What Is a Heart Attack?
A heart attack occurs when blood flow to a section
of heart muscle becomes blocked. If the flow of blood isnt 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 youre with is having a heart
attack, call 911 right away.
Overview
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.
Heart With Muscle Damage and a
Blocked Artery
![Figure A shows an overview of the heart and coronary artery. Figure B shows a cross-section of the coronary artery with plaque buildup and a blood clot.](https://webarchive.library.unt.edu/web/20090113201232im_/http://www.nhlbi.nih.gov/health/dci/images/heart_coronary_artery.gif)
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 isnt 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 cant 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 painuncomfortable
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 911 within a few minutes5
at the mostof 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.
Outlook
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.
March 2008
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