A heart attack occurs when blood flow to a section of heart muscle becomes blocked. If the flow of blood isn’t restored quickly, the section of heart muscle becomes damaged from lack of oxygen and begins to die.
Heart attack is a leading killer of both men and women in the United States. But fortunately, today there are excellent treatments for heart attack that can save lives and prevent disabilities. Treatment is most effective when started within 1 hour of the beginning of symptoms. If you think you or someone you’re with is having a heart attack, call 9–1–1 right away.
Heart attacks occur most often as a result of a condition called coronary artery disease (CAD). In CAD, a fatty material called plaque (plak) builds up over many years on the inside walls of the coronary arteries (the arteries that supply blood and oxygen to your heart). Eventually, an area of plaque can rupture, causing a blood clot to form on the surface of the plaque. If the clot becomes large enough, it can mostly or completely block the flow of oxygen-rich blood to the part of the heart muscle fed by the artery.
Figure A is an overview of a heart and coronary artery showing damage (dead heart muscle) caused by a heart attack. Figure B is a cross-section of the coronary artery with plaque buildup and a blood clot.
During a heart attack, if the blockage in the coronary artery isn’t treated quickly, the heart muscle will begin to die and be replaced by scar tissue. This heart damage may not be obvious, or it may cause severe or long-lasting problems.
Severe problems linked to heart attack can include heart failure and life-threatening arrhythmias (irregular heartbeats). Heart failure is a condition in which the heart can’t pump enough blood throughout the body. Ventricular fibrillation is a serious arrhythmia that can cause death if not treated quickly.
Get Help Quickly
Acting fast at the first sign of heart attack symptoms can save your life and limit damage to your heart. Treatment is most effective when started within 1 hour of the beginning of symptoms.
The most common heart attack signs and symptoms are:
- Chest discomfort or pain—uncomfortable pressure, squeezing, fullness, or pain in the center of the chest that can be mild or strong. This discomfort or pain lasts more than a few minutes or goes away and comes back.
- Upper body discomfort in one or both arms, the back, neck, jaw, or stomach.
- Shortness of breath may occur with or before chest discomfort.
- Other signs include nausea (feeling sick to your stomach), vomiting, lightheadedness or fainting, or breaking out in a cold sweat.
If you think you or someone you know may be having a heart attack:
- Call 9–1–1 within a few minutes—5 at the most—of the start of symptoms.
- If your symptoms stop completely in less than 5 minutes, still call your doctor.
- Only take an ambulance to the hospital. Going in a private car can delay treatment.
- Take a nitroglycerin pill if your doctor has prescribed this type of medicine.
Each year, about 1.1 million people in the United States have heart attacks, and almost half of them die. CAD, which often results in a heart attack, is the leading killer of both men and women in the United States.
Many more people could recover 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.
Signs and Symptoms
Not all heart attacks begin with a sudden, crushing pain that is often shown on TV or in the movies. The warning signs and symptoms of a heart attack aren’t the same for everyone. Many heart attacks start slowly as mild pain or discomfort. Some people don’t have symptoms at all (this is called a silent heart attack).
Chest Pain or Discomfort
The most common symptom of heart attack is chest pain or discomfort. Most heart attacks involve discomfort in the center of the chest that lasts for more than a few minutes or goes away and comes back. The discomfort can feel like uncomfortable pressure, squeezing, fullness, or pain. It can be mild or severe. Heart attack pain can sometimes feel like indigestion or heartburn.
The symptoms of angina can be similar to the symptoms of a heart attack. Angina is pain in the chest that occurs in people with coronary artery disease, usually when they’re active. Angina pain usually lasts for only a few minutes and goes away with rest. Angina that doesn’t go away or that changes from its usual pattern (occurs more frequently or occurs at rest) can be a sign of the beginning of a heart attack and should be checked by a doctor right away.
Other Common Signs and Symptoms
Other common signs and symptoms that a person can have during a heart attack include:
- Upper body discomfort in one or both arms, the back, neck, jaw, or stomach
- Shortness of breath may often occur with or before chest discomfort
- Nausea (feeling sick to your stomach), vomiting, lightheadedness or fainting, or breaking out in a cold sweat
Not everyone having a heart attack experiences the typical symptoms. If you’ve already had a heart attack, your symptoms may not be the same for another one. The more signs and symptoms you have, the more likely it is that you’re having a heart attack.
Sometimes the signs and symptoms of a heart attack happen suddenly, but they can also develop slowly, over hours, days, and even weeks before a heart attack occurs.
Know the warning signs of a heart attack so you can act fast to get treatment for yourself or someone else. The sooner you get emergency help, the less damage there will be to your heart.
Call 9–1–1 for help within 5 minutes if you think you may be having a heart attack or if your chest pain doesn’t go away as it usually does when you take prescribed medicine.
Don’t drive yourself or anyone else to the hospital. Call an ambulance so that medical personnel can begin life-saving treatment on the way to the emergency room.
The diagnosis of heart attack is based on your symptoms, your personal and family medical history, and the results of diagnostic tests.
This test detects and records the electrical activity of the heart. Certain changes in the appearance of the electrical waves on an EKG are strong evidence of a heart attack. An EKG also can show if you’re having arrhythmias (abnormal heartbeats), which a heart attack (and other conditions) can cause.
During a heart attack, heart muscle cells die and burst open, letting certain proteins out in the bloodstream. Blood tests can measure the amount of these proteins in the bloodstream. Higher than normal levels of these proteins in the bloodstream is evidence of a heart attack.
Commonly used blood tests include troponin tests, CK or CK–MB tests, and serum myoglobin tests. Blood tests are often repeated to check for changes over time.
Coronary angiography is a special x-ray exam of the heart and blood vessels. It's often done during a heart attack to help pinpoint blockages in the coronary arteries.
The doctor passes a catheter (a thin, flexible tube) through an artery in your arm or groin (upper thigh) and threads it to your heart. This procedure—called cardiac catheterization—is part of coronary angiography.
A dye that can be seen on x ray is injected into the bloodstream through the tip of the catheter. The dye lets the doctor study the flow of blood through the heart and blood vessels.
If a blockage is found, another procedure, called angioplasty, may be used to restore blood flow through the artery. Sometimes during angioplasty, the doctor will place a stent (a small mesh tube) in the artery to help keep the artery open.
Early treatment can prevent or limit damage to the heart muscle. Acting fast, at the first symptoms of heart attack, can save your life. Medical personnel can begin diagnosis and treatment even before you get to the hospital.
Certain treatments are usually started right away if a heart attack is suspected, even before the diagnosis is confirmed. These include:
- Aspirin to prevent further blood clotting
- Nitroglycerin, to reduce the workload on the heart and improve blood flow through the coronary arteries
- Treatment for chest pain
Once the diagnosis of heart attack is confirmed or strongly suspected, treatments to try to restore blood flow to the heart are started as soon as possible. Treatments include medicines and medical procedures.
A number of different kinds of medicines may be used to treat heart attack. They include the following.
These medicines (also called clot busters) are used to dissolve blood clots that are blocking the coronary arteries. To be most effective, these medicines must be given within 1 hour after the start of heart attack symptoms.
These medicines decrease the workload on your heart. Beta blockers also are used to relieve chest pain or discomfort and to help prevent additional heart attacks. Beta blockers also are used to correct arrhythmias (irregular heartbeats).
Angiotensin-Converting Enzyme (ACE) Inhibitors
These medicines lower blood pressure and reduce the strain on your heart. They also help slow down further weakening of the heart muscle.
These medicines thin the blood and prevent clots from forming in your arteries.
These medicines (such as aspirin and clopidogrel) stop platelets (a type of blood cell) from clumping together and forming unwanted clots.
Medicines may also be given to relieve pain and anxiety, and to treat arrhythmias, which often occur during a heart attack.
If medicines can’t stop a heart attack, medical procedures—surgical or nonsurgical—may be used. These procedures include the following.
This nonsurgical procedure can be used to open coronary arteries that are blocked by a blood clot. During angioplasty, a catheter (a thin, flexible tube) with a balloon on the end is threaded through a blood vessel to the blocked coronary artery. Then, the balloon is inflated to push the plaque against the wall of the artery. This widens the inside of the artery, restoring blood flow.
During angioplasty, a small mesh tube called a stent may be put in the artery to help keep it open. Some stents are coated with medicines that help prevent the artery from becoming blocked again.
Coronary Artery Bypass Grafting
Coronary artery bypass grafting is a surgery in which arteries or veins are taken from other areas of your body and sewn in place to bypass (that is, go around) blocked coronary arteries. This provides a new route for blood flow to the heart muscle.
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 recommend lifestyle changes, including quitting smoking, losing weight, changing your diet, and increasing your physical activity, to lower your chances of having another heart attack.
Your doctor may prescribe 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. The heart is a muscle, and the right exercise will strengthen it.
But cardiac rehab isn’t only about exercise. It also includes education, counseling, and learning about reducing your risk factors. Rehab will help you learn the best way to take care of yourself after having a heart attack and how to prevent having another one.
The cardiac rehab team may include doctors (your family doctor, a cardiologist, and/or a surgeon), nurses, exercise specialists, physical and occupational therapists, dietitians, and psychologists or other behavioral therapists.