A heart attack occurs when the flow of blood to the heart is blocked. The blockage is
most often a buildup of fat, cholesterol and other substances, which form a plaque
in the arteries that feed the heart (coronary arteries).
The plaque eventually breaks away and forms a clot. The interrupted blood flow can
damage or destroy part of the heart muscle.
A heart attack, or myocardial infarction (MI), is permanent damage to the heart
muscle. "Myo" means muscle, "cardial" refers to the heart, and "infarction" means
death of tissue due to lack of blood supply.
A heart attack, also called a myocardial infarction, can be fatal, but treatment
has improved dramatically over the years.
Symptoms
Angina: Chest pain or discomfort in the center of the chest; also described as a
heaviness, tightness, pressure, aching, burning, numbness, fullness or squeezing feeling
that lasts for more than a few minutes or goes away and comes back. It is sometimes
mistakenly thought to be indigestion or heartburn or acidity.
Pain or discomfort in other areas of the upper body including the arms, left shoulder,
back, neck, jaw, or stomach
Difficulty breathing or shortness of breath
Sweating or "cold sweat"
Fullness, indigestion, or choking feeling (may feel like "heartburn")
Nausea or vomiting
Light-headedness, dizziness, extreme weakness or anxiety
Rapid or irregular heart beats.
Heart attack symptoms vary
Not all people who have heart attacks have the same symptoms or have the same severity of
symptoms. Some people have mild pain; others have more severe pain. Some people have no
symptoms; for others, the first sign may be sudden cardiac arrest. However, the more
signs and symptoms you have, the greater the likelihood you're having a heart
attack.
Some heart attacks strike suddenly, but many people have warning signs and symptoms
hours, days or weeks in advance. The earliest warning might be recurrent chest pain or
pressure (angina) that's triggered by exertion and relieved by rest. Angina is caused by
a temporary decrease in blood flow to the heart.
Women's Symptoms Sometimes Differ
Although most women and men report symptoms of chest pain with a heart attack, women are
slightly more likely than men to report unusual symptoms. Those who have more vague or
less typical "heart" symptoms have reported the following:
Upper back or shoulder pain
Jaw pain or pain spreading to the jaw
Pressure or pain in the center of the chest
Light headedness
Pain that spreads to the arm
Unusual fatigue for several days
Silent MI
Some people have a heart attack without having any symptoms (a "silent" myocardial
infarction). A silent MI can occur among all patients, though it is more common among
women or people with diabetes. A silent MI may be diagnosed during a routine doctor's
exam.
Do not wait to get help: Time is Muscle
At the first signs of a heart attack, Do not wait for your symptoms to "go away." Early
recognition and treatment of heart attack symptoms can reduce the risk of heart damage
and allow treatment to be started immediately. Even if you're not sure your symptoms are
those of a heart attack, you should still be evaluated.
The best time to treat a heart attack is within one hour of the onset of the first
symptoms. When a heart attack occurs, there's a limited amount of time before
significant and long-lasting damage occurs to the heart muscle. If a large area of the
heart is injured during the heart attack, full recovery becomes much more difficult.
Studies show that the people who have symptoms of a heart attack often delay, or wait to
seek treatment, for longer than seven hours.
Reasons why people wait to get help:
People who delay tend to be older, female, to have a history of angina, high blood
pressure or diabetes. People who delay also consult their family members or try to treat
themselves first before seeking treatment.
Reasons people delay:
They are young and don't believe a heart attack could happen to them
Symptoms are not what they expected
They may deny the symptoms are serious and wait until they go away
They may ask the advice of others, especially family members
They may first try to treat the symptoms them-selves, using antacids
They may think the symptoms are related to other health problems (upset stomach,
arthritis)
They may put the care of others first (take care of children or other family members)
and not want to worry them
Waiting just a couple hours for medical help may limit your treatment options, increase
the amount of damage to your heart muscle, and reduce your chance of survival.
Risk factors
Certain factors contribute to the unwanted buildup of fatty deposits (atherosclerosis)
that narrows arteries throughout your body.
Heart attack risk factors include:
Age: Men age 45 or older and women age 55 or older are more likely to have a
heart attack than are younger men and women.
Tobacco: This includes smoking and long-term exposure to secondhand smoke.
High blood pressure: Over time, high blood pressure can damage arteries that feed
your heart. High blood pressure that occurs with other conditions, such as obesity, high
cholesterol or diabetes, increases your risk even more.
High blood cholesterol or triglyceride levels: A high level of low-density
lipoprotein (LDL) cholesterol (the "bad" cholesterol) is most likely to narrow arteries.
A high level of triglycerides, a type of blood fat related to diet, also increases risk
of heart attack. However, a high level of high-density lipoprotein (HDL) cholesterol
(the "good" cholesterol) lowers risk of heart attack.
Obesity: Obesity is associated with high blood cholesterol levels, high
triglyceride levels, high blood pressure and diabetes. Losing just 10 percent of your
body weight can lower this risk, however.
Diabetes
Metabolic syndrome: This occurs when you have obesity, high blood pressure and
high blood sugar. Having metabolic syndrome makes you twice as likely to develop heart
disease.
Family history of heart attack: If your siblings, parents or grandparents have
had early heart attacks (by age 55 for male relatives and by age 65 for female
relatives), you might be at increased risk.
Lack of physical activity: Being inactive contributes to high blood cholesterol
levels and obesity. People who exercise regularly have better cardiovascular fitness,
including lower high blood pressure.
Stress: You might respond to stress in ways that can increase your risk of a
heart attack.
Illicit drug use: Using stimulant drugs, such as cocaine or amphetamines, can
trigger a spasm of your coronary arteries that can cause a heart attack.
Diagnosis
Ideally, routine visit to the doctor should be done to screen for risk factors that can
lead to a heart attack.
Tests include:
Electrocardiogram (ECG): This first test done to diagnose a heart attack records
the electrical activity of your heart via electrodes attached to your skin, the ECG may
show that a heart attack has occurred or is in progress.
Blood tests: Certain heart proteins (cardiac enzymes –CK-MB and TROPONINS )slowly
leak into your blood after heart damage from a heart attack.
Additional tests
Chest X-ray: An X-ray image of your chest allows your doctor to check the size of
your heart and its blood vessels and to look for fluid in your lungs.
Echocardiogram: Help to identify whether an area of your heart has been damaged
and isn't pumping normally.
Coronary angiogram: A liquid dye is injected into the arteries of your heart
through a long, thin tube (catheter) that's fed through an artery, usually in your leg
or groin, to the arteries in your heart. The dye makes the arteries visible on X-ray,
revealing areas of blockage.
Treatment
Each minute after a heart attack, more heart tissue deteriorates or dies. Restoring blood
flow quickly helps prevent heart damage.
Medications
Medications given to treat a heart attack might include:
Aspirin
Thrombolytics: These drugs, also called clotbusters, help dissolve a blood clot
that's blocking blood flow to your heart. The earlier you receive a thrombolytic drug
after a heart attack, the greater the chance you'll survive and have less heart damage.
Antiplatelet agents: clopidogrel, prasugrel, ticagrelor
Other blood-thinning medications: Heparin, to make your blood less "sticky" and
less likely to form clots. Heparin is given intravenously or by an injection under your
skin.
Pain relievers: You might be given a pain reliever, such as morphine, Fentanyl
Nitroglycerin: This medication, used to treat chest pain (angina), can help
improve blood flow to the heart by widening (dilating) the blood vessels.
Beta blockers: These medications help relax your heart muscle, slow your
heartbeat and decrease blood pressure, making your heart's job easier. Beta blockers can
limit the amount of heart muscle damage and prevent future heart attacks.
ACE inhibitors: These drugs lower blood pressure and reduce stress on the heart.
Statins: These drugs help control your blood cholesterol.
In addition to medications, you might have one of these procedures to treat your heart
attack:
Coronary angioplasty and stenting: In this procedure, also known as percutaneous
coronary intervention (PCI), doctors insert a long, thin tube (catheter) that's passed
through an artery in the groin or wrist to a blocked artery in the heart. If you've had
a heart attack, this procedure is often done immediately after a cardiac
catheterization, a procedure used to find blockages.
This catheter has a special balloon that, once in position, is briefly inflated to open
a blocked coronary artery. A metal mesh stent might then be inserted into the artery to
keep it open long term, restoring blood flow to the heart. Depending on your condition,
you might get a stent coated with a slow-releasing medication to help keep your artery
open.
Coronary artery bypass surgery: In some cases, doctors perform emergency bypass
surgery at the time of a heart attack. If possible, however, you might have bypass
surgery after your heart has had time — about three to seven days — to recover from your
heart attack.
Bypass surgery involves sewing veins or arteries in place beyond a blocked or narrowed
coronary artery, allowing blood flow to the heart to bypass the narrowed section.
Once blood flow to your heart is restored and your condition is stable, you're likely to
remain in the hospital for several days.
