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Heart Attack
What is a heart attack?
Heart attacks (also called coronary attacks) result from coronary heart
disease -- disease of the blood vessels that feed the heart muscle. Coronary
artery disease and ischemic (is-KEM'ik) heart disease are other names for
coronary heart disease.
What causes a heart attack?
A heart attack occurs when the blood supply to part of the heart muscle
itself -- the myocardium (mi"o-KAR'de-um) -- is severely reduced or stopped. The
medical term for heart attack is myocardial infarction (mi"o-KAR'de-al
in-FARK'shun). The reduction or stoppage happens when one or more of the
coronary arteries supplying blood to the heart muscle is blocked. This is
usually caused by the buildup of plaque (deposits of fat-like substances) due to
atherosclerosis (ath"er-o-skleh-RO'sis). The plaque can eventually burst, tear
or rupture, creating a "snag" where a blood clot forms and blocks the artery.
This leads to a heart attack. A heart attack is also sometimes called a
coronary thrombosis (throm-BO'sis) or coronary occlusion
(o-KLOO'zhun).
If the blood supply is cut off for more than a few minutes, muscle cells
suffer permanent injury and die. This can kill or disable someone, depending on
how much heart muscle is damaged.
Sometimes a coronary artery temporarily contracts or goes into spasm. When
this happens the artery narrows and blood flow to part of the heart muscle
decreases or stops. We're not sure what causes a spasm. But a spasm can occur in
normal-appearing blood vessels as well as vessels partly blocked by
atherosclerosis. A severe spasm can cause a heart attack.
How Can I Reduce My Chances of a Heart Attack?
The American Heart Association has identified six key
risk factors people can treat or modify to reduce their risk of a heart attack.
Addressing these risk factors can have immediate benefits to your overall health
and well being.
Extensive clinical and statistical studies have identified several factors
that increase the risk of coronary heart disease and heart attack. Major
risk factors are those that research has shown significantly increase the risk
of heart and blood vessel (cardiovascular) disease. There are other factors
associated with increased risk of cardiovascular disease, but their significance
and prevalence haven't yet been precisely determined. These are called
contributing risk factors.
The American Heart Association has identified several risk factors. Some of
them can be modified, treated or controlled, and some can't. The more risk
factors you have, the greater your chance of developing coronary heart disease.
Also, the greater the level of each risk factor, the greater the risk. For
example, a person with a total cholesterol of 300 mg/dL has a greater risk than
someone with a total cholesterol of 240 mg/dL, even though everyone with a total
cholesterol greater than 240 is considered high-risk.
What are the major risk factors that can't be changed?
 | Increasing age ? About four out of five people who die of coronary
heart disease are 65 or older. At older ages, women who have heart attacks are
more likely than men are to die from them within a few weeks. |
| Male sex (gender) ? Men have a greater risk of heart attack than
women do, and they have attacks earlier in life. Even after menopause, when
women's death rate from heart disease increases, it's not as great as men's. |
| Heredity (including Race) ? Children of parents with heart
disease are more likely to develop it themselves. African Americans have more
severe high blood pressure than Caucasians and a higher risk of heart disease.
Heart disease risk is also higher among Mexican Americans, American Indians,
native Hawaiians and some Asian Americans. This is partly due to higher rates
of obesity and diabetes. Most people with a strong family history of heart
disease have one or more other risk factors. Just as you can't control your
age, sex and race, you can't control your family history. It's even more
important to treat and control any other risk factors you have. |
What are the major risk factors you can modify, treat or control by changing
your lifestyle or taking medicine?
| Tobacco smoke ? Smokers' risk of heart attack is more than twice
that of nonsmokers. Cigarette smoking is the biggest risk factor for sudden
cardiac death. Smokers have two to four times the risk of nonsmokers. Smokers
who have a heart attack also are more likely to die and die suddenly (within
an hour). Cigarette smoking also acts with other risk factors to greatly
increase the risk for coronary heart disease. People who smoke cigars or pipes
seem to have a higher risk of death from coronary heart disease (and possibly
stroke) but their risk isn't as great as cigarette smokers'. Constant exposure
to other people's smoke increases the risk of heart disease even for
nonsmokers. |
| High blood cholesterol ? As blood cholesterol rises, so does risk
of coronary heart disease.. When other risk factors (such as high blood
pressure and tobacco smoke) are present, this risk increases even more. A
person's cholesterol level is also affected by age, sex, heredity and diet. |
| High blood pressure ? High blood pressure increases the heart's
workload, causing the heart to enlarge and weaken. It also increases your risk
of stroke, heart attack, kidney failure and congestive heart failure. When
high blood pressure exists with obesity, smoking, high blood cholesterol
levels or diabetes, the risk of heart attack or stroke increases several
times. |
| Physical inactivity ? An inactive lifestyle is a risk factor for
coronary heart disease. Regular, moderate-to-vigorous physical activity helps
prevent heart and blood vessel disease. The more vigorous the activity, the
greater your benefits. However, even moderate-intensity activities help if
done regularly and long term. Exercise can help control blood cholesterol,
diabetes and obesity, as well as help lower blood pressure in some people. |
| Obesity and overweight ? People who have excess body fat ?
especially if a lot of it's in the waist ? are more likely to develop heart
disease and stroke even if they have no other risk factors. Excess weight
increases the strain on the heart. It also raises blood pressure and blood
cholesterol and triglyceride (tri-GLIS'er-íd) levels, and lowers HDL ("good")
cholesterol levels. It can also make diabetes more likely to develop. Many
obese and overweight people may have difficulty losing weight. But by losing
10 to 20 pounds, you can help lower your heart disease risk. |
| Diabetes mellitus (di"ah-BE'teez or di"ah-BE'tis meh-LI'tis) ?
Diabetes seriously increases your risk of developing cardiovascular disease.
Even when glucose levels are under control, diabetes greatly increases the
risk of heart disease and stroke. About two-thirds of people with diabetes die
of some form of heart or blood vessel disease. If you have diabetes, it's
extremely important to work with your healthcare provider to manage it and
control any other risk factors you can. |
What other factors contribute to heart disease risk?
| Individual response to stress may be a
contributing factor. Some scientists have noted a relationship between
coronary heart disease risk and stress in a person's life, their health
behaviors and socioeconomic status. These factors may affect established risk
factors. For example, people under stress may overeat, start smoking or smoke
more than they otherwise would. |
| Sex hormones seem to play a role in
heart disease. It's well known that men have more heart attacks than women do
before women reach the age of menopause. Several population studies show that
the loss of natural estrogen as women age may contribute to a higher risk of
heart disease after menopause. If menopause is caused by surgery to remove the
uterus and ovaries, the risk of heart attack rises sharply. If menopause
occurs naturally, the risk rises more slowly. |
| Hormones also affect blood cholesterol.
Female hormones tend to raise HDL ("good") cholesterol and lower total blood
cholesterol. Male hormones do the opposite. |
| If you've had a natural or surgical menopause,
you may be considering estrogen replacement therapy (ERT) or hormone
replacement therapy (HRT). ERT and HRT may increase your risk of some diseases
and health conditions. Your healthcare provider can give you more information
and help you make the best choice. |
| The early forms of birth control pills,
with higher doses of estrogen and progestin (pro-JES'tin), increased a woman's
risk of heart disease and stroke. That's especially true for older women who
smoked. Newer, lower-dose oral contraceptives carry a much lower risk of
cardiovascular disease, except for women who smoke or have high blood
pressure. |
| If a woman taking oral contraceptives has other risk factors (and
especially if she smokes), her risk of developing blood clots and having a
heart attack goes up. It rises even more after age 35. If you take birth
control pills, get your blood pressure, triglyceride and glucose levels
checked yearly. |
| Drinking too much alcohol can raise blood pressure, cause heart failure
and lead to stroke. It can contribute to high triglycerides, cancer and other
diseases, and produce irregular heartbeats. It contributes to obesity,
alcoholism, suicide and accidents. |
| The risk of heart disease in people who drink moderate amounts of alcohol
(an average of one drink for women or two drinks for men per day) is lower
than in nondrinkers. One drink is defined as 1-1/2 fluid ounces (fl oz) of
80-proof spirits (such as bourbon, Scotch, vodka, gin, etc.), 1 fl oz of
100-proof spirits, 4 fl oz of wine, or 12 fl oz of beer. It's not recommended
that nondrinkers start using alcohol or that drinkers increase the amount they
drink. |
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