Heart Attack
(Acute Myocardial Infarction [AMI]; Myocardial Infarction [MI]; ST-Segment-Elevation MI [STEMI]; Transmural Myocardial infarction)
Definition
A heart attack occurs when blood flow to the heart muscle is interrupted. Oxygen can't get to the heart muscle, causing tissue damage or tissue death.
Heart Attack
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
- Spasm of the coronary arteries
- Development of a blood clot in the coronary arteries
Risk Factors
These factors increase your chance of developing heart attack. Tell your doctor if you have any of these:
- 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
- Anxiety , especially feeling a sense of doom or panic without apparent reason
Unusual symptoms of heart attack (may occur more frequently in women):
- Stomach pain
- Back and shoulder pain
- Confusion
- Fainting
Diagnosis
If you think you are having a heart attack, call 911 right away.
Tests may include:
- Blood tests—to look for certain enzymes found in the blood within hours or days after a heart attack
- 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, changes can show if there is blockage or damage
- Echocardiogram —uses high-frequency sound waves (ultrasound) to examine the size, shape, function, and motion of the heart
- Stress test —records the heart's electrical activity under increased physical stress, usually done days or weeks after the heart attack
- Nuclear scanning—uses radioactive material to show areas of the heart muscle where there is diminished blood flow
- Electron-beam computed tomography (EBCT) —a type of x-ray that uses a computer to make detailed pictures of the heart, coronary arteries, and surrounding structures; may be helpful if you are at immediate risk of coronary artery disease
- Coronary angiography —uses dye and x-rays to look for narrowing or blockage in the coronary arteries
Treatment
Treatment includes:
- Oxygen
- Pain-relief medications (such as morphine)
- Nitrate medications
- Aspirin and other antiplatelet agents
- Beta-blocking and/or ACE inhibitor medications (frequently given)
- Anti-anxiety medications
-
Clot-dissolving agents (thrombolytics)—Within the first six hours after a heart attack, you may be given medications to break up blood clots in the coronary arteries.
- Other medicines that may be given include those that block the function of platelets (called platelet IIb/IIIa receptor blockers).
- Cholesterol-lowering medications (eg, statin drugs)
Surgery
If you have severe blockages, you may need surgery. Surgery includes:
- Coronary artery bypass grafting (CABG)
- Atherectomy
- Balloon angioplasty with or without stenting
According to a review, patients who received CABG had more angina relief and less need for another, similar procedure. This is compared to those who received percutaneous coronary intervention (PCI). PCI involves techniques using balloon angioplasty or coronary stenting .
Physical or Rehabilitative Therapy
During recovery , you may need physical or rehabilitative therapy to help you regain your strength.
Treatment for Depression
You may feel depressed after having a heart attack. Therapy and medication can help relieve depression .
If you have a heart attack, follow your doctor's instructions .
Prevention
Preventing or treating coronary artery disease may help prevent a heart attack.
- Maintain a healthy weight .
- Begin a safe exercise program . Follow your doctor's advice.
- If you smoke, quit .
- Eat a healthful diet . Your diet should be low in saturated fat and rich in whole grains, fruits, and vegetables.
- Treat high blood pressure , diabetes and high cholestrol .
- Manage stress .
-
Ask your doctor about taking a small, daily dose of
aspirin.
- Although most people are able to tolerate such a low dose of aspirin, even this small amount can rarely lead to serious bleeding, particuarly from the gastrointestinal (GI) tract .
- Aspirin may not work as well when combined with other pain medications.
RESOURCES:
American Heart Association
http://www.americanheart.org/
Heart and Stroke Foundation
http://www.heartandstroke.com/
CANADIAN RESOURCES
Heart Healthy Kit: Public Health Agency of Canada
http://www.phac-aspc.gc.ca/
Heart and Stroke Foundation
http://ww2.heartandstroke.ca/
References:
Heart attack. Mayo Clinic website. Available at: http://www.mayoclinic.com/health/heart-attack/DS00094/DSECTION=8 . Updated 2007. Accessed June 29, 2008.
Meier MA, Al-Badr WH, Cooper JV, et al. The new definition of myocardial infarction: diagnostic and prognostic implications in patients with acute coronary syndromes. Arch Intern Med . 2002;162:1585-1589.
Mollet NR, Cademartiri F, van Mieghem CA, et al. High-resolution spiral computed tomography coronary angiography in patients referred for diagnostic conventional coronary angiography. Circulation . 2005;112:2318-2323. Epub 2005 Oct 3.
Rakel RE, Bope ET. Conn's Current Therapy 2001 . 53rd ed. Philadelphia, PA: WB Saunders Company; 2001.
What is a heart attack? American Heart Association website. Available at: http://www.americanheart.org/presenter.jhtml?identifier=3007482 . Accessed June 29, 2008.
Women Physicians Congress. What you need to know about heart disease. American Medical Association website. Available at: http://www.ama-assn.org/ama/pub/category/11021.html . Updated 2008. Accessed June 29, 2008.
11/7/2007 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Bravata DM, Gienger AL, McDonald KM, et al. Systematic Review: The comparative effectiveness of percutaneous coronary interventions and coronary artery bypass graft surgery. Ann Intern Med. 2007 Nov 20. [Epub ahead of print]
7/6/2009 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : Antithrombotic Trialists' (ATT) Collaboration, Baigent C, Blackwell L, et al. Aspirin in the primary and secondary prevention of vascular disease: collaborative meta-analysis of individual participant data from randomised trials. Lancet. 2009;373:1849-1860.
Last reviewed September 2009 by David N. Smith, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.