| National Institutes of Health |
National Heart, Lung, and Blood Institute
Heart Failure
Table of Contents
What
is heart failure?
Is
there only one type of heart failure?
How
common is heart failure?
What
causes heart failure?
What
are the symptoms?
How
do doctors diagnose heart failure?
What
treatments are available?
Common
heart failure medications
Can a
person live with heart failure?
What
is the outlook for heart failure?
Making
the most of your doctor visit
A
question for your pharmacist
Glossary
Heart
failure occurs when the heart loses its ability to pump enough blood through
the body. Usually, the loss in pumping action is a symptom of an underlying
heart problem, such as coronary artery disease.
The term heart failure suggests a sudden and complete stop of heart activity.
But, actually, the heart does not suddenly stop. Rather, heart
failure usually develops slowly, often over years, as the heart gradually
loses its pumping ability and works less efficiently. Some people may not become
aware of their condition until symptoms appear years after their heart began its
decline.
How serious the condition is depends on how much pumping capacity the heart
has lost. Nearly everyone loses some pumping capacity as he or she ages. But the
loss is significantly more in heart failure and often results from a heart
attack or other disease that damages the heart.
The severity of the condition determines the impact it has on a person's
life. At one end of the spectrum, the mild form of heart failure may have little
effect on a person's life; at the other end, severe heart failure can interfere
with even simple activities and prove fatal. Between those extremes, treatment
often helps people lead full lives.
But all forms of heart failure, even the mildest, are a serious health
problem, which must be treated. To improve their chance of living longer,
patients must take care of themselves, see their physician regularly, and
closely follow treatments.
The term
congestive
heart failure is often used to describe all patients with heart failure. In
reality, congestion (the buildup of fluid) is just one feature of the condition
and does not occur in all patients. There are two main categories of heart
failure although within each category, symptoms and effects may differ from
patient to patient. The two categories are:
- Systolic
heart failure--This occurs when the heart's ability to contract decreases.
The heart cannot pump with enough force to push a sufficient amount of blood
into the circulation. Blood coming into the heart from the lungs may back up
and cause fluid to leak into the lungs, a condition known as pulmonary
congestion.
- Diastolic
heart failure--This occurs when the heart has a problem relaxing. The
heart cannot properly fill with blood because the muscle has become stiff,
losing its ability to relax. This form may lead to fluid accumulation,
especially in the feet, ankles, and legs. Some patients may have lung
congestion.
Between 2 to 3 million
Americans have heart failure, and 400,000 new cases are diagnosed each year. The
condition is slightly more common among men than women and is twice as common
among African Americans as whites.
Heart failure causes 39,000 deaths a year and is a contributing factor in
another 225,000 deaths. The death rate attributed to heart failure rose by 64
percent from 1970 to 1990, while the death rate from coronary heart disease
dropped by 49 percent during the same period. Heart failure mortality is about
twice as high for African Americans as whites for all age groups.
In a sense, heart failure's growing presence as a health problem reflects the
Nation's changing population: More people are living longer. People age 65 and
older represent the fastest growing segment of the population, and the risk of
heart failure increases with age. The condition affects 1 percent of people age
50, but about 5 percent of people age 75.
As stated, the heart loses
some of its blood-pumping ability as a natural consequence of aging. However, a
number of other factors can lead to a potentially life-threatening loss of
pumping activity.
As a symptom of underlying heart disease, heart failure is closely associated
with the major risk factors for coronary heart disease: smoking, high
cholesterol levels, hypertension (persistent high blood pressure), diabetes and
abnormal blood sugar levels, and obesity. A person can change or eliminate those
risk factors and thus lower their risk of developing or aggravating their heart
disease and heart failure.
Among prominent risk factors, hypertension (high blood pressure) and diabetes
are particularly important. Uncontrolled high blood pressure increases the risk
of heart failure by 200 percent, compared with those who do not have
hypertension. Moreover, the degree of risk appears directly related to the
severity of the high blood pressure.
Persons with diabetes have about a two- to eightfold greater risk of heart
failure than those without diabetes. Women with diabetes have a greater risk of
heart failure than men with diabetes. Part of the risk comes from diabetes'
association with other heart failure risk factors, such as high blood pressure,
obesity, and high cholesterol levels. However, the disease process in diabetes
also damages the heart muscle.
The presence of coronary disease is among the greatest risks for heart
failure. Muscle damage and scarring caused by a heart attack greatly increase
the risk of heart failure. Cardiac arrhythmias,
or irregular heartbeats, also raise heart failure risk. Any disorder that causes
abnormal swelling or thickening of the heart sets the stage for heart failure.
In some people, heart failure arises from problems with heart valves,
the flap-like structures that help regulate blood flow through the heart.
Infections in the heart are another source of increased risk for heart failure.
A single risk factor may be sufficient to cause heart failure, but a
combination of factors dramatically increases the risk. Advanced age adds to the
potential impact of any heart failure risk.
Finally, genetic abnormalities contribute to the risk for certain types of
heart disease, which in turn may lead to heart failure. However, in most
instances, a specific genetic link to heart failure has not been identified.
A number of symptoms are
associated with heart failure, but none is specific for the condition. Perhaps
the best known symptom is shortness of breath
("dyspnea"). In heart failure, this may result from excess fluid in the
lungs. The breathing difficulties may occur at rest or during exercise. In some
cases, congestion may be severe enough to prevent or interrupt sleep.
Fatigue or easy tiring is another common symptom. As the heart's pumping
capacity decreases, muscles and other tissues receive less oxygen and nutrition,
which are carried in the blood. Without proper "fuel," the body cannot perform
as much work, which translates into fatigue.
Fluid accumulation, or edema, may cause swelling of the feet, ankles, legs,
and occasionally, the abdomen. Excess fluid retained by the body may result in
weight gain, which sometimes occurs fairly quickly.
Persistent coughing is another common sign, especially coughing that
regularly produces mucus or pink, blood-tinged sputum. Some people develop raspy
breathing or wheezing.
Because heart failure usually develops slowly, the symptoms may not appear
until the condition has progressed over years. The heart hides the underlying
problem by making adjustments that delay--but do not prevent--the eventual loss
in pumping capacity. The heart adjusts, or compensates, in three ways to cope
with and hide the effects of heart failure:
- Enlargement ("dilatation"), which allows more blood into the heart;
- Thickening of muscle fibers ("hypertrophy") to strengthen the heart
muscle, which allows the heart to contract more forcefully and pump more
blood; and
- More frequent contraction, which increases circulation.
By making
these adjustments, or compensating, the heart can temporarily make up for losses
in pumping ability, sometimes for years. However, compensation has its limits.
Eventually, the heart cannot offset the lost ability to pump blood, and the
signs of heart failure appear.
In many
cases, physicians diagnose
heart
failure during a physical examination. Readily identifiable signs are
shortness of breath, fatigue, and swollen ankles and feet. The physician also
will check for the presence of risk factors, such as hypertension, obesity, and
a history of heart problems. Using a stethoscope, the physician can listen to a
patient breathe and identify the sounds of lung congestion. The stethoscope also
picks up the abnormal heart sounds indicative of heart failure.
If neither the symptoms nor the patient's history point to a clear-cut
diagnosis, the physician may recommend any of a variety of laboratory tests,
including, initially, an electrocardiogram,
which uses recording devices placed on the chest to evaluate the electrical
activity of a patient's heartbeat.
Echocardiography
is another means of evaluating heart function from outside the body. Sound waves
bounced off the heart are recorded and translated into images. The pictures can
reveal abnormal heart size, shape, and movement. Echocardiography
also can be used to calculate a patient's ejection fraction, a measure of the
amount of blood pumped out when the heart contracts.
Another possible test is the chest x ray, which also determines the heart's
size and shape, as well as the presence of congestion in the lungs.
Tests help rule out other possible causes of symptoms. The symptoms of heart
failure can result when the heart is made to work too hard, instead of from
damaged muscle. Conditions that overload the heart occur rarely and include
severe anemia and thyrotoxicosis (a disease resulting from an overactive thyroid
gland).
Heart failure
caused by an excessive workload is curable by treating the primary disease, such
as anemia or thyrotoxicosis. Also curable are forms caused by anatomical
problems, such as a heart valve defect. These defects can be surgically
corrected.
However, for the common forms of heart failure--those due to damaged heart
muscle--no known cure exists. But treatment for these forms may be quite
successful. The treatment seeks to improve patients' quality of life and length
of survival through lifestyle change and drug therapy.
Patients can minimize the effects of heart failure by controlling the risk
factors for heart disease. Obvious steps include quitting smoking, losing weight
if necessary, abstaining from alcohol, and making dietary changes to reduce the
amount of salt and fat consumed. Regular, modest exercise is also helpful for
many patients, though the amount and intensity should be carefully monitored by
a physician.
But, even with lifestyle changes, most heart failure patients must take
medication. Many patients receive two or more drugs.
Several types of drugs have proven useful in the treatment of heart failure:
- Diuretics help reduce the amount of fluid in the body and are useful for
patients with fluid retention and hypertension.
- Digitalis increases the force of the heart's contractions, helping to
improve circulation.
- Results of recent studies have placed more emphasis on the use of drugs
known as angiotensin
converting enzyme (ACE) inhibitors. Several large studies have indicated
that ACE
inhibitors improve survival among heart failure patients and may slow, or
perhaps even prevent, the loss of heart pumping activity.
Originally
developed as a treatment for hypertension, ACE inhibitors help heart failure
patients by, among other things, decreasing the pressure inside blood vessels.
As a result, the heart does not have to work as hard to pump blood through the
vessels.
Patients who cannot take ACE inhibitors may get a nitrate and/or a drug
called hydralazine, each of which helps relax tension in blood vessels to
improve blood flow.
Sometimes, heart failure is life-threatening. Usually, this happens when drug
therapy and lifestyle changes fail to control its symptoms. In such cases, a
heart transplant may be the only treatment option. However, candidates for
transplantation often have to wait months or even years before a suitable donor
heart is found. Recent studies indicate that some transplant candidates improve
during this waiting period through drug treatment and other therapy, and can be
removed from the transplant list.
Transplant candidates who do not improve sometimes need mechanical pumps,
which are attached to the heart. Called left ventricular assist devices (LVADs),
the machines take over part or virtually all of the heart's blood-pumping
activity. However, current LVADs
are not permanent solutions for heart failure but are considered bridges to
transplantation.
An experimental surgical procedure for severe heart failure is available at a
few U.S. medical centers. The procedure, called cardiomyoplasty,
involves detaching one end of a muscle in the back, wrapping it around the
heart, and then suturing the muscle to the heart. An implanted electric
stimulator causes the back muscle to contract, pumping blood from the heart.
|
Listed
below are some of the medications prescribed for heart failure. Not all
medications are suitable for all patients, and more than one drug may be
needed.
Also, the list provides the full range of possible side effects for
these drugs. Not all patients will develop these side effects. If you
suspect that you are having a side effect, alert your physician.
- ACE Inhibitors.
These prevent
the production of a chemical that causes blood vessels to narrow. As a
result, blood pressure drops and the heart does not have to work as hard
to pump blood.
- Side effects may include coughing, skin rashes, fluid
retention, excess potassium in the bloodstream, kidney problems, and
an altered or lost sense of taste.
- Digitalis.
Increases the force of the heart's
contractions. It also slows certain fast heart rhythms. As a result, the
heart beats less frequently but more effectively, and more blood is
pumped into the arteries.
- Side effects may include nausea, vomiting, loss of
appetite, diarrhea, confusion, and new heartbeat irregularities.
- Diuretics.
These decrease the body's retention
of salt and so of water. Diuretics are commonly prescribed to reduce
high blood pressure. Diuretics come in many types, with different
periods of effectiveness.
- Side effects may include loss of too much potassium,
weakness, muscle cramps, joint pains, and impotence.
- Hydralazine.
This drug widens blood vessels,
easing blood flow.
- Side effects may include headaches, rapid heartbeat, and
joint pain.
- Nitrates.
These drugs are used mostly for chest
pain, but may also help diminish heart failure symptoms. They relax
smooth muscle and widen blood vessels. They act to lower primarily
systolic blood pressure.
- Side effects may include headaches.
|
Heart failure is
one of the most serious symptoms of heart disease. About two-thirds of all
patients die within 5 years of diagnosis. However, some live beyond 5 years,
even into old age. The outlook for an individual patient depends on the
patient's age, severity of heart failure, overall health, and a number of other
factors.
As heart failure progresses, the effects can become quite severe, and
patients often lose the ability to perform even modest physical activity.
Eventually, the heart's reduced pumping capacity may interfere with routine
functions, and patients may become unable to care for themselves. The loss in
functional ability can occur quickly if the heart is further weakened by heart
attacks or the worsening of other conditions that affect heart failure, such as
diabetes and coronary heart disease.
Heart failure patients also have an increased risk of sudden
death, or cardiac arrest, caused by an irregular heartbeat.
To improve the chances of surviving with heart failure, patients must take
care of themselves.
Patients must:
- See their physician regularly;
- Closely follow all of their physician's instructions;
- Take any medication according to instructions; and
- Immediately inform their physician of any significant change in their
condition, such as an intensified shortness of breath or swollen feet.
Patients with heart failure also should:
- Control their weight;
- Watch what they eat;
- Not smoke cigarettes or use other tobacco products; and
- Abstain from or strictly limit alcohol consumption.
Even with the
best care, heart failure can worsen, but patients who don't take care of
themselves are almost writing themselves a prescription for poor health.
The best defense against heart failure is the prevention of heart disease.
Almost all of the major coronary risk factors can be controlled or eliminated:
smoking, high cholesterol, high blood pressure, diabetes, and obesity.
Within the
past decade, knowledge of heart failure has improved dramatically but, clearly,
much more remains to be learned. The National Heart, Lung, and Blood Institute
(NHLBI) supports numerous research projects aimed at building on what is already
known about heart failure and at uncovering new knowledge about its process,
diagnosis, and treatment. NHLBI research priorities for heart failure include:
- Learning more about basic cellular changes that lead to heart failure;
- Developing tests to detect the earliest signs of heart failure;
- Identifying factors that cause heart failure to worsen;
- Determining how heart failure can be reversed once it starts;
- Understanding better the heart's ability to compensate for lost pumping
ability; and
- Developing new therapies, especially those based on early signs of heart
failure.
|
Here are
some points you may want to discuss with your doctor. Don't hesitate to
ask questions to clarify points. Also, ask your doctor to rephrase a reply
you cannot understand. You may want to take a family member or friend to
the appointment with you to help you better understand and remember what's
said.
- Briefly describe your symptoms, even those you feel may not be
important. You may want to keep a list so you will remember them.
- Tell the doctor all of the medications you take--including
over-the-counter drugs--and any problems you may be having with them.
- Be sure you understand all of the doctor's instructions--especially
for medications. Know what drug to take when, how often, and in what
amount.
- Find out what side effects are possible from any drug the doctor
prescribes for you.
- Ask the meaning of any medical term you don't understand.
- If, after your appointment, you still have questions or are
uncertain about your treatment, call the doctor's office to get the
information you need.
A QUESTION FOR YOUR PHARMACIST Your pharmacist is a good
resource for information about medications. Ask if any drug you're taking
interacts badly with certain foods or with other drugs, including
nonprescription ones. Your pharmacist also can help you understand product
package inserts and label instructions.
|
|
|
Glossary
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Public Health
Service
National Institutes of Health
National Heart, Lung, and Blood
Institute
NIH Publication No. 95-923
Reprinted May 1997