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Heart Failure
Heart failure is a progressive disorder in which damage to the
heart causes weakening of the cardiovascular system. It
manifests by fluid congestion or inadequate blood flow to
tissues. Heart failure progresses by underlying heart injury
or inappropriate responses of the body to heart impairment.
Heart failure may result from one or the sum of many causes.
It is a progressive disorder that must be managed in regard to
not only the state of the heart, but the condition of the
circulation, lungs, neuroendocrine system and other organs as
well. Furthermore, when other conditions are present (e.g.
kidney impairment, hypertension, vascular disease, or
diabetes) it can be more of a problem. Finally, the impact it
can have on a patient psychologically and socially are
important as well.Heart failure is a cumulative consequence of
all insults to the heart over someone's life. It is estimated
that nearly 5 million Americans have heart failure. The
prevalence of heart failure approximately DOUBLES with each
decade of life. As people live longer, the occurrence of heart
failure rises, as well as other conditions that complicate its
treatment. Even when symptoms are absent or controlled,
impaired heart function implies a reduced duration of
survival. Fortunately,
many factors that can prevent heart failure and improve
outcome are known and can be applied at any stage.
Heart Failure Symptoms
Fluid Congestion
If the heart becomes less efficient as a pump, the body will
try to compensate for it. One way it attempts to do this is by
using hormones and nerve signals to increase blood volume (by
water retention in the kidneys). A drop in blood flow to the
kidneys will also lead to fluid retention. Blood and fluid
pressure backed up behind the heart result in excess salt
water entering the lungs and other body tissues. However, it
is important to note that not all swelling due to fluid
retention is a reflection of heart failure.Clinical symptoms
due to fluid congestion:
Shortness of breath
Reduced Blood Flow to the Body. The heart's inability to pump
blood to the muscles and organs isn't always apparent in early
stages of heart failure. Often times, it is unmasked only
during increases in physical activity. In advanced heart
failure, many tissues and organs may not even receive the
oxygen they require for functioning at rest. Clinical symptoms
due to poor blood flow to the body: difficulty exercising
fatigue dizziness (due to low blood pressure) Heart Failure
Classifications.
The symptoms and physical changes of heart failure
have several different classifications based on their location
and mechanism.
Right vs. Left Sided Heart Failure
Right Heart Failure - The
inability of the right side of the heart to adequately pump
venous blood into the pulmonary circulation. This causes a
back-up of fluid in the body, resulting in swelling and edema.
Left Heart Failure - The inability of the left side of
the heart to pump into the systemic circulation. Back-up
behind the left ventricle causes accumulation of fluid in the
lungs.
As a result of those failures, symptoms can
be due to:
Forward Heart Failure -
The inability of the heart to pump blood at a sufficient rate
to meet the oxygen demands of the body at rest or at exercise.
Backward Heart Failure - The
ability of the heart to pump blood at a sufficient rate ONLY
when heart filling pressures are abnormally high.
Congestive Heart Failure -
Fluid in the lungs or body, resulting from
inadequate pumping from the heart and high
heart filling and venous pressures.
How quickly does heart failure develop?
Heart failure is usually a chronic disease. That means
it's a long-term condition that tends to gradually become
worse. By the time someone is diagnosed, chances are that the
heart has been losing pumping capacity little by little for
quite a while. At first the heart tries to make up for this
by:
·
Enlarging.
When the heart chamber enlarges, it stretches more and can
contract more strongly, so it pumps more blood.
·
Developing
more muscle mass.
The increase in muscle mass occurs because the contracting
cells of the heart get bigger. This lets the heart pump
more strongly, at least initially.
·
Pumping
faster.
This helps to increase the heart's output.
The body also tries to compensate in other ways. The
blood vessels narrow to keep blood pressure up, trying to make
up for the heart's loss of power. The body diverts blood away
from less important tissues and organs to maintain flow to the
most vital organs, the heart and brain. These temporary
measures mask the problem of heart failure, but they don't
solve it. This helps explain why some people may not become
aware of their condition until years after their heart begins
its decline. (It's also a good reason to have a regular
checkup with your doctor.) Eventually the heart and body just
can't keep up, and the person experiences the fatigue,
breathing problems or other symptoms that usually prompt a
trip to the doctor.
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