What is a heart attack (myocardial infarction)?
A heart attack, or myocardial infarction, occurs when one or more regions
of the heart muscle experience a severe or prolonged lack of oxygen caused
by blocked blood flow to the heart muscle.
The blockage is often a result of atherosclerosis-a buildup of plaque composed
of fat deposits, cholesterol, and other substances. When a plaque ruptures,
a blood clot quickly forms. The blood clot is the actual cause of the
If the blood and oxygen supply is cut off, muscle cells of the heart begin
to suffer damage and start to die. Irreversible damage begins within 30
minutes of blockage. The result is dysfunction of the heart muscle in
the area affected by the lack of oxygen or cell death.
What are the risk factors for heart attack?
There are two types of risk factors for heart attack, including the following:
Inherited (or genetic)
Inherited or genetic risk factors are risk factors you are born with that
cannot be changed, but can be improved with medical management and lifestyle changes.
Acquired risk factors are caused by activities that we choose to include
in our lives that can be managed through lifestyle changes and clinical care.
Inherited (genetic) factors: Who is most at risk?
People with inherited hypertension (high blood pressure)
People with inherited low levels of HDL (high-density lipoproteins), high
levels of LDL (low-density lipoprotein) blood cholesterol or high levels
People with a family history of heart disease (especially with onset before age 55)
Aging men and women
People with type 1 diabetes
Women, after the onset of menopause (generally, men are at risk at an earlier
age than women, but after the onset of menopause, women are equally at risk)
Acquired risk factors: Who is most at risk?
People with acquired hypertension (high blood pressure)
People with acquired low levels of HDL (high-density lipoproteins), high
levels of LDL (low-density lipoprotein) blood cholesterol, or high levels
People who are under a lot of stress
People who drink too much alcohol
People who lead a sedentary lifestyle
People overweight by 30 percent or more
People who eat a diet high in saturated fat
People with type 2 diabetes
A heart attack can happen to anyone-it is only when we take the time to
learn which of the risk factors apply to us, specifically, can we then
take steps to eliminate or reduce them.
Managing heart attack risk factors
Managing your risks for a heart attack begins with:
Examining which of the risk factors apply to you, and then taking steps
to eliminate or reduce them.
Becoming aware of conditions like hypertension or abnormal cholesterol
levels, which may be "silent killers."
Modifying risk factors that are acquired (not inherited) through lifestyle
changes. Consult your doctor as the first step in starting right away
to make these changes.
Consulting your health care provider soon to determine if you have risk
factors that are genetic or inherited and cannot be changed, but can be
managed medically and through lifestyle changes.
What are the warning signs of a heart attack?
The following are the most common symptoms of a heart attack. However,
each individual may experience symptoms differently. Symptoms may include:
Severe pressure, fullness, squeezing, pain and/or discomfort in the center
of the chest that lasts for more than a few minutes
Pain or discomfort that spreads to the shoulders, neck, arms, or jaw
Chest pain that increases in intensity
Chest pain that is not relieved by rest or by taking nitroglycerin
Chest pain that occurs with any/all of the following (additional) symptoms:
Sweating, cool, clammy skin, and/or paleness
Shortness of breath
Nausea or vomiting
Dizziness or fainting
Unexplained weakness or fatigue
Rapid or irregular pulse
Although chest pain is the key warning sign of a heart attack, it may be
confused with indigestion, pleurisy, pneumonia, or other disorders.
The symptoms of a heart attack may resemble other medical conditions or
problems. Always consult your health care provider for a diagnosis.
Responding to heart attack warning signs
If you or someone you know exhibits any of the above warning signs, act
immediately. Call 911, or your local emergency number.
Treatment for a heart attack
The goal of treatment for a heart attack is to relieve pain, preserve the
heart muscle function, and prevent death.
Treatment in the emergency department may include:
Intravenous therapy such as nitroglycerin and morphine.
Continuous monitoring of the heart and vital signs.
Oxygen therapy improves oxygenation to the damaged heart muscle.
Pain medication decreases pain, and, in turn, decreases the workload of
the heart, thus, the oxygen demand of the heart decreases.
Cardiac medication, such as beta-blockers, promote blood flow to the heart,
improve the blood supply, prevent arrhythmias, and decrease heart rate
and blood pressure.
Fibrinolytic therapy is the intravenous infusion of a medication which
dissolves the blood clot, thus, restoring blood flow.
Antithrombin/antiplatelet therapy is used to prevent further blood clotting.
Antihyperlipidemics are medications used to lower lipids (fats) in the
blood, particularly Low Density Lipid (LDL) cholesterol. Statins are a
group of antihyperlipidemic medications, and include simvastatin (Zocor),
atorvastatin (Lipitor), and pravastatin (Pravachol), among others. Bile
acid sequestrants-colesevelam, cholestyramine, and colestipol-and nicotinic
acid (niacin) are two other types of medications that may be used to reduce
Additional procedures to restore coronary blood flow may be used. Those
Coronary angioplasty. With this procedure, a balloon is used to create a bigger opening in the
vessel to increase blood flow. This is often followed by the insertion
of a stent into the coronary artery to help keep the vessel open. Although
angioplasty is performed in other blood vessels elsewhere in the body,
percutaneous coronary intervention (PCI) refers to angioplasty in the
coronary arteries to permit more blood flow into the heart. PCI is also
called percutaneous transluminal coronary angioplasty (PTCA). There are
several types of PTCA procedures, including:
Balloon angioplasty. A small balloon is inflated inside the blocked artery to open the blocked area.
Coronary artery stent. A tiny coil is expanded inside the blocked artery to open the blocked
area and is left in place to keep the artery open.
Atherectomy. The blocked area inside the artery is cut away by a tiny device on the
end of a catheter.
Laser angioplasty. A laser used to "vaporize" the blockage in the artery.
Coronary artery bypass. Most commonly referred to as simply "bypass surgery" or CABG
(pronounced "cabbage"), this surgery is often performed in people
who have angina (chest pain) and coronary artery disease (where plaque
has built up in the arteries). During the surgery, a bypass is created
by grafting a piece of a vein above and below the blocked area of a coronary
artery, enabling blood to flow around the obstruction. Veins are usually
taken from the leg, but arteries from the chest or arm may also be used
to create a bypass graft.