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Heart
Attack and Acute Coronary Syndrome
*
Please note that most treatment modalities listed below are based
on conventional medicine. PreventDisease.com does advocate the
use of any pharmaceutical drug treatments. Long-term drug therapy
is detrimental to human health. All drug information is for your
reference only and readers are strongly encouraged to research
healthier alternatives to any drug therapies listed.
WHAT
IS A HEART ATTACK (MYOCARDIAL INFARCTION) AND WHAT CAUSES IT?
The heart is
the human body's hardest working organ. Throughout life it continuously
pumps blood enriched with oxygen and vital nutrients through a network
of arteries to all parts of the body's tissues. In order to perform
the arduous task of pumping blood to the rest of the body, the heart
muscle itself needs a plentiful supply of oxygen-rich blood, which
is provided through a network of coronary arteries. These arteries
carry oxygen-rich blood to the heart's muscular walls (the myocardium).
Coronary artery disease is the most common cause of heart attacks,
which occurs when blood flow to the myocardium is interrupted.
In general, in patients with coronary artery disease, the presence
of one of three of the following syndromes suggests different degrees
of severity.
Stable Angina. Angina is the primary symptom of coronary
artery disease and is typically experienced as chest pain. Stable
angina is predictable chest pain and can usually be managed with
life-style measures and medications, such as low-dose aspirin. [
See Box Angina.]
Acute Coronary Syndromes. Acute coronary syndromes are severe
and sudden heart conditions that require aggressive treatment but
have not developed into a full blown heart attack. Acute coronary
syndromes include the following:
- Unstable
angina. Unstable angina is a much more serious situation and
is often an intermediate stage between stable angina and a heart
attack.
- Non Q-wave
myocardial infarction. (This latter condition is diagnosed when
blood tests and ECGs suggest a developing heart attack. In such
cases, injury in the arteries appears to be less severe than
with a full-blown heart attack.)
Heart Attack.
The full blown heart attack occurs when blood flow is blocked
and tissue death occurs from loss of oxygen, severely damaging the
heart. In such cases, an injury known as an infarct occurs,
or in other words, a myocardial infarction , more commonly
known as a heart attack.
The
Process of Atherosclerosis
Coronary artery
disease is the end result of a complex process called atherosclerosis
(commonly called "hardening of the arteries"). This causes blockage
of arteries ( ischemia) and prevents oxygen-rich blood from
reaching the heart. There are many steps in the process leading
to atherosclerosis and some are not fully understood.
Increasingly, however, researchers are studying the interactions
between cholesterol and processes known as oxidation and
the inflammatory response :
Cholesterol and Lipoproteins. The story begins with cholesterol
and sphere shaped bodies called lipoproteins that transport
cholesterol.
- Cholesterol
is a white, powdery nutrient that is found in all animal cells
and in animal-based foods. It is critical for many functions,
but under certain conditions cholesterol can have harmful effects.
- The lipoproteins
that transport cholesterol are referred to by their size. The
most commonly known are low-density lipoproteins (LDL) and high
density lipoproteins (HDL). LDL is often referred to as the
"bad" cholesterol and HDL as the "good" cholesterol.
Oxidation.
The damaging process called oxidation is an important trigger in
the atherosclerosis story.
- Oxidation
is a chemical process in the body caused by the release of unstable
particles known as oxygen-free radicals . It is one of
the normal processes in the body, but under certain conditions
(such as exposure to cigarette smoke or other environment stresses)
these free radicals are over-produced.
- In excess
amounts, they can be very dangerous, including damaging cells
and even effecting genetic material.
- For example,
in the case of heart disease, free radicals are released in
artery linings and oxidize low-density lipoproteins (LDL).
- The oxidized
LDL is the basis for cholesterol build-up on the artery walls.
Inflammatory
Response. For the arteries to harden there must be a persistent
reaction in the body that causes on-going harm. Researchers now
believe that this reaction is an immune process known as the inflammatory
response.
- The injuries
to the arteries during oxidation signal the immune system to
release white blood cells (particularly those called neutrophils
and macrophages) at the site. These factors initiate
the inflammatory response.
- Macrophages
literally "eat" foreign debris, in this case oxidized LDL cholesterol.
- The process
converts LDL cholesterol into foamy cells that attach to the
smooth muscle cells of the arteries. The cholesterol becomes
mushy and accumulates on artery walls.
- Over time
the cholesterol dries and forms a hard plaque, which
causes further injury to the walls of the arteries.
- In response
to this additional harm, the immune system releases other factors
called cytokines. These are powerful inflammatory molecules
that attract more white blood cells and perpetuate the whole
cycle, causing persistent injury to the arteries.
Blockage in
the Arteries. Eventually these calcified (hardened) arteries
become narrower (a condition known as stenosis).
- As this
narrowing and hardening process continues, blood flow slows
and prevents sufficient oxygen-rich blood from reaching the
heart.
- Such oxygen
deprivation in vital cells is called ischemia. When it
affects the coronary arteries, it causes injury to the tissues
of the heart.
- Injured
inner vessel walls also fail to produce enough nitric oxide
, a substance critical for maintaining blood vessel elasticity.
- These
narrow and inelastic arteries not only slow down blood flow
but they also become vulnerable to injury and tears.
The End Result:
Heart Attack. Heart attack can occur as a result of one or two
effects of atherosclerosis:
(1) If the artery becomes completely blocked and ischemia becomes
so extensive that oxygen-bearing tissues around the heart die.
(2) If the plaque itself develops fissures or tears. Blood platelets
adhere to the site to seal off the plaque and a blood clot (thrombus)
forms. A heart attack can then occur if the formed blood clot completely
blocks the passage of oxygen-rich blood to the heart.
WHAT
ARE THE SYMPTOMS OF A HEART ATTACK?
Common
Heart Attack Symptoms
Any unusual chest
pain, angina, or other suspicious symptoms that do not clear up
with medications is a signal to go to the hospital in people with
known heart disease. (It should be noted, however, that only about
20% of heart attacks follow long-standing angina.) The sooner one
is treated for a heart attack the better the outcome. ANYONE
WHO BELIEVES THEY ARE HAVING A HEART ATTACK SHOULD NOT HESITATE
TO CALL THE EMERGENCY MEDICAL SYSTEM. [ See Box Angina.]
Some signs to watch out for are as follows:
- Pain experienced
as a crushing weight against the chest, which is accompanied
by profuse sweating. The pain may radiate to the left shoulder
and arm, the neck or jaw, and even infrequently to the right
arm. The arm may even be numb.
- Chest
pain, usually precipitated by exercise or stress, that does
not clear up when medications are taken or when resting.
- Mild chest
pain with unexplained fatigue and ill health. Depression may
be present. In patients with known heart disease, such symptoms
have sometimes been reported within a month of a heart attack.
It should be
noted, however, that degree of pain and the specific symptoms before
a heart attack vary greatly among individuals.
- Some people
may feel severe pain; others might feel only a tingling sensation.
Some people may only have a sense of fullness, squeezing, or
pressure in the chest.)
- A feeling
of indigestion or heartburn is common, as are nausea and vomiting.
- Some people
report a great fear of impending death, a phenomena known as
angor animi.
Atypical
Symptoms in Specific Populations
About one-third
of all heart attack patients do not have chest pain at all, putting
them at much higher risk for a misdiagnosis. Women and the elderly
are particularly more likely to have atypical symptoms (although
they can certainly have classic heart attack symptoms as well.)
- A 2000
study suggested that heart attacks might go undiagnosed in people
over 65 who do not have a history of angina or heart failure.
Any older person with unexplained weakness, a rapid heart beat,
difficulty in breathing, or a sudden drop in blood pressure
should be evaluated for a heart problem.
- Symptoms
of angina in women are also often not typical. Before a heart
attack, women are more likely than men to be nauseous and experience
pain high in the abdomen or chest. Their first symptom may be
extreme fatigue after physical activity rather than chest pain.
Chest pain in women is also more likely to be caused by non-heart
problems than the same symptom in men. Because of these reasons,
women are less likely than men to be tested aggressively for
serious heart problems when they enter the emergency room.
Actions
that the Patient Should Take at the Onset of Symptoms
Individuals who
experience symptoms of a heart attack should take the following
actions:
For angina patients, take one nitroglycerin dose either as an
under-the-tongue tablet or in spray form at the onset of symptoms.
Take another dose every five minutes up to three doses or when the
pain is relieved, whichever comes first.
Call 911 or the local emergency number. This should be the
first action taken if angina patients continue to experience chest
pain after taking the full three doses of nitroglycerin. Anyone
who has heart disease or risk factors for it and experiences heart
attack symptoms should contact emergency services. It should be
noted that only 20% of heart attacks occur in patients with long-standing
angina.
The patient should chew an aspirin and be sure that emergency
health providers are informed of this so an additional dose isn't
given.
Chest pain sufferers should go immediately to the nearest emergency
room, preferably traveling by ambulance. They should not drive themselves.
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ANGINA
Angina
is the primary symptom of coronary artery disease and, in
severe cases, of a heart attack. It is typically experienced
as chest pain and occurs when the heart muscle doesn't get
as much blood (hence as much oxygen) as it needs for a given
level of work (ischemia). Angina is usually referred to as
one of two conditions:
- Stable
(predictable).
- Unstable
Angina (less predictable and a sign of a more serious
situation).
Angina
itself is not a disease. Much evidence exists, in fact, that
onset of angina less than 48 hours before a heart attack may
be protective, possibly by conditioning the heart to resist
the damage resulting from the attack.
Angina may be experienced in different ways and can be mild,
moderate, or severe:
-
It is often reported as a dull, heavy pressure that may
resemble a crushing object on the chest.
-
Pain often radiates to the neck, jaw, or left shoulder
and arm.
-
Less commonly, patients report mild burning chest discomfort,
sharp chest pain, or pain that radiates to the right arm
or back.
-
Sometimes a patient experiences shortness of breath, fatigue,
or palpitations instead of pain.
-
The intensity of the pain does not always relate to the
severity of the medical problem. Some people may feel
a crushing pain from mild ischemia, while others might
experience only mild discomfort from severe ischemia.
-
Some people have also reported a higher sensitivity to
heat on the skin with the onset of angina.
-
Angina can also be precipitated by large meals, which
place an immediate demand upon the heart for more oxygen.
Stable
Angina. Stable angina is predictable chest pain. Although
less serious than unstable angina, it can be extremely painful.
It is usually relieved by rest and responds well to medical
treatment (typically nitroglycerin).
Any event that increases oxygen demand can cause an angina
attack. Some typical triggers include the following:
-
exercise,
-
cold weather,
-
emotional tension, or
-
large meals.
Angina
attacks can occur at any time during the day, but a high proportion
seems to take place between the hours of 6:00 AM and noon.
Unstable Angina. Unstable angina is a much more serious
situation and is often an intermediate stage between stable
angina and a heart attack, in which an artery leading to the
heart (a coronary artery) becomes completely blocked. A patient
is usually diagnosed with unstable angina under one or more
of the following conditions:
-
Pain awakens a patient or occurs during rest.
-
A patient who has never experienced angina has severe
or moderate pain during mild exertion (walking two level
blocks or climbing one flight of stairs).
-
Stable angina has progressed in severity and frequency
within a two-month period, and medications are less effective
in relieving its pain.
Prinzmetal's
Angina. A third type of angina, called variant or Prinzmetal's
angina, is caused by a spasm of a coronary artery. It almost
always occurs when the patient is at rest. About two-thirds
of people with it have severe atherosclerosis in at least
one major blood vessel. Irregular heartbeats are common, but
the pain is generally relieved immediately with standard treatment.
Silent Ischemia. Some people with severe coronary artery
disease do not experience angina pain, a condition known as
silent ischemia , which some experts attribute to abnormal
processing of heart pain by the brain. This is a dangerous
condition because patients have no warning signs of heart
disease. In one study, people with silent ischemia experienced
much higher complication and mortality rates than those with
anginal pain. (Angina pain may actually protect the heart
by conditioning it before a heart attack.)
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HOW
SERIOUS IS A HEART ATTACK?
Severity
of a Heart Attack
In 2001, an estimated
650,000 Americans will suffer a first heart attack and 450,000 will
have a recurrent episode. Heart attacks may be rapidly fatal, may
evolve into a chronic disabling condition, or may lead to full recovery.
They will be fatal in about 220,000 of patients. It should be noted,
however, that 12,400,000 people who have had a heart attack, angina,
or both are alive today.
The rate of hospitalization for a first heart attack has not changed
significantly over the past few years. (In fact, it has increased
in African American women.) On the positive side, however, improved
treatments have significantly reduced mortality rates and rehospitalizations.
About 88% of people under age 65 can expect to return to work.
Higher Risk Individuals. A heart attack is always more serious
in certain people:
- Elderly
(particularly those who are thinner).
- Women
have a higher mortality rate after a heart attack than men do.
- People
with a history of heart disease or risk factors for heart disease.
- People
with heart failure.
- People
with diabetes.
- People
on long-term dialysis.
Factors that
Increase Severity. The presence of other conditions during
a heart attack can contribute to a poorer outlook:
- Arrhythmias
(disturbed heart rhythms). A dangerous arrhythmia called ventricular
fibrillation is a major cause of short-term death from heart
attack. Such arrhythmias are more likely to occur within the
first four hours and are associated with a high mortality rate.
(Patients who are successfully treated, however, have the same
long-term prognosis as those who do not experience such arrythmias.)
- Signs
of severe physical damage to the heart.
- Shock.
This very dangerous condition is associated with very low blood
pressure, reduced urine levels, and cellular abnormalities.
Shock occurs in about 7% of heart attacks. The incidence has
not declined over the past years, although its survival rates
have improved.
- Heart
block, also called atrioventricular (AV) block, is a condition
in which the electric conduction of nerve impulses to specialized
muscles in the heart is slowed or interrupted. Although heart
block is dangerous, it can be treated effectively with a pacemaker,
and it rarely causes any long-term complications in patients
who survive it.
Long-term
Outlook
The long-term
prognosis for both length and quality of life after a heart attack
depends on its severity and the preventive measures taken afterward.
Within six years of a heart attack, 18% of men and 35% of women
have a recurrent attack. And, about 22% of men and 46% of women
develop heart failure.
Although at this time no tests can reliably predict whether another
heart attack will occur, experts estimate that up to 30% of fatal
attacks and many follow-up surgeries could be avoided with healthy
lifestyle changes and adherence to medical treatments. Two-thirds
of patients who have suffered a heart attack, however, do not take
the necessary steps to prevent another. [ See Who Is At Risk
for a Heart Attack and What Risk Factors Can Be Managed?, in
this report. ]
WHO
IS AT RISK FOR A HEART ATTACK AND WHAT RISK FACTORS CAN BE MANAGED?
About 12.4 million
Americans currently have heart disease and 1.1 million people are
expected to have a serious heart event this year. An estimated 25%
of all Americans have one or more risk factors for heart disease.
Most risk factors for heart disease are related to lifestyle and
environmental factors. Over the past decades, heart disease declined
in both men and women as they quit smoking and improved dietary
habits. This rate, however, has stabilized in recent years, most
likely because of the dramatic increase in obesity in the US and
other industrialized nations. There have also been minimal changes
in other risk factors, including smoking, sedentary behavior, and
blood pressure control. Some risk factors cannot be changed, including
age, gender, and genetics. Nevertheless, their effects can still
be modified with healthy lifestyle changes.
Reducing Multiple Risk Factors. The risk for heart disease
increases with multiple risk factors, importantly unhealthy cholesterol
or lipid levels, diabetes, obesity, smoking, and hypertension. Conversely,
risk plummets in the absence of multiple risk factors. For example,
a 1999 study found that men and women of all ages who had none of
these risk factors had a risk of dying from heart attack that was
between 77% and 92% lower than those with one or more of them. (The
people with no risk factors also had a lower risk for stroke and
cancer.) Conversely, a 2000 study reported that patients who aggressively
pursued a healthy lifestyle (low-fat diet, stress management, smoking
cessation, moderate aerobic exercise) significantly reduced their
risk for heart attack, cardiac surgery, and death.
Nonmodifiable
Risk Factors
Age. About
85% of people who die from heart disease are over the age of 65.
Gender. Coronary artery disease and heart attacks are much
more common in middle-aged men. Women have, on average, ten to fifteen
more years of heart-disease free life than do men, but as women
age, they catch up to men. Women, in fact, are more likely to have
angina than men are. The American Heart Association reported in
2001 that four million women had angina compared to 2.3 million
men. Younger women with heart disease often do not have the same
symptoms as their male counterparts do and may be less likely to
be diagnose correctly. Studies are now suggesting, however, that
the overall higher mortality rates and the less aggressive treatments
in women with heart disease appear to be due to their older agent
and sicker condition than their male peers at the time of a heart
event. (Interestingly, one 1999 study found that although, indeed,
women with unstable angina were treated less aggressively than men,
when their risk factors were compared head to head, men actually
had a worse long-term outcome.)
Genetic Factors . Genetics are involved in increasing the
likelihood of developing important risk factors (eg, diabetes, obesity,
and high blood pressure). One genetic variant called apolipoprotein
E4 (ApoE4) affects cholesterol levels, particularly those associated
with heart disease. A 1999 study suggests that it may be a significant
risk factor for coronary artery disease in early middle age. (The
presence of this variant may also be associated with increased risk
for Alzheimer's disease.)
Genetic factors that increase the risk for blood clots are also
associated with high risk for heart disease and heart attack. Of
particular importance are those called factor VII genes that affect
the way blood coagulates.
Ethnicity
African Americans.
In a 1998 analysis, although mortality rates from coronary artery
disease declined between 1987 and 1994 in both Caucasians and African
Americans, they did not decline significantly in African Americans.
Of all major ethnic groups, African American women face the highest
risk for death from heart disease, and their rate of heart attacks
is increasing. (Mortality rates in men do not differ much by race.)
African Americans face a number of biologic and social dangers to
their hearts:
- They have
a higher prevalence of diabetes and hypertension than do Caucasians.
- They tend
to have poorer diets, higher stress levels, and lack of access
to health care.
- All African
Americans face discrimination, but women may be at particular
risk for unequal treatment. In one study in which female actors
portrayed heart patients, African American women were 60% less
likely to receive aggressive (and expensive) diagnostic tests
than African American men or any Caucasians, even though they
presented with similar symptoms.
- While
African Americans comprise 13% of the US population, African
Americans have comprised only 2% to 9% of subjects in most of
the major research trials, and so knowledge about their specific
risks is limited.
- Some African
Americans with coronary artery disease appear to have a genetic
trait that increases the danger of triglycerides, which may
be particularly hazardous in women.
- One study
found that African Americans produce less nitric oxide in response
to stress; this substance is critical for opening blood vessels
and increasing blood flow.
Other Groups.
Native American men have a lower risk for heart disease than
Caucasian men, and Hispanics have the lowest risk for heart disease
of all major American population groups.
Cholesterol
and Other Lipids
Cholesterol.
High cholesterol levels are strong risk factors for heart disease,
particularly when the harmful type known as low-density lipoprotein
(LDL) cholesterol is elevated. The higher the cholesterol, the greater
the risk. For example, according to a 2000 study, men with cholesterol
levels over 240 mg/dl have a risk that is 2.15 to 3.63 times higher
than those whose cholesterol is below 200.
Triglycerides. Triglycerides are made up of fatty acid molecules
and are the basic chemicals in animal and plant fats. Evidence now
suggests that these molecules may be major trouble-makers for the
heart. Some evidence also suggests that high triglycerides are risk
factors for heart disease on their own regardless of cholesterol
levels.
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Cholesterol
Goals
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Total
Cholesterol Goals
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LDL
Goals
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HDL
Goals
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Triglyceride
Goals
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200 mg/dl or less. (One study suggested that the ideal cholesterol
goal for older people is between 200 and 220. There is a heart
risk below and above these levels.)
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160 mg/dL or less. (People with two or more risk factors for
heart disease should aim for LDL levels of 130 mg/dl or below.
People with existing heart disease should aim for LDL levels
of below 100 mg/dl.*)
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35 mg/dL or more. (Some experts suggest higher goals, 45 for
men and 50 for women, with everyone aiming for about 60.)
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200 mg/dL or less. (Evidence is suggesting that levels over
only 100 may predict an increased risk for heart disease.)
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*Risk factors for heart disease include a family history of
heart problems, smoking, high blood pressure, diabetes, being
older (over 45 for men and 55 for women), and having HDL levels
below 35 mg/dl. |
Other Lipids. Elevated levels of other fatty molecules (lipids)
are also now thought to be important indicators of heart disease
risk. They include lipoprotein (a) and apolipoprotein A-1 and B.
Apolipoprotein B, for example, may actually turn out to be a very
accurate indicator of heart disease risk in women. ApoE4, a genetic
form of another apolipoprotein, is associated with Alzheimer's disease
and is also under investigation for a role in heart disease. [For
more information, see the Reports #23, Cholesterol
and #43, Heart Healthy Diet .]
High
Blood Pressure
High blood pressure,
or hypertension, has long been a proven cause of coronary artery
disease. Blood pressure is categorized as:
- Optimal
(below 120/80 mm Hg).
- Normal
(between 120/80 and 130/85 mm Hg).
- High normal
(between 130/85 and 139/89). (Some studies indicate that high
normal puts one at higher risk for heart events and stroke,
although others suggest this risk exists primarily in people
with diabetes.)
- Hypertension,
or high blood pressure (140/90). [For more information, see
the Report #14, High Blood Pressure
.]
Obesity
and Overweight
Obesity is related
to hypertension, diabetes, abnormal cholesterol levels, and lack
of exercise, all conditions contributing to heart attack risk. Obesity
in children is a greater risk for future heart trouble than a family
history of heart disease. People who are overweight in middle age
may still not completely reduce their risk for coronary artery disease
later in life, even if they lose excess weight. Abdominal obesity
(the "beer belly") poses a particular risk. Obesity is determined
by measurement of body fat, not merely body weight.
People might be over the weight limit for normal standards, but
if they are very muscular with low body fat, they are not obese.
Others might be normal or underweight, but still have excessive
body fat. The current best single gauge for body fat is a measurement
called body mass index (BMI). It is derived by a series of calculations:
- Multiply
one's weight in pounds by 703.
- Divide
that answer by one's height in inches.
- Divide
that answer once again by height in inches. The resulting number
is the BMI.
Current federal
and WHO guidelines define overweight as a BMI of 25 to 29.9 and
obesity as a BMI of 30 or greater.
[For more information, see the Report #53,
Weight Control and Diet .]
Sedentary
Lifestyle and Exercise
People who are
sedentary are almost twice as likely to suffer heart attacks as
are people who exercise regularly. Regular moderate aerobic exercise
benefits the heart in many ways. For instance, brisk walking has
the following advantages:
- Lowers
the heart rate and blood pressure.
- Raises
HDL ("good") cholesterol.
- Lowers
blood sugar levels.
- Opens
up the blood vessels and, in combination with a healthy diet,
may improve blood clotting factors.
- Reduces
stress and improves mood.
Some studies
suggest that for the greatest heart protection, it is not the duration
of the exercise that counts but the total daily amount of
energy expended. Therefore, the best way to exercise may be in multiple
short bouts of intense exercise. Even elderly people with unstable
angina or who had a previous heart attack can benefit from a structured
exercise program. Exercises that train and strengthen the chest
muscles may also prove to be very important for patients with angina.
It should be noted that sudden strenuous exercise (such as snow
shoveling and mowing lawns) puts such people at risk for angina
and heart attack. Activities that involve raising the arms above
the head may also be risky. Patients with angina should never exercise
shortly after eating.
People with risk factors for heart disease should seek medical clearance
and a detailed exercise prescription. And all people, including
healthy individuals, should listen carefully to their bodies for
signs of distress as they exercise. [ See the
Report #29 Exercise.]
Diabetes
and Insulin Resistance
Heart attacks
account for 60% and strokes for 25% of deaths in all diabetics.
A 1998 study reported that people with type 2 diabetes and no history
of heart disease have the same seven-year risk for a heart attack
as nondiabetics with heart disease.
Long-term insulin resistance, even without type 2 diabetes, appears
to have significant damaging effects on the heart. This condition
occurs when insulin levels are normal to high but the body is unable
to use the insulin to regulate metabolism of blood sugar and to
store it for energy. In such cases, the body compensates by increasing
insulin levels (hyperinsulinemia), which in turn increases triglyceride
levels and reduces HDL cholesterol. Normally, insulin stimulates
the release of two substances, endothelin and nitric oxide, that
are important in keeping arteries elastic and open. Insulin resistance
may cause an imbalance in these substances. [For more information,
see the Reports #9, Diabetes: Type I or
#60, Diabetes: Type II .]
Smoking
Smokers in their
thirties and forties have a heart-attack rate that is five times
higher than their nonsmoking peers. Cigarette smoking may be directly
responsible for at least 20% of all deaths from heart disease, or
about 120,000 deaths annually. Smoking cigars may increase the risk
of early death from heart disease, although evidence is much stronger
for cigarette smoking.
Specific Effects on the Heart. Its damaging effects on the
heart are multifold:
- Smoking
lowers HDL levels (the so-called good cholesterol) even in adolescents.
- It causes
deterioration of elastic properties in the aorta, the largest
blood vessel in the body, and increases the risk for blood clots.
- It increases
the activity of the sympathetic nervous system (which regulates
the heart and blood vessels).
- Tobacco
smoke may increase cardiovascular disease in women through an
effect that reduces estrogen levels.
Effects of
Second-Hand Smoke. Studies continue to confirm the dangers of
second-hand smoke. Regular exposure to passive smoke is now estimated
to increase the risk of heart disease in the nonsmoker by between
25% and 91%, causing 30,000 to 60,000 deaths each year. [For more
information, see the Report Smoking.]
Eating
Habits
Eating habits
can be protective or dangerous to the heart. Although the best diet
is not clear for each individual, avoiding saturated fats and trans-fatty
acids is recommended for everyone. [ See Box Dietary
Factors and Heart Disease.]
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Dietary Factors and Heart Disease
Diet plays
an important role in the health of the heart. There is no
single diet that suits everyone, but a few general observations
can be made. [ For detailed dietary information, see the
report Heart Healthy Diet .]
Fats
Experts
now believe that fats can have both harmful and beneficial
effects. Whether harmful or beneficial they are still high
in calories:
Harmful Fats. Reducing consumption of saturated fats
and trans-fatty acids is the first essential step in managing
cholesterol levels through diet.
- Saturated
Fats. Saturated fats are found predominantly in animal
products, including meat and dairy products. They are
strongly associated with higher cholesterol levels. Although
certain fatty acids in saturated fats called stearic acids
may have some benefits, there is no simple method for
defining foods that contain them, so, in general, saturated
fats should be avoided. (The so-called tropical oils (palm,
coconut, and cocoa butter) are [also high in saturated
fats. Evidence] is lacking, however, about their effects
on the heart. The countries with the highest palm-oil
intake, Costa Rica and Malaysia also have much lower heart
disease rates and cholesterol levels than Western nations.)
- Trans-fatty
Acids. Trans-fatty acids are manufactured fats created
during a process called hydrogenation, which is aimed
at stabilizing polyunsaturated oils to prevent them from
becoming rancid and to keep them solid at room temperature.
They may be particularly dangerous for the heart and may
pose a risk for certain cancers. Some experts believe
that these partially hydrogenated fats are even worse
than saturated fats because they both increase LDL and
reduce HDL cholesterol levels and may have harmful effects
on the linings of the arteries. One study of 80,000 nurses
reported that women whose total fat consumption was 46%
of total caloric intake had no greater risk in general
for a heart attack than did those for whom fat represented
30% of calories consumed. Women whose diets were high
in trans-fatty acids, however, had a 53% increased risk
for heart attack compared to those who consumed the least
of those fats. Hydrogenated fats are used in stick margarine
and in many fast foods and baked goods, including most
commercially produced white breads. (Liquid margarine
is not hydrogenated and is recommended.) The FDA has now
required that food labels include information on trans-fatty
acids.
Beneficial
oils: Public attention has mainly focused on the possible
benefits of small amounts of monounsaturated and polyunsaturated
fats found in vegetable oils. Researchers are most interested,
however, in the smaller fatty-acid building blocks contained
in these oils called essential fatty acids. Three important
fatty acids are the essential fatty acids omega-3,
omega-6, and omega-9.
-
Omega-3 fatty acids: They are further categorized as
alpha-linolenic acid and docosahexaenoic and
eicosapentaenoic acids.
Docosahexaenoic
(DHA) and Eicosapentaenoic (EPA) Acids. Fish
oils, which contain docosahexaenoic (DHA) and eicosapentaenoic
acids (EPA), have anti-inflammatory and anti-blood clotting
effects and may be significantly beneficial to the heart.
DHA is the most unsaturated of all fatty acids. These fatty
acids may reduce triglyceride levels and have modest positive
effects on HDL. In patients with high triglyceride levels,
but not in others, omega 3 fatty acids may increase LDL. Overall
cholesterol levels are not affected. DHA appears to have specific
benefits on blood pressure. The International Society for
the Study of Fatty Acids and Lipids, in fact, recommends fish
oil supplements for heart protection. Omega-3 fatty acids
in fish may reduce risks for other disorders, including stroke,
rheumatoid arthritis, asthma, ulcerative colitis, and some
types of cancers.
Alpha-linolenic Acid . Alpha-linolenic acid is a plant
precursor of DHA, which means the body can convert it to DHA.
Sources include canola oil, soybeans, flaxseed, and certain
nuts and seeds (walnut, flax, chia and sometimes pumpkin seed).
Studies have been positive about the effects on the heart
of these oils or foods containing these oils.
-
Omega-6 polyunsaturated fatty acids. Sources are corn,
safflower, soybean, and sunflower oil. PUFA oils containing
omega-6 fatty acids constitute most of the oils consumed
in the US. Some omega-6 fatty acids are important for
health. There is some association with a higher risk for
certain cancer and some chronic diseases with diets high
in omega-6 fatty acids, however.
-
Omega-9 monounsaturated fatty acids: Sources are canola
and olive oil. Extra virgin olive oil has been associated
with lower blood pressure and a 2000 study reported that
it may have specific benefits for people with diabetes
type 2. Of concern is a small study reporting higher concentrations
of LDL in subjects consuming an olive-oil rich diet compared
to those on a sunflower or rapeseed oil rich diet.
Research
suggests that our current Western diet contains an unhealthy
high ratio (10 to 1) of omega-6 to omega-3 fatty acid. Omega-9
fatty acids may also contain chemicals that block harmful
factors found in omega-6 fatty acids. Researchers are finding
then that the most benefits may be found in mixture of all
three fatty acids found in both poly- and monounsaturated
oils, but in modest amounts that do not add too many calories.
Carbohydrates
Meals overly
rich in carbohydrates tend to set off angina attacks, possibly
because they raise insulin levels. One study suggested, in
fact, that in women, sugar may pose an even higher risk for
heart disease than fats do. Whole grains and fresh fruits
and vegetables (particularly dark-colored ones), however,
are very important. They are rich in fiber, vitamins, and
other important nutrients that are heart-protective. Natural
chemicals in cooked tomatoes, garlic, nuts, apples, onions,
wine, and tea also appear to offer protection for the heart.
Protein
Meat
and Fish. For heart protection, one 1999 study suggested
that it didn't matter if you chose fish, poultry, beef, or
pork as long as the meat was lean. (Saturated fat in meat
is the primary danger to the heart.) The fat content of meat
varies depending on the type and cut. It is best to eat skinless
chicken or turkey; the leanest cuts of pork (loin and tenderloin),
veal, and beef are nearly comparable to chicken in calories
and fat and their effect on LDL and HDL levels. It should
be noted, however, that even chicken and lean meat do not
improve cholesterol levels, and, in terms of cardiac health,
fish is a more desirable choice. Much evidence suggests that
eating fish two or three times a week, particularly oily fish
(such as salmon, halibut, swordfish, and tuna) is protective.
Soy. Soy is proving to be a particularly excellent
source of protein. It is rich in both soluble and insoluble
fiber, omega-3 fatty acids, and provides all essential proteins.
A number of studies have indicated that subjects that consume
about 40 grams of soy protein each day reduce LDL and triglycerides
and increase HDL. Powdered soy protein that contains at least
60 mg of isoflavones may provide similar benefits. (Tablets
of individual isoflavones found in soy, however, do not appear
to offer any advantages.)
Antioxidant Vitamins and Supplements
Vitamin
E. Vitamin E may prevent blood clots and the formation
of fatty plaques and cell proliferation on the walls of the
arteries. Experts have hoped that supplements of this vitamin
prove to be protective. However, few studies have offered
any strong support for these hopes. One major 2000 study,
for example, reported that patients who took a natural vitamin
E at 400 IU for four to six years did not gain any protection
against cardiovascular disease. Different vitamin E compounds,
such as gamma tocopherol or tocotrienol, may prove to have
benefits that the standard synthetic supplements (dl alpha
tocopherol) do not, but more research is needed.
Vitamin C. Although in the laboratory, vitamin C has
positive effects on blood vessels, there is no proof that
supplements of vitamin C offer any actual protection against
heart disease. And there is some evidence that high doses
may even speed up existing damaging processes in the arteries.
B Vitamins. Several important studies have demonstrated
a link between deficiencies in the B vitamins folic acid (folate),
B6, and B12 and elevated blood levels of an amino acid homocysteine,
a possible risk factor for atherosclerosis. Folic acid is
particularly potent in reducing homocysteine levels, and folate
deficiencies are associated with a higher risk from heart
disease. (Green vegetables and legumes, enriched cereals and
grains, and orange juice are rich in folate.) It is not clear
yet if taking folate supplements and reducing homocysteine
levels will actually protect against heart disease. Major
studies are under way and small studies are promising. [ See
Homocysteine under Emerging Risk Factors .]
Another important B vitamin is niacin (Vitamin B3), which
improves cholesterol and triglyceride levels.
Note: Studies are continuing to indicate that high doses of
antioxidants supplements, such as vitamins C, E, and beta
carotene, may have pro-oxidant effects that can actually harm
the arteries and incur other damage. [For more information,
see the Report, Vitamins, Carotenoids,
and Phytochemicals .]
|
Stress
and Psychologic Factors
Stress.
Incidents of acute stress have been associated with a higher risk
for serious cardiac events, such as heart rhythm abnormalities and
heart attacks, and even death from such events in people with heart
disease. Most studies have focused on the negative effects of stress
on the hearts of men, particularly from work, but a 2000 study reported
that marital stress (but not work stress) also hurts women's hearts.
Stress may have actual negative physical effects on the heart. [
See the Report #31, Stress .]
Depression. In one 30-year study, men who were clinically
depressed had a greater risk for heart disease and heart attack
than men who were not depressed. This higher risk lasted for decades.
The more severe the depression, the more dangerous to the health.
Some studies have indicated that even mild depression, including
feelings of hopelessness, experienced over many years, may harm
the hearts in people with no early signs of heart disease. A number
of studies have suggested that depression has biologic effects on
the heart, including blood clotting and heart rate. Depression may
also impair a patient's response to medication for heart disease.
(On the other hand hardening of the arteries in the brain may cause
depression, so depression may simply be a marker of severe cardiovascular
disease.)
Anger and Hostility. There have been some reports of an association
between angry temperaments and heart disease. According to a 2000
study on Army personnel, however, psychologic factors (including
depression, anxiety, hostility, and stress) did not appear to have
any effect on hardening of the arteries, the primary cause of coronary
artery disease. And, another 2000 study suggested that anger itself
posed no higher risk to the heart, although outwardly expressed
anger plus low social support did appear to predict progression
of heart disease. [ See the Report
#8, Depression.]
Alcohol
The effects of
alcohol on heart disease varies depending on consumption. Evidence
strongly suggests that light to moderate alcohol consumption (one
or two drinks a day) protects the heart, even in people with type
2 diabetes. The benefits are strongest in people at high risk for
heart disease and may be fairly small in those at low risk. No one
recommends that nondrinkers start using alcohol for health reasons
or that regular drinkers increase their intake. Large amounts of
alcohol can raise blood pressure, trigger irregular heartbeats,
and damage the heart muscle. Binge drinkers have a significantly
higher risk for a cardiac emergency.
Emerging
or Possible Risk Factors for Heart Disease
Homocysteine.
Abnormally high blood levels of the amino acid homocysteine
are strongly linked to an increased risk of coronary artery disease
and stroke. Homocysteine may harm the lining of the arteries and
reduce blood flow. Excessive levels occur with deficiencies of vitamins
B6, B12, and folic acid.
Infectious Agents. Some microorganisms and viruses have been
under suspicion for triggering the inflammation and damage in the
arteries that contributes to heart disease. The primary suspect
has been Chlamydia pneumoniae (a non-bacterial organism that
causes mild pneumonia in young adults). Other organisms under investigation
include H. pylori (the bacteria responsible for peptic ulcers),
and the viruses herpesvirus and cytomegalovirus.
Iron Overload. Iron overload (high levels of iron in the
blood) has been associated with coronary artery disease in animals.
Results of studies on high iron levels in people, however, have
been mixed. In a 2000 study of people with high iron levels, for
example, Caucasian men had no higher mortality risk, but women had
a higher death rate from heart disease and African American men
had higher mortality rates from all causes. And a 2001 study reported
that blood donations (which reduce iron levels) had no protective
effect on heart disease. Most studies have been conducted on Caucasian
men, and none have provided clear proof one way or the other on
the effects of iron on the heart in any group.
Inflammatory Factors. An immune response that produces inflammation
and damage in the arteries (possibly triggered by infection or other
factors) is now strongly associated with heart disease. Specific
inflammatory factors involved in the process may include those called
C reactive protein and fibrinogen.
- Elevated
levels of C-reactive protein strongly predict future heart attacks
in patients with existing heart disease, particularly unstable
angina. Some studies have even suggested that the protein itself
may directly play a role in damage to heart muscles. Nevertheless,
high levels of C-reactive protein may simply be a by-product
of processes involved in heart disease, such as obesity or smoking,
rather than an independent predictor or cause of heart disease.
- High levels
of fibrinogen, a protein that is a central participant in the
clotting process, is also a potential indicator of heart disease.
Periodontal
(Gum) Disease. Some studies have reported a 1.5- to four-fold
risk for heart disease in people with peridontal disease. In one,
85% of heart attack patients had periodontal disease compared to
29% of people who were free of heart disease. The bacteria that
cause periodontitis may stimulate inflammatory factors that cause
blood clots and other proteins that contribute to this higher risk.
On the other hand, gum disease may simply be a common risk factor
among other known risk factors for stroke, including being poor,
African American, older, and overweight.
Oral Contraceptives. Some women who took early forms of
oral contraceptives (OCs), particularly if they smoked, had high
blood pressure, or both, have a higher risk for heart attack and
stroke. Newer forms pose a much lower risk. And, in fact, a 2001
study found no higher risk for a heart attack in women using newer,
low-dose OCs.
Sleep Apnea. Obstructive sleep apnea is a condition in which
tissues in the upper throat collapse at intervals during sleep,
thereby blocking the passage of air. It is often accompanied by
snoring and short, gasping wakefulness. Many risk factors are associated
with both stroke and sleep apnea (obesity, high blood pressure,
a risk for blood clots, and narrowing of the arteries). These factors
may also increase the risk for heart attacks. In one 2001 study,
researchers observed that the higher the number of apneas a patient
had, the higher his risk for heart attack.
Cocaine Use. A 2001 study suggested that one fourth of all
non-fatal heart attacks in people under age 45 were due to regular
cocaine use.
Conditions
Associated with Heart Disease
Some inborn or
natural conditions are not risk factors themselves but have been
associated with a higher incidence of heart disease or its consequences:
- Factors
Before Birth and In Infancy. Low weight at birth and in
the womb has been associated with later heart disease in a few
studies. Some suggest, however, that this may just reflect poor
nutrition in the mother, which appears to affect life-long risk.
A 2000 British study reinforced the idea that pre-birth or other
early events have little significant effect on heart disease
risk in later life.
- Seasonal
Differences. More deaths from heart disease occur in December
and January and fewest in the summertime. Although lower temperatures
and snow shoveling may play a role in some cases, more winter
deaths have been reported even in warm regions. Holiday stress
or fewer daylight hours have been suggested as other reasons
for these higher winter rates.
- Physical
Characteristics. Male pattern baldness, hair in the ear
canals, and creased earlobes are associated with a higher risk
for heart disease in white males. (Interestingly, in African
American men, of these factors, only creased earlobes were associated
with a higher risk in one study.)
- Air
Pollution. A 2000 study suggested that air pollution is
linked to a higher risk of sudden death in patients with heart
problems. It is possible that small particles can affect heart
rhythms, which may be dangerous for people with heart conditions.
WHAT
ARE THE TESTS USED TO DETERMINE A HEART ATTACK?
Electrocardiogram
An electrocardiogram
(ECG or EKG) measures and records the electrical activity of the
heart. Between 25% and 50% of people who suffer from angina or have
silent ischemia, however, have normal ECG readings, and experts
estimate that it may fail to detect 60% of heart attacks.
Recording the Heart Beats. ECGs record wave patterns that
correspond to the contraction and relaxation pattern of the different
parts of the heart. Specific waves seen on an ECG are named with
letters as follows:
- The P
wave is associated with the contractions of the atria
(the two chambers in the heart that receive blood from outside).
- QRS. The
QRS is a series of waves associated with ventricular contractions.
(The ventricles are two major pumping chambers in the heart.)
- T and
U. These waves follow the ventricular contractions.
Physicians will
use a term called the P-Q or P-R interval, which is the time taken
for an electrical impulse to travel from the atria to the ventricle.
The most important wave patterns in diagnosing and determining treatment
for a heart attack are called ST elevations and Q waves.
Elevated ST Segments. Elevated ST segments indicate that
the artery to an area of the heart is blocked and that the full
thickness of the heart muscle is damaged. In most cases patients
go on to develop a full-blown heart attack, medically referred to
as a Q-wave myocardial infarction. ST-elevations are good indicators
for aggressive treatments (thrombolytic drugs or angioplasty) to
reopen blood vessels. In some cases, however, patients with elevated
ST-segments turn out to actually have only non-Q-wave myocardial
infarctions, which are generally less serious conditions [see below].
Non-Elevated ST Segments. Non-elevated ST segments indicate
less complete blockage and occur in about half of patients with
other signs of a heart event. In such cases, laboratory tests are
needed to determine the extent, if any, of heart damage. In general,
one of three following conditions may be present:
- Angina
(blood test results or other tests show no serious problems
and chest pain resolves). Most patients with angina can go home.
- Unstable
angina (blood tests do not show markers for heart attack but
chest pain is persistent). Unstable angina is potentially serious.
- Non Q-wave
myocardial infarction (blood tests suggest a developing heart
attack, but most likely, injury in the arteries is less serious
than with a full-blown heart attack).
Acute coronary
syndrome refers to both unstable angina and non Q-wave myocardial
infarction, because they are treated differently then full-blown
heart attacks. [ See Box Managing
Acute Coronary Syndromes.]
Angiography
Angiography is
an invasive test that may be performed on patients who have very
incapacitating angina that does not respond to medical therapy.
It may be useful in certain cases following a heart attack to assess
treatment success.
- A narrow
tube is inserted into an artery, usually in the leg or arm,
and then threaded up through the body to the coronary arteries.
- A dye
is injected into the tube and an x-ray records the flow of dye
through the arteries.
- This process
provides a map of the coronary circulation, revealing any blocked
areas.
Major complications
include stroke, heart attacks, and kidney damage. These risks are
very low (about 0.1%), however, if the procedure is done in an experienced
medical center (one that performs at least 300 of these operations
every year). Allergic reactions can also occur.
Imaging
Tests
Echocardiograms.
Echocardiograms are useful in patients who are suspected of having
a heart attack but whose EKGs are normal. They are particularly
important to diagnose the extent of damage to the heart muscle
and to diagnose congestive heart failure.
Magnetic Resonance
Imaging (MRI). A very promising investigative approach using
magnetic resonance imaging (MRI) and a contrast material (an injected
dye) can provide images of the entire thickness of the heart muscle
instead of just the surface. It is proving to be accurate enough
to allow prediction of which patients might benefit most from surgical
procedures. This approach is unlikely to be widely available for
some time.
Radionuclide Imaging. Radionuclide procedures use imaging
techniques and computer analyses to plot and detect the passage
of radioactive tracers through the region of the heart. Such tracing
elements are typically given intravenously. Radionuclide imaging
is useful for the following situations:
- Diagnosing
or determining the severity of unstable angina when less expensive
diagnostic approaches are unavailable or unreliable.
- Determining
the severity of chronic coronary artery disease.
- To assess
the success of surgeries for coronary artery disease.
- To diagnose
a heart attack.
Blood
and Urine Markers
When heart cells
become damaged, they release different enzymes and other molecules
into the blood stream. Elevated levels of such markers
of heart damage in the blood or urine may help predict a heart attack
in patients with severe chest pain. Some of these factors include
the following:
- Troponins.
The proteins cardiac troponin T and I are released when the
heart muscle is damaged. Both are proving to be among the best
diagnostic indications of heart attacks.
- Creatine
kinase myocardial band (CK-MB). CK-MB has been a standard marker
but the MB fraction is not very accurate, since elevated levels
can appear in people without heart injury. Certain forms of
CK-MB, however, may improve its ability to specifically target
heart injury.
- Myoglobin.
Myoglobin is a protein found in heart muscles. It is released
early in the injured heart and it may be useful in combination
with CK-MB and the troponins.
- Fibrinogen.
Fibrinogen is a protein involved in blood clotting, but it is
not routinely measured at this time.
- Brain
(B-type) natriuretic peptide. This is a hormone that is synthesized
in the heart. High levels may identify patients at higher risk
for a poor outcome from heart attack or acute coronary syndromes.
- C-Reactive
Protein. C-reactive protein is a product of the inflammatory
process. Elevated levels may be important indicators for aggressive
treatment in patients with unstable angina. At this time, it
is not routinely measured.
Ruling
out Other Causes of Symptoms
Other Conditions
that Cause Chest Pain. Many conditions may cause chest pain.
High on the list are the following:
- Rupture
of the aorta, collapsed lung, acute inflammation of the heart,
or a blood clot in the lung.
- Anxiety
attacks.
- Gastrointestinal
disorders (gallstone attacks, peptic ulcer disease, hiatal hernia,
heartburn).
- Asthma.
- Problems
affecting the ribs and chest muscles (injured muscles, fractures,
arthritis, spasms, infections).
- Spasm
in the coronary artery.
- Abnormalities
of the heart muscle itself.
- Hyperthyroidism.
- Anemia.
- Vasculitis
(a group of disorders that cause inflammation of the blood vessels).
- Exposure
to high altitudes (rare).
Determining
Treatments and Severity
Patients with
chest pain and ECG showing elevated ST segments or other obvious
signs of dangerous blockage usually have heart attacks and are immediately
treated accordingly. Patients with chest pain and ECGs showing non-elevated
ST-segments, however, may have angina, unstable angina, or pending
heart attack. [ See Electrocardiogram above.] Unstable
angina and non-Q-wave myocardial infarction are collectively referred
to as acute coronary syndromes.
In order to predict which patients with non-elevated ST segments
are most at risk for developing a more serious condition with two
weeks of admission, some experts developed a very promising and
easy scoring system based on the following criteria:
- Age 65
years or older.
- Three
or more risk factors for heart disease (family history, hypertension,
diabetes, current smoking, or unhealthy cholesterol levels).
- Previous
blockage of an artery of at least 50%.
- ST-segment
deviation.
- Severe
angina symptoms.
- Aspirin
use within the previous week.
- Elevated
creatine kinase or its MB fraction. [ See Blood and Urine
Tests above.]
In one 2000 study,
the lowest score (having 1 or none of these risk factors) suggested
a 5% risk for a so-called triple endpoint: death from any cause,
nonfatal heart attack, and arteries that are so blocked that they
require an urgent operation to open them within two weeks. The highest
score (6 or 7) suggested a 40% risk.
WHAT
ARE THE GENERAL PROCEDURES IN THE EMERGENCY ROOM AND GUIDELINES
FOR TREATING A HEART ATTACK?
Diagnosing
a Heart Attack and Determining Treatment Options
Patients with
heart disease or those with risk factors should seek emergency medical
help if they have any signs or symptoms of an attack. Early treatment
is critical for recovery. (A 2000 study has warned that patients
at highest risk for late arrivals are those who are poor, female,
and African American.)
When a patient arrives at the hospital with a possible heart attack
the patient is given an electrocardiogram within 10 minutes and
put on constant monitoring. Blood and other tests are taken to determine
the condition. [ See What Are the Tests used to Determine
a Heart Attack?]
Treatment options will depend on whether the patient has angina,
acute coronary syndromes, or a full-blown heart attack. [For information
on acute coronary syndromes, see Box Guidelines
for Managing Acute Coronary Syndromes.]
Oxygen
Oxygen is almost
always administered right away, usually through a tube that enters
through the nose. The patient is given aspirin if one was not taken
at home.
Drugs
Used to Relieve Pain and Produce Comfort
Nitroglycerin.
Most heart attack patients will usually receive nitroglycerin, usually
under the tongue. Nitroglycerin decreases blood pressure and dilates
the blood vessels around the heart, increasing blood flow. Nitroglycerin
may be given intravenously in certain cases (eg, those with recurrent
angina, congestive heart failure, or high blood pressure). There
is some evidence suggesting that intravenous administration may
help reduce long-term heart muscle changes that can occur after
a heart attack. (Patients with very low blood pressure or severely
slow heart rate will not receive nitroglycerin.)
Morphine. Morphine not only relieves pain and reduces anxiety
but it also dilates blood vessels, thereby aiding the circulation
of blood and oxygen to the heart. Morphine can decrease blood pressure
and slow down the heart. In certain patients where such conditions
can worsen their heart attacks, other drugs such as meperidine (Demerol)
or nalbuphine (Nubain) may be used.
Atropine. Atropine may be given for a very low heart rate
(bradycardia) or signs of atrioventricular (AV) block, in which
electric conduction of nerve impulses to specialized muscles in
the heart is slowed or interrupted.
Antianxiety Agents. Select patients may be given medications
to reduce anxiety, such as haloperidol, although they are not routinely
administered unless the patients are agitated or delirious.
Opening
the Arteries: Clot Busting Drugs Versus Surgery
After a heart
attack, clots form in the injured artery within four to six hours
in 90% of heart attack victims. Opening a clotted artery as quickly
as possible is the best approach to improving survival. (One study
reported that very early treatment may even help reduce the long-term
risk for heart failure.)
Specific medical and surgical solutions to this problem are now
available. Primarily, they involve the following.
- Thrombolytics
are known as blood-clot-busting drugs. They are now the standard
medications used to open the arteries. [ See What Are
Thrombolytic Drugs Used To Restore Blood Flow After a Heart
Attack?]
- Angioplasty
is the major surgical procedure for opening the arteries. [
See What Are the Surgical Procedures for Restoring Blood
Flow After Heart Attack?]
A number of studies
indicated that in centers experienced with emergency angioplasty,
the surgical procedure is more effective than thrombolytic therapy
in many patients, particularly those who have risk factors for bleeding
or stroke. It should be noted, however, that angioplasty has better
results than thrombolytic agents only in centers that have
performed many of these procedures. Nevertheless, as more and more
centers become experienced in angioplasty, it is becoming an increasingly
advantageous option.
Combinations of Thrombolytics and Angioplasty. Some studies
suggest that a combination of early administration of a thrombolytic
followed by angioplasty may prove to have significant benefits for
many patients. Although adverse effects are of concern, one 2001
study reported that after two years, 90% of patients with this combined
approach were alive and had not suffered a recurrent heart attack.
It should be noted not all are candidates for both and that specific
patient groups may do better with one treatment or the other. [Individual
discussions of each approach are covered in detail in other sections.]
Other
Heart Supportive Agents
After a heart
attack, the patient may need a number of different medications,
depending on their risk factors for a future heart attack:
- Anti-clotting
agents are used to prevent further blood clots. They include
anti-platelet drugs (aspirin, glycoprotein IIb/IIIa receptor
antagonists, clopidogrel) or anticoagulants (eg, heparin, warfarin).
They may be used alone or in combinations.
- Beta-blockers
reduce the oxygen demand of the heart by slowing the heart rate
and lowering arterial pressure. Intravenous administration of
beta-blockers (metoprolol or esmolol) within the first few hours
of a heart attack can reduce the destruction of heart tissue.
- Cholesterol
lowering agents. Agents called statins are particularly beneficial
for heart attack patients and may have heart-protective properties
that go beyond lowering cholesterol.
- Angiotensin
converting enzyme (ACE) inhibitors are becoming important after
a heart attack, particularly in patients at risk for heart failure.
[For details,
see What Are Other Agents Used for Heart Attacks and for
Treating Acute Coronary Syndrome?]
Treatment
for Patients in Shock or with Congestive Heart Failure
Severely ill
patients, particularly those in shock (a dangerous condition that
includes a drop in blood pressure and other abnormalities) or with
congestive heart failure, will be monitored closely and stabilized.
Fluids are administered or replaced when it is appropriate to either
increase or reduce blood pressure. In patients with shock, pressure
in the arteries may be measured using a catheter that is inserted
into a major artery. A procedure called intra-aortic balloon counterpulsation
is used to treat shock, which involves coordinating the inflation
and deflation of a balloon within the artery to boost blood pressure.
Treatment
and Prevention of Arrhythmias
An arrhythmia
is a deviation from the heart's normal beating pattern caused when
the heart muscle is deprived of oxygen and is a dangerous side effect
of a heart attack. A very fast or slow rhythmic heart rate often
occurs in heart attack patients and is not usually a dangerous sign.
Premature beats or very fast arrhythmias called tachycardia, however,
may be predictors of ventricular fibrillation . This
is a lethal rhythm abnormality, in which the ventricles of the heart
beat so rapidly that they do not actually contract but quiver ineffectually.
The pumping action necessary to keep blood circulating is lost.
Preventing Arrythmias. People who develop ventricular fibrillation
do not always experience warning arrhythmias, and to date, there
are no effective agents for preventing arrhythmias.
- Potassium
and magnesium levels should be monitored and maintained.
- Intravenous
beta-blockers followed by oral administration of the drugs may
help prevent arrhythmias in certain patients.
- Implantable
cardioverter-defibrillators are being investigated for select
groups of high-risk patients. These are devices that administer
electrical shocks that are timed to counteract the abnormal
rhythms.
Treating Arrhythmias.
- Patients
who develop ventricular arrhythmias are given electrical shocks
with defibrillators to restore normal rhythms.
- Antiarrhythmic
Agents. Antiarrhythmic drugs include lidocaine, procainamide,
or amiodarone. People with an arrhythmia called atrial fibrillation
have a higher risk for stroke after a heart attack and should
be treated very aggressively. Other rhythm disturbances called
bradyarrythmias (very slow rhythm disturbances) frequently develop
in association with a heart attack and may be treated with atropine
or pacemakers.
|
GUIDELINES FOR MANAGING ACUTE CORONARY SYNDROMES
An acute
coronary syndrome is either unstable angina or a non-Q wave
heart attack, they are less severe than heart attacks but
may develop into full-blown attacks without aggressive treatment.
The generally recommended initial approach is as follows:
Perform Diagnostic Tests. Using the results of electrocardiograms
and blood tests, including those for the protein troponin
T, the physician determines which patients need the most aggressive
treatments.
Administer Medications. Appropriate anti-clotting medications
are started immediately in all patients.
-
Aspirin is given to low-risk patients.
-
Heparin is generally used in moderate to high-risk patients.
Low-molecular weight heparin, such as enoxaparin, may
prove to be more effective in reducing mortality rates
than standard heparin.
-
Specific anti-clotting agents called glycoprotein IIb/IIIa
inhibitors are also now being used alone or with heparin
in higher-risk patients.
Other medications
may be appropriate depending on coinciding conditions. For
example, studies are suggesting that aggressive use of statins
(important cholesterol-lowering agents) can reduce the risk
for a heart event in patients with high cholesterol levels
and acute coronary syndromes. Whether they have the same impact
on patients with normal cholesterol levels is less clear.
Determine More Aggressive Therapies. The best candidates
for aggressive procedures appear to be those who are at high-
or intermediate risk for a heart attack and who have blood
tests that show elevated levels of the protein troponin T.
In general, a combination of surgery and anti-clotting medications
may be the best approach for such patients. For example, specific
glycoprotein IIb/IIIa inhibitors, such as abciximab, are proving
to be very effective when used along with angioplasty and
coronary stenting, especially for high-risk patients. [ See
Also Box Anti-Clotting
Agents.] |
WHAT
ARE THROMBOLYTIC DRUGS USED TO RESTORE BLOOD FLOW AFTER A HEART
ATTACK?
Thrombolytic,
or clot-busting, drugs are now a mainstay in the early treatment
of heart attacks. These drugs dissolve the clot, or thrombus, responsible
for causing artery blockage and heart-muscle tissue death.
Specific
Thrombolytics
The current standard
thrombolytic drug is t-PA or alteplase (Activase). Others used include
reteplase (Retavase), urokinase (Abbokinase), and finally streptokinase
(Kabikinase, Streptase). Reteplase and alteplase are equally effective,
and the other two are somewhat less effective. Tenectaplase, a newer
agent can be delivered more rapidly than alteplase, and to date,
survival rates are similar. Others include lanoteplase and anistreplase
(Eminase).
Thrombolytic
Administration
The earlier thrombolytic
drugs are administered, the better. The advantages of thrombolytics
are highest in the first 90 minutes and are still considerable at
three hours. In fact, administering thrombolytics in the ambulance
may reduce the risk for death by over 15%. (Not all chest pain victims
have heart attacks, however, and not all heart attack patients are
candidates for thrombolytics. Such administration should be done
only by an experienced health professional.) Administering these
drugs more than 6 hours after symptoms have started adds little
or no benefit.
A thrombolytic agent, such as alteplase or tenecteplase, is typically
administered with intravenous heparin, an anticoagulant agent. Enoproxin,
a form of heparin called low-molecular weight heparin, may be more
beneficial than standard heparin. (Heparin, like aspirin, cannot
destroy existing blood clots but can prevent clots from reforming
after they are broken up.)
Other anti-clotting agents are being tested in combination with
thrombolytic agents. Of particular interest are studies on combinations
of thrombolytics with the glycoprotein IIb/IIIa receptor antagonists.
Results to date, however, are mixed, and it is not clear which patients
might benefit from this approach.
Complications
Hemorrhagic stroke,
usually occuring during the first day, is the most serious complication
of thrombolytic therapy, but fortunately it is rare. Streptokinase
given without heparin poses the lowest risk (although it is also
less effective than other regimens in restoring blood flow). In
general, the mortality rate from bleeding is only three in every
1,000 patients treated with thrombolytics, whereas 39 patients out
of 1,000 would die without these clot-busting drugs. Recent evidence
suggests that the survival benefits of thrombolytic therapy, particularly
in combination with aspirin, last for years.
Candidates
The best candidates
for thrombolytic therapy are the following:
- Adults
younger than 75 years old with elevated ST segments or indications
of bundle branch block (an ECG reading showing an interruption
in the electrical pathway within the heart). Symptoms occurred
within 12 hours. The benefits extend to people fitting this
description who have diabetes, systolic blood pressure less
than 180 mm Hg, any heart rate, or a history of heart attack.
The use of thrombolytics
in the following patients should be avoided or used with great caution:
- People
older than 75. A 2000 study suggested that their risk of death
was 38% higher than patients in their age group who were not
given therapy. A higher risk exists in such older patients even
if they are otherwise healthy.
- Patients
with elevated ST segments whose symptoms have continued beyond
12 hours.
- Patients
with nonelevated ST-segment heart attacks. (More studies are
needed to confirm this, however.)
- Pregnant
women.
- People
who have experienced recent trauma (especially head injury)
or invasive surgery.
- People
with active peptic ulcers.
- Patients
who have been given prolonged CPR.
- Current
users of anticoagulants
Thrombolytics
should not be used in the following patients:
- Patients
who have experienced any recent major bleeding.
- Patients
with depressed ST segments.
- Patients
with a history of stroke. (Selected patients whose strokes were
not recent may benefit from these drugs, but more research is
needed to confirm this.)
- Patients
with uncontrolled high blood pressure.
A number of studies
report that women do worse after thrombolytic therapy. Evidence
indicates, however, that they are generally older with more serious
medical conditions when they seek treatment. One study also reported
that women were given these drugs an average of 14 minutes later
than men were. Women on thrombolytic therapy still do better than
those not given these drugs. The bottom line is that thrombolytic
therapy is life saving, and appropriate candidates, regardless of
age or gender, should not be denied this therapy.
WHAT
ARE THE SURGICAL PROCEDURES FOR RESTORING BLOOD FLOW AFTER A HEART
ATTACK?
Revascularization
Procedures for Opening Blocked Arteries
Percutaneous
transluminal coronary angioplasty and coronary artery bypass graft
surgery, known as revascularization procedures,
are the standard operations for opening narrowed or blocked arteries.
Emergency angioplasty is the more common procedure for heart attack
patients. Coronary bypass surgery is used if angioplasty or thrombolytics
fail or are not appropriate. It is usually not performed for a few
days to allow recovery of the heart muscles. In a 2000 Swedish study,
heart-attack patients who underwent either angioplasty or bypass
surgery within fourteen days of being admitted to the hospital reduced
their one-year risk of death by more than 40%.
Candidates
for Emergency Angioplasty
As with thrombolytic
treatments, angioplasty is most effective when performed within
12 hours of symptoms, and the sooner the better. The best candidates
are the following:
- Most patients
who are also good candidates for thrombolytic therapy.
- Women
who meet the criteria for both approaches may be better candidates
for angioplasty than thrombolytic therapy.
- Elderly
patients who meet the criteria for both approaches may be better
candidates for angioplasty than thrombolytic therapy.
- Patients
with diabetes who meet the criteria for both approaches.
- Patients
under age 75 who go into shock and when angioplasty can be performed
within 18 hours of shock. (There is no advantage for patients
over 75 who are in shock.)
- Although
revascularization is not effective in most patients with non-ST
elevation heart attacks, it might benefit certain subsets of
these patients, such as those who show reduced blood flow in
the damaged artery and when angioplasty can be performed within
12 hours.
- Two 1999
studies have suggested that angioplasty may be better for older
people than thrombolytic therapy. In one five-year study, mortality
rates after angioplasty were 13% compared to 24% with thrombolytics.
Not all hospitals are equipped for emergency angioplasty, however.
In such cases, thrombolysis is still a good option, and other
treatments are being investigated.
It should be
strongly noted that the experience of the medical center's staff
is critical for optimal benefits, and not all surgeons are experienced
in angioplasty. However, the procedure is becoming increasingly
available and overall mortality rates are improving over time with
angioplasty. Patients or their families should be sure their surgeon
has performed at least 75 of these procedures and that the medical
center has performed at least 200.
Angioplasty
and Coronary Stents
Percutaneous
transluminal coronary angioplasty (PTCA), usually simply called
angioplasty, involves opening the blocked artery. A typical angioplasty
procedure follows the following steps:
- The surgeon
threads a narrow catheter (a tube) containing a fiber optic
camera directly to the blocked vessel.
- The physician
opens the blocked vessel using balloon angioplasty ,
in which the surgeon passes a tiny deflated balloon through
the catheter to the vessel.
- The balloon
is inflated to compress the plaque against the walls of the
artery, flattening it out so that blood can once again flow
through the blood vessel freely.
- In order
to keep the artery open afterwards, surgeons now often employ
a device called a coronary stent, which is an
expandable metal mesh tube that is implanted during angioplasty
at the site of the blockage. Once in place, the stent pushes
against the wall of the artery to keep it open. There has been
some concern that a metal stent might increase the risk for
blood clot formations, but the use of anti-clotting medications
and improvements in the stent have improved restenosis (reclosure)
rates compared to angioplasty alone. (Stenting is also now being
investigated as a primary treatment with good results in certain
patients.)
- Complications
occur in about 10% of patients (about 80% within the first day).
Serious ones include heart attack and the need for additional
surgery. Outcomes are better in hospital settings with experienced
teams and backup.
Studies report
high survival rates with the use of stents, including their use
with multiple blood vessels. Most, but not all, patients are suitable
candidates for stents.
Reclosure and Blockage During or Shortly after Angioplasty and
Prevention. Reclosure of the artery during or shortly after
angioplasty often occurs. A number of anti-clotting agents are used
to help prevent this, although they are not wholly protective because
reclosure in some cases is due to other, unknown causes.
Prevention of Restenosis. Narrowing or reclosing of the artery
(restenosis) occurs within a year of angioplasty in a large minority
of angioplasty patients, often requiring a repeat operation. The
narrowing of the artery in this case is not due to blood clots and
so anti-clotting agents are not useful. A number of approaches have
been developed to prevent restenosis after angioplasty. Most are
still investigative. [For more information, see Report
#3 Coronary Artery Disease and Angina.]
Other
Procedures
In certain cases,
other surgical procedures may be required to repair injuries to
the heart or blood vessel.
WHAT
ARE OTHER AGENTS USED FOR HEART ATTACKS AND FOR TREATING ACUTE
CORONARY SYNDROMES?
In addition to
thrombolytics, a number of agents are now available for use during
a heart attack and for treating acute coronary syndrome. Some of
these and other medications are also important for preventing either
a first or a second heart attack.
Aspirin
and Other Anti-Clotting Agents
Blood clots are
a major factor in heart attacks. Anti-clotting agents that inhibit
or break up blood clots are used at every stage of heart disease.
They are generally either anti-platelet agents or anticoagulants.
Investigators are also studying combinations of anti-clotting agents,
which may be useful in patients with severe heart disease. All anti-clotting
therapies carry the risk of bleeding, which can lead to dangerous
situations, including stroke. [ See Table Anti-Clotting
Agents.]
Anti-Platelet Agents . Anti-platelet agents prevent formation
of blood platelets. Platelets are very small disc-shaped blood cells
that are important for blood-clotting.
- Aspirin.
Aspirin is an antiplatelet agent. It is the most common
anti-clotting drug and nearly anyone with heart disease is advised
to take it daily in low dose. Aspirin alone has been reported
to reduce risk of death from heart attack or stroke by 25% to
50% and to cut risk of non-fatal heart attacks by 34%.
- Glycoprotein
IIb/IIIa Inhibitors. These potent blood-thinning agents
include abciximab (ReoPro, Centocor), eptifibatide (Integrilin),
tirofiban (Aggrastat), and lamifiban. They are administered
intravenously in the hospital and are being used after surgery
angioplasty and stent placement. [ See Angioplasty and
Coronary Stents , below. ] Other benefits are not yet
clear.
- Thienopyrindines.
Clopidogrel (Plavix) and ticlopidine (Ticlid) are potent
oral platelet inhibitors.
Anticoagulants.
Anticoagulants help thin blood and include the following:
- Heparin.
Standard and low-molecular weight heparin (enoxaparin, dalteparin,
tinzaparin).
- Warfarin
(Coumadin).
How Anti-Clotting
Agents are Used. Such agents may be used immediately after a
heart attack and also as on-going maintenance to prevent a heart
attack in patients with acute coronary syndromes (unstable angina
and non-ST elevation heart attacks).
The following anti-clotting agents are used during a heart attack:
- The physician
usually gives the patient heparin or aspirin, either alone or
in combination with thrombolytic therapy. Unlike the thrombolytic
(clot-busting ) agents, anti-clotting agents do not dissolve
clots that have already formed, but they do help prevent new
ones from forming. Aspirin should be given immediately, and
heparin is usually started during or at the end of the thrombolytic
infusion.
- Other
agents, such as glycoprotein IIb/IIIa receptor antagonists,
are being tested in combination with thrombolytic agents.
All these drugs
pose a risk for hemorrhage.
Beta-Blockers
Beta-blockers
reduce the oxygen demand of the heart by slowing the heart rate
and lowering pressure in the arteries. They are now well known for
reducing deaths from heart disease. They include propranolol (Inderal),
carvedilol (Coreg), bisoprolol (Zebeta), acebutolol (Sectral), atenolol
(Tenormin), labetalol (Normodyne, Trandate), metoprolol (Lopressor.
Toprol-XL), and esmolol (Brevibloc).
Administration during a Heart Attack. Intravenous administration
of beta-blockers (metoprolol or esmolol) within the first few hours
of a heart attack can reduce the destruction of heart tissue. Evidence
strongly supports a lower incidence of complications and better
survival rates after a heart attack in patients who had been treated
with a beta-blocker.
Prevention after a Heart Attack. Beta-blockers are also
important after a heart attack in preventing another heart attack.
In fact, among elderly heart attack patients, those who do not use
these agents afterward have a much poorer outcome.
Side Effects. Side effect include the following:
- Some beta-blockers
lower HDL cholesterol (the beneficial cholesterol) by about
10%. The effect is most marked in smokers.
- Fatigue
and lethargy are the most common neurologic side effects. Some
people experience vivid dreams and nightmares, depression, and
memory loss.
- Exercise
capacity may be reduced.
- Other
side effects may include cold extremities, asthma, decreased
heart function, gastrointestinal problems (eg, heartburn, gas,
diarrhea, or constipation), and sexual dysfunction.
- Dizziness
and lightheadedness, especially when getting up from a lying
down position.
If side effects
occur, the patient should call a physician, but it is extremely
important not to stop the drug abruptly. Angina, heart attack, and
even sudden death have occurred in patients who discontinued treatment
without gradual withdrawal.
Statins
and Other Cholesterol and Lipid-Lower Agents
A number of agents
are available for lowering cholesterol and other dangerous fat molecules
(lipids). They include the following:
- Statins,
resins, and the drug probucol target LDL cholesterol. Statins
and are now the first choice for most people who require lipid-lowering
therapy.
- Fibrates
and niacin (also known as vitamin B3 and nicotinic acid) reduce
triglycerides and increase HDL. (In one report, for example,
the use of niacin plus a statin stopped progression of coronary
artery disease completely.)
In spite of the
obvious benefits of many of these agents, according to one study,
only 37% of patients with recent heart attacks and high cholesterol
levels were given any drugs to lower cholesterol. [For information
on other cholesterol-lowering agents see the Report,
Cholesterol, Other Lipids, and Lipoproteins .]
Statin Drugs. Statins may have significant benefits for heart
patients. Statins are proving to reduce the risk for heart attacks
even in some people with normal or below-normal cholesterol. Researchers
are studying these agents early in the course of a heart attack
to determine if they may improve survival, particularly in high-risk
patients. Of particular importance was a 2001 study that reported
significantly better survival rates in heart attack patients who
took statins at or before discharge from the hospital compared to
those who did not take them. These better survival rates occurred
regardless of any other risk factors. Studies in 2000 and 2001 suggest
that patients with normal cholesterol but signs of inflammation
in the arteries (as indicated by blood tests showing high levels
of C-reactive protein) may specifically benefit from statins.
The statins include two groups:
- So-called
natural statins, including lovastatin (Mevacor), pravastatin
(Pravachol), and simvastatin (Zocor).
- Newer
statins are fluvastatin (Lescol), atorvastatin (Lipitor), and
rosuvastatin (Crestor). The newer agents may reduce LDL more
effectively at equal doses to the natural statins.
Adverse Effects.
Side effects include gastrointestinal discomfort, headaches,
skin rashes, sexual dysfunction, drowsiness, dizziness, nausea,
constipation, and peripheral neuropathy (numbness or tingling in
the hands and feet). Statins can affect the liver, so periodic liver
function tests should be administered. Statins should never be taken
by anyone with liver problems or by women during pregnancy or breast-feeding.
[See also Note on Withdrawal of Cerivastatin (Baycor).]
|
Withdrawal of Cerivastatin (Baycol)
One statin,
Baycol, was withdrawn from the market because of reports of
death from rhabdomyolysis, severe muscle damage that can lead
to kidney failure. People at highest risk were those who were
taking high doses and who also took gemfibrozil. Rhabdomyolysis
has occurred rarely with other statins but has never before
been associated with deaths. |
Combinations
and Interactions with Other Drugs and Substances. Statins
can be used in combinations with other cholesterol lowering agents,
including bile acid-binding resins, nicotinic acid, and fibrates,
for a more wide-spread effect on other lipids. Use with certain
other drugs, however, including nicotinic acid and fibrate, may
increase the risk for muscle weakness or pain. (Other drugs that
may have the same effect are cyclosporin, macrolide antibiotics,
or certain antifungals.) Grapefruit juice may increase their potency.
Angiotensin Converting Enzyme Inhibitors
Angiotensin converting enzyme (ACE) inhibitors are important agents.
In treating heart attack patients, there are commonly administered
soon after an attack, particularly in patients at risk for heart
failure. ACE inhibitors are important agents in hypertension and
are recommended as first-line treatment for people with diabetes
and kidney damage, for some heart attack survivors, and for patients
with heart failure. A 2001 study, in fact, suggested that taking
an ACE inhibitor at the onset of a heart attack may reduce the
damage.
Side Effects. Side effects of ACE inhibitors are uncommon
but may include an irritating cough, excessive drops in blood
pressure, and allergic reactions. Of great concern is research
suggesting that aspirin (and other so-called NSAIDs) increases
the risk for heart failure in patients taking ACE inhibitors.
[See Anti-Clotting Agents below.]
Magnesium
Magnesium has
blood-thinning properties and may help open blood vessels. It is
important to correct any magnesium deficiencies in heart attack
patients (such as those who were on diuretics). For certain patients
who cannot be given thrombolytic therapy, intravenous magnesium
may be helpful. It must be administered within six hours for it
to have any effect. A study that started in 1999 is investigating
whether magnesium is beneficial when used before thrombolytic therapy
or angioplasty.
Infection-Fighting
Agents
Antibiotics.
The antibiotics prescribed for Chlamydia pneumoniae are
being investigated for prevention of heart attacks in patients with
heart disease and evidence of infection. A two-year 2000 study found
no significant effect for these treatments. A 2001 study on heart
attack patients, however, reported that antibiotics were associated
with a lower risk for a second heart attack.
Flu Vaccines. Also interesting was a study reporting that
influenza vaccinations might protect heart attack patients against
another attack during flu season.
WHAT
IS REHABILITATION AFTER A HEART ATTACK?
Physical
Rehabilitation
Physical rehabilitation
is extremely important after a heart attack. It has been associated
with a 25% reduction in mortality rates at three years. Rehabilitation
may involve the following:
- Leg exercises
may start as early as the first day. The patient usually sits
in a chair on the second day, and begins to walk on the second
or third day.
- Most patients
undergo low-level exercise tolerance tests early in their recovery.
One study suggests that exercise testing within three days after
a relatively minor attack may allow patients to go home earlier.
- After
eight to 12 weeks, many patients, even those with heart failure,
benefit from supervised exercise programs. Health professionals
should provide the patient with schedules for low-level aerobic
home-activity. Strength (resistance) training is also important.
(Tai Chi, a Chinese martial art, appears to be very beneficial
and safe for people after a heart attack.) It should be noted
that the risk for serious heart events during rehabilitation
is very low, in one survey cardiac arrest was 1 per 112,000
patient-hours and nonfatal heart attack rates were 1 per 294,000
patient-hours.
- Patients
generally return to work in about two months, although timing
can vary depending on the severity of the condition.
Lifestyle measures,
particularly dietary factors, are equally important in preventing
heart attacks and must be strenuously adhered to. [ See How
Can a Heart Attack be Prevented?, above.]
Emotional
Rehabilitation
Many studies
are showing that depression is a major predictor for increased mortality
in both women and men. Depressed patients are less likely to comply
with their heart medications. Physical rehabilitation itself has
significant and positive emotional effects, that, according to a
2001 study, are important for long-term survival. Antidepressants,
psychologic therapy, or both, are strongly recommended if a patient
becomes severely depressed after a heart attack. There is some evidence
to suggest that the use of antidepressants, which increase serotonin,
may help protect the hearts of people who have both heart disease
and depression.
Sexual activity right after a heart attack carries a very low risk
and is believed to be safe, particularly in people who had exercised
regularly before the attack. In any case, the feelings of intimacy
and love that accompany healthy sex can help offset depression,
a far greater risk for a future attack.
WHERE
ELSE CAN INFORMATION ABOUT HEART ATTACKS BE OBTAINED?
National Heart,
Lung, and Blood Institute, Information Center, P.O. Box 30105, Bethesda,
MD 20824-0105. Call (301-592-8573) or on the Internet (http://www.nhlbi.nih.gov/nhlbi/nhlbi.htm)
Associated with the National Institute of Health, this organization
offers excellent free printed information.
American College of Cardiology, Heart House, 9111 Old Georgetown
Rd., Bethesda, MD 20814-1699. Call (800-253-4636) or (301-897-5400)
or on the Internet (http://www.acc.org/)
American Heart Association, National Center, 7272 Greenville Ave.,
Dallas, Texas 75231-4596. Call (1-800-AHA-USA1) or on the Internet
(http://www.americanheart.org/)
This is a primary source of information for heart problems. They
are very responsible and will send free pamphlets and reading material,
including useful diet information and locations of local representatives.
Medic Alert, 2323 Colorado Ave., Turlock, CA 95382. Call (888-633-4298)
or on the Internet (http://www.medicalert.org).
This organization provides bracelets or neck chain emblems with
critical personal medical information. Also keeps computerized medical
records
Offers a useful heart risk evaluation test. (http://www.heartriskevaluations.com/)
Professional website for news on treating heart attack (http://www.thrombosisconnect.com/)
American Heart Association Guidelines (http://www.americanheart.org/Scientific/statements/)
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