Heart Attack
(Myocardial Infarction)
Definition |
Causes |
Risk Factors |
Symptoms |
Diagnosis |
Treatment |
Prevention |
Organizations
Definition
A heart attack occurs when blood flow to the heart muscle is interrupted. This deprives the heart muscle of oxygen, causing tissue damage or tissue death.
Causes
A heart attack may be caused by:
- Thickening of the walls of the arteries feeding the heart muscle (coronary arteries)
- Accumulation of fatty plaques in the coronary arteries
- Narrowing of the coronary arteries
- Development of a blood clot in the coronary arteries
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition.
- Sex: Male
- Increased age
- Obesity
- Smoking
- High blood pressure
- Sedentary lifestyle
- High blood cholesterol (specifically, high LDL cholesterol, and low HDL cholesterol)
- High blood triglycerides
- Diabetes
- Stress
- Family members with heart disease
Symptoms
Symptoms include:
- Squeezing, heavy chest pain, especially with:
- Exercise or exertion
- Emotional stress
- Cold weather
- A large meal
- Pain in the left shoulder, left arm, or jaw
- Shortness of breath
- Sweating, clammy skin
- Nausea
- Weakness
- Loss of consciousness
Unusual symptoms of heart attack (may occur more frequently in women):
- Stomach pain
- Back pain
- Confusion
- Fainting
Diagnosis
If you think you are having a heart attack, call 911 immediately. You need emergency medical care.
Tests may include:
Blood Tests to look for certain substances found in the blood within hours or days after a heart attack. Blood tests will be repeated every 6-8 hours to track the progressive elevation of certain enzymes that indicate heart muscle damage.
Urine Tests to look for certain substances found in the urine within hours or days after a heart attack
Electrocardiogram (EKG) records the heart's activity by measuring electrical currents through the heart muscle. Certain abnormalities in the EKG occur when there is significant blockage of the coronary arteries and/or damage to the heart muscle. The EKG will be repeated to track the progression of these changes.
Echocardiogram uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart
Stress Test records the heart's electrical activity under increased physical demand
Thallium Stress Test thallium is used to scan the myocardium, the middle layer of the heart
Nuclear Scanning radioactive material is injected into a vein and observed as it is absorbed by the heart muscle
Electron-beam CT scan a type of x-ray that uses a computer to make pictures of the heart and surrounding structures
Coronary Angiography x-rays taken after a dye is injected into the arteries; to look for abnormalities in the arteries
Treatment
Treatment may include:
- Oxygen
- Pain-killing medications (such as morphine)
- Nitrate medications
- Atropine
- Beta-blocking and/or ACE inhibitor medications
- Anti-anxiety medications
- Clot-busting agents: within the first six hours after a heart attack, you may be given medications to break up blood clots in the coronary arteries. These include:
- Tissue plasminogen activator (tPA)
- Streptokinase
- APSAC
Surgery
Surgeries for people with severe blockages in their coronary arteries may include:
- Coronary bypass graft
- Atherectomy
- Balloon angioplasty with or without stenting
Physical or Rehabilitative Therapy
During recovery from a heart attack, you may need physical or rehabilitative therapy to help you regain your strength.
Psychotherapy or Antidepressant Medication
Some people have depression after suffering a heart attack. If you do, psychotherapy and/or antidepressant medications may help relieve depression.
Prevention
Preventing or treating coronary artery disease may help prevent a heart attack.
- Maintain a healthy weight.
- Begin a safe exercise program with the advice of your doctor.
- If you smoke, quit.
- Eat a healthful diet, one that is low in saturated fat and rich in whole grains, fruits, and vegetables.
- Appropriately treat high blood pressure and/or diabetes.
- Ask your doctor about taking a small, daily dose of aspirin. It has been shown to decrease the risk of heart attack.
- Ask your doctor about taking cholesterol-lowering medications.
- Ask your doctor about taking nitrate medications if you have angina due to coronary artery disease.
- Ask your doctor about taking medication to improve heart function, such as:
- Beta-blockers
- Ace-inhibitors
- Calcium-channel blockers
- Digitalis-type drugs
Organizations
American Heart Association
http://www.americanheart.org
American Medical Association
http://www.medem.com
SOURCES:
Conn's Current Therapy 2001, 53rd ed. W. B. Saunders Company, 2001.
American Heart Association
American Medical Association
Last reviewed June 2001 by Medical Review Board