(Myocardial Infarction)
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.
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
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:
o Exercise or exertion
o Emotional stress
o Cold weather
o 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 immediately. You need emergency medical care.
Tests may include:
Blood Tests – to look for certain enzymes found in the blood within hours or days after a heart attack. Blood tests will be repeated every 6-8 hours to track the enzymes’ progressive elevation that indicates 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, function, and motion of the heart
Stress Test – records the heart's electrical activity under increased physical demand. A stress test can also be combined with an echocardiography. Patients who cannot exercise may be given a medication intravenously that simulates the effects of physical exertion. A stress test is done usually days or weeks after the heart attack.
Nuclear Scanning – Radioactive material (such as thalium) is injected into a vein and observed as it is absorbed by the heart muscle. Areas with diminished flow, and therefore uptake of the radioactive material, show up as dark spots on the scan.
Electron-beam CT scan (coronary calcium scan, heart scan, CT angiography ) – a type of x-ray that uses a computer to make detailed pictures of the heart, coronary arteries, and surrounding structures. This type of CT scan measures the amount of calcium deposits in the coronary arteries, and based on that and other health information, attempts to determines the risk of heart disease, including heart attacks. The American Heart Association (AHA) published guidelines in 2006 indicating that heart scans are not for everyone and those most likely to benefit from the procedure are patients at intermediate risk of coronary artery disease.
Coronary Angiography – X-rays are taken after a dye is injected into the arteries to look for abnormalities (narrowing, blockage) in the coronary arteries
Treatment
Treatment may include:
• Oxygen
• Pain-killing medications (such as morphine)
• Nitrate medications
• Antiplatelet agents
• Beta-blockers
• Aspirin
• 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.
• Other medicines that may be given along with clot-busting agents (called platelet IIb/IIIa receptor blockers)
• Cholesterol-lowering medications
• Anti-anxiety medications
• ACE inhibitors are also frequently given
There are many different medications that may be given in a combination dependent on a patient’s specific situation. Your doctors will determine which ones are the best for you
Surgery
Surgeries for people with severe blockages in their coronary arteries may include:
• Coronary artery bypass surgery
• 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 .
• Manage stress .
• 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 medication to improve heart function or prevent future heart attacks, such as:
o Beta-blockers
o ACE-inhibitors
o Blood thinning medications
Please remember than when you are taking aspirin, certain painkillers (eg, ibuprofen), if taken together with aspirin, may put you at high risk for gastrointestinal bleeding and also diminish the effectiveness of aspirin.
