which are blood cells that help blood clot. By reducing the risk of blood clots, these drugs lower the risk of ischemic stroke.
In the case of stroke, doctors prescribe antiplatelet drugs mainly for prevention. The most widely known and used antiplatelet drug is aspirin. Other antiplatelet drugs include clopidogrel, ticlopidine, and dipyridamole.
Other Drugs
Anticoagulants reduce the risk of stroke by reducing the clotting property of the blood. The most commonly used oral anticoagulants include warfarin, also known as Coumadin®, dabigatran (Pradaxa) and rivaroxaban (Xarelto). Injectable anticoagulants include heparin, enoxaparin (Lovenox), and dalteparin (Fragmin).
Neuroprotectants are medications or other treatments that protect the brain from secondary injury caused by stroke. Although the FDA (Food and Drug Administration) has not approved any neuroprotectants for use in stroke at this time, many have been tested or are being tested in clinical trials. Cooling of the brain (hypothermia) is beneficial for improving neurological function after a cardiac arrest.
Surgery and Vascular Procedures
Surgery and vascular procedures can be used to prevent stroke, to treat stroke, or to repair damage to the blood vessels or malformations in and around the brain.
Surgery
Carotid endarterectomy is a surgical procedure in which a surgeon removes fatty deposits, or plaque, from the inside of one of the carotid arteries. The procedure is performed to prevent stroke. The carotid arteries are located in the neck and are the main suppliers of blood to the brain.
Specialized Catheters Aid Vascular Procedures
In addition to surgery, a variety of techniques have been developed to allow certain vascular problems to be treated from inside the artery using specialized catheters with the goal of improving blood flow. Vascular is a word that refers to blood vessels, arteries, and veins that carry blood throughout the body.
A catheter is a very thin, flexible tube that can be inserted into one of the major arteries of the leg or arm and then directed through the blood vessels to the diseased artery. Physicians trained in this technique called angiography undergo additional training to treat problems in the arteries of the brain or spinal cord. These physicians are called neurointerventionalists.
The NINDS study, Carotid Revascularization Endarterectomy vs. Stenting Trial, (CREST), compared carotid artery stenting with endarterectomy and found that these two surgical procedures are equally effective in preventing future strokes. Your physician can talk to you about the best option for you. For more information about treating arterial stenosis and preventing stroke, visit http://www.ninds.nih.gov/disorders/stroke/arterial_stenosis_backgrounder.htm.
Clipping
One useful surgical procedure for treatment of brain aneurysms to prevent hemorrhage, or bleeding around the brain, is a technique called "clipping." An aneurysm is a weak or thin spot that develops on the wall of an artery or vein. Clipping involves an operation to apply a metal clip that closes off the aneurysm from the blood vessel, which greatly reduces the chance that it will bleed.
Detachable Coil Technique
The detachable coil technique is used by angiographers to treat intracranial aneurysms, or aneurysms that occur inside the skull. Angiographers use a catheter to insert a small platinum coil into the aneurysm, where it triggers clotting of the aneurysm. Stents are sometimes used to keep the normal artery open while the aneurysm clots off.
Arteriovenous Malformation
Arteriovenous malformations are a tangle of blood vessels inside the brain which may carry risk of bleeding. Surgery to remove the blood vessels may be possible in some patients. Angiographers can also sometimes insert a glue-like material to close off the feeding arteries to the tangled vessels. Radiation therapy can be used in small arteriovenous malformations to cause scarring and closing of the malformation over time.
Rehabilitation After Stroke
Stroke is the number one cause of serious adult disability in the United States. Stroke disability is devastating to the stroke patient and family, but therapies are available to help rehabilitate patients after stroke.
Physical Therapy
For most stroke patients, rehabilitation mainly involves physical therapy. The aim of physical therapy is to have the stroke patient relearn simple motor activities such as walking, sitting, standing, lying down, and the process of switching from one type of movement to another.
To achieve this, stroke patients work with physical therapists who use training, exercises, and physical manipulation of the stroke patient's body to restore movement, balance, and coordination.
Occupational Therapy
Another type of therapy to help patients relearn daily activities is occupational therapy. This type of therapy also involves exercise and training. Its goal is to help the stroke patient relearn everyday activities such as eating, drinking and swallowing, dressing, bathing, cooking, reading and writing, and toileting. Occupational therapists seek to help the patient become independent or semi-independent.
Speech Therapy
Speech and language problems arise when brain damage occurs in the language centers of the brain. Due to the brain's great ability to learn and change, which is called brain plasticity, other areas can adapt to take over some of the lost functions.
Speech therapy helps stroke patients relearn language and speaking skills, or learn other forms of communication. Speech therapy is appropriate for patients who have no problems with cognition or thinking, but have problems understanding speech or written words, or problems forming speech.
Besides helping with language skills, speech therapy also helps stroke patients develop coping skills to deal with the frustration of not being able to communicate fully. With time and patience, a stroke survivor should be able to regain some, and sometimes all, language and speaking abilities.
Therapy for Mental Health
Many stroke patients require psychological or psychiatric help after a stroke. Psychological problems such as depression, anxiety, frustration, and anger are common disabilities in people who have suffered a stroke.
Talk therapy, along with the right medication, can help ease some of the mental and emotional problems that result from stroke. Sometimes it is helpful for family members of the stroke patient to seek psychological help for themselves as well.
Stroke Research
The National Institute of Neurological Disorders and Stroke sponsors a wide range of basic and clinical research aimed at finding better ways to prevent, diagnose, and treat stroke, and to restore functions lost as a result of stroke.
Preventing Secondary Brain Damage
Currently, scientists are studying the risk factors for stroke and the process of brain damage that results from stroke. Some brain damage may be secondary, occurring after the initial death of brain cells caused by the lack of blood flow to the brain tissue.
This secondary brain damage results from a toxic reaction to the primary damage. Researchers are studying this toxic reaction and ways to prevent secondary injury to the brain. Scientists hope to develop neuroprotective agents, or drugs that protect the brain, to prevent this damage.
Animal Studies
Scientists are also conducting stroke studies in animals. By studying stroke in animals, researchers hope to get a better picture of what might be happening in human stroke patients. Scientists can also use animal models to test promising therapies for stroke. If a therapy proves helpful for animals, scientists can consider testing the therapy in humans.
One promising area of animal research involves hibernation. The dramatic decrease of blood flow to the brain in hibernating animals is so extensive that it would kill a non-hibernating animal. If scientists can discover how animals hibernate without experiencing brain damage, they may discover ways to stop the brain damage associated with decreased blood flow in stroke patients.
Another study used a vaccine that interferes with inflammation inside blood vessels to reduce the frequency and severity of strokes in animals with high blood pressure and a genetic predisposition to stroke. Researchers hope that the vaccine will work in humans and could be used to prevent many of the strokes that occur each year in people with high risk factors.
Can the Brain Repair Itself?
Scientists also are working to develop new and better ways to help the brain repair itself to restore important functions to stroke patients. New advances in imaging and rehabilitation have shown that the brain can compensate for functions lost as a result of stroke.
When cells in an area of the brain responsible for a particular function die after a stroke, the patient becomes unable to perform that function. However, the brain's ability to learn and change, called plasticity, and its ability to rewire the connections between its nerve cells means that it can compensate for lost functions. One part of the brain can actually change functions and take up the more important functions of a disabled part.
Clinical Trials
Clinical trials are scientific studies using volunteers that give researchers a way to test medical advances in humans. Clinical trials test surgical devices and procedures, medications, and rehabilitation therapies. They also test methods to improve lifestyles and mental and social skills.
Clinical trials may compare a new medical approach to a standard one that is already available or to a placebo that contains no active ingredients or to no intervention. Some clinical trials compare interventions that are already available to each other. When a new product or approach is being studied, it is not usually known whether it will be helpful, harmful, or no different than available alternatives (including no intervention). The investigators try to determine the safety and usefulness of the intervention by measuring certain outcomes in the participants.
Scientists are using clinical trials to
Participating in a clinical study contributes to medical knowledge. The results of these studies can make a difference in the care of future patients by providing information about the benefits and risks of therapeutic, preventative, or diagnostic products or interventions.
You can find more information about current stroke clinical trials at the NIH Clinical Trials Registry at www.clinicaltrials.gov. You can search for a trial using criteria such as condition or disease, medication or therapy. Each entry includes a trial description, sponsors, purpose, estimated completion date, eligibility criteria, and contact information.
You can also call the NIH research study information line at 1-800-411-1222, TTY-1-866-411-1010, or e-mail prpl@mail.cc.nih.gov
For more information on stroke, including research sponsored by the National Institute of Neurological Disorders and Stroke, call 1-800-352-9424 or visit the Web site at www.ninds.nih.gov.
Source: NIHSenior, NIH