What Is a Heart Attack?
A heart attack occurs if the flow of oxygen-rich blood to a section
of heart muscle suddenly becomes blocked. 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, call 9–1–1 right away.
Overview
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.
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.
Get Help Quickly
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. Heart attack symptoms include:
- Chest
pain or discomfort. This involves uncomfortable pressure, squeezing,
fullness, or pain in the center or left side of the chest that can be
mild or strong. This discomfort or pain often 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 upper part of the stomach.
- Shortness of breath, which may occur with or before chest discomfort.
- Nausea (feeling sick to your stomach), vomiting, light-headedness or sudden dizziness, or breaking out in a cold sweat.
Symptoms also may include sleep problems, fatigue (tiredness), and lack of energy. If you think you or someone else may be having a heart attack, call 9–1–1 right away. Quick treatment 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.
Outlook
Each year,
about 1.2 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.
Other Names for a Heart Attack:
- Myocardial infarction (MI)
- Acute myocardial infarction (AMI)
- Acute coronary syndrome
- Coronary thrombosis
- Coronary occlusion
What Causes a Heart Attack?
Coronary Heart Disease
A heart attack happens if the flow
of oxygen-rich blood to a section of heart muscle suddenly becomes
blocked. 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.
Coronary Artery Spasm
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:
- Taking certain drugs, such as cocaine
- Emotional stress or pain
- Exposure to extreme cold
- Cigarette smoking
Who Is at Risk for a Heart Attack?
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.
Risk Factors You Can Control
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 You Can't Control
Risk factors that you can't control include:
- Age. The risk of heart disease increases for men after age 45 and for women after age 55 (or after menopause).
- Family
history of early heart disease. Your risk increases if your father or a
brother was diagnosed with heart disease before 55 years of age, or if
your mother or a sister was diagnosed with heart disease before 65 years
of age.
- Preeclampsia
(pre-e-KLAMP-se-ah). This condition can develop during pregnancy. The
two main signs of preeclampsia are a rise in blood pressure and excess
protein in the urine. Preeclampsia is linked to an increased lifetime
risk of heart disease, including CHD, heart attack, heart failure, and high blood pressure.
What Are the Signs and Symptoms of a Heart Attack?
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
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. Heart attacks that occur without
any symptoms or very mild symptoms are called silent heart attacks.
Chest Pain or Discomfort
The
most common heart attack symptom is chest pain or discomfort. This
includes new chest pain or discomfort or a change in the pattern of
existing chest pain or discomfort.
Most heart attacks involve
discomfort in the center or left side of the chest that often lasts for
more than a few minutes or goes away and comes back. The discomfort can
feel like uncomfortable pressure, squeezing, fullness, or pain. The
feeling can be mild or severe.
Heart attack pain sometimes feels like indigestion or heartburn.
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.
Other Common Signs and Symptoms
Other common signs and symptoms of a heart attack include new onset of:
- Upper body discomfort in one or both arms, the back, neck, jaw, or upper part of the stomach
- Shortness of breath, which may occur with or before chest discomfort
- Nausea (feeling sick to your stomach), vomiting, light-headedness or sudden dizziness, or breaking out in a cold sweat
- Sleep problems, fatigue (tiredness), or lack of energy
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.
Act Fast!
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.
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 your heart will sustain.
Call
9–1–1 for help right away if you think you or someone else may be having
a heart attack. You also should call for help if your chest pain
doesn't go away as it usually does when you take medicine prescribed for
angina.
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.
For references, visit
Free E-Books on Heart Disease.
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