Medical
Management of Vascular Conditions
The
blood vascular system, also called the circulatory
system, of the body is made up of arteries, veins,
and capillaries (tiny blood vessels between arteries
and veins that distribute oxygen-rich blood to
the body). The heart is responsible for pumping
blood through this network of blood vessels throughout
the body.
Another
vascular system of the body is the lymph system.
The lymph vessels carry lymphatic fluid (a clear,
colorless fluid containing water and blood cells).
The lymphatic system helps to protect and maintain
the fluid environment of the body by filtering
and draining lymph away from each region of the
body.
Collectively,
the blood and lymphatic systems are the transport
systems of the body. They supply oxygen, nutrients,
removal of waste products, fluid balance, as well
as many other functions, to all organs and tissues
of the body. Therefore, conditions that affect
the vascular system may affect the organs supplied
by a particular vascular network such as the coronary
arteries of the heart, for example. A blockage
in the coronary arteries of the heart may cause
a heart attack.
A vascular
disease is a condition that affects the arteries
and/or veins. Most often, vascular disease affects
blood flow, either by blocking or weakening blood
vessels, or by damaging the valves that are found
in veins. Organs and other body structures may
be damaged by vascular disease as a result of
decreased or completely blocked blood flow.
There
are many different causes of the various types
of vascular conditions and diseases. However,
coronary artery disease (heart attack), cerebrovascular
disease (stroke), and peripheral arterial disease
(loss of limb or use of limb) are some of the
leading causes of illness and death in the US.
Since there is a potential for the occurrence
of heart attacks, stroke, and loss of limb(s)
to be prevented or decreased, the focus of medical
management of vascular conditions information
will be concentrated on these conditions.
These
three vascular disease conditions (heart attack,
stroke, and peripheral vascular disease) can be
associated with the same cause, atherosclerosis
(a build-up of plaque, which is a deposit of fatty
substances, cholesterol, cellular waste products,
calcium, and fibrin in the inner lining of an
artery), and are all linked to the same risk factors.
Atherosclerosis
is a systemic, progressive, chronic vascular disease
process that particularly affects the carotid
arteries (major blood supply to the brain), coronary
arteries (blood supply to the heart), and the
peripheral arteries in the same manner.
It is
unknown exactly how atherosclerosis begins or
what causes it. Atherosclerosis may start as early
as childhood. However, the disease has the potential
to progress rapidly. It is generally characterized
by the accumulation of fatty deposits along the
innermost layer of the arteries. If the disease
process progresses, plaque formation may take
place. This thickening narrows the arteries and
can decrease blood flow or completely block the
flow of blood to organs and other body tissues
and structures.
The
presence of atherosclerosis in any one of these
areas is a strong indicator that there is also
the presence of atherosclerosis in the arteries
of other parts of the body. Just as atherosclerosis
in the arteries of the heart can cause a heart
attack, or atherosclerosis of the arteries to
the brain can cause a stroke, so can atherosclerosis
of the leg arteries cause a blockage. A blockage
can obstruct blood flow, and potentially result
in pain in the leg(s), ulcers or wounds that do
not heal, and/or the need for amputation (surgical
removal) of the foot or leg.
Therefore,
management of risk factors should be optimized
to control the progression of vascular disease
conditions caused by atherosclerosis. Studies
have shown that lifestyle changes have not only
stopped but also reversed the progression of atherosclerosis
development.
Because
vascular conditions and diseases may involve more
than one of the body's systems at a time,
many types of physicians treat vascular problems.
Specialists in vascular medicine and/or surgery
work closely with physicians in other specialties,
such as internal medicine, interventional radiology,
cardiology, and others to ensure comprehensive
care of patients with vascular conditions.
Modifiable
risk factors that are associated with all four
major vascular conditions are:
- diabetes
- hyperlipidemia (high
levels of fats in the blood, such as cholesterol
and triglycerides)
- smoking
- high blood pressure
- obesity
- lack of exercise
- diet high in saturated
fat
A risk
factor is anything that may increase a person's
chance of developing a disease. It may be an activity,
such as smoking, diet, family history, or many
other things. Different diseases have different
risk factors.
Although
these risk factors increase a person's risk,
they do not necessarily cause the disease. Some
people with one or more risk factors never develop
the disease, while others develop disease and
have no known risk factors. Knowing your risk
factors to any disease can help to guide you into
the appropriate actions, including changing behaviors
and being clinically monitored for the disease.
Medical
management of vascular conditions most often includes
management of modifiable risk factors, such as
diabetes, hyperlipidemia, smoking, and high blood
pressure. An overview of the management of these
four risk factors is given below.
- diabetes
Approximately 65 to 75 percent of
persons with diabetes die from some form of
heart or vascular disease. Diabetes alone, without
the other risk factors, accelerates the rate
of atherosclerosis formation.
Elevated blood glucose levels are associated
with increased risk for heart disease and stroke.
The American Diabetes Association (ADA) recommendations
include maintaining blood glucose levels in
the range of 80 to 120 mg/dl before meals. The
ADA also recommends a blood test called hemoglobin
A1c, which averages blood glucose levels over
a period of several months, to determine if
glucose levels have been controlled. A hemoglobin
A1c level of less than 7 percent is desired.
What
is hemoglobin A1c?
Hemoglobin is a substance
found inside red blood cells. It carries oxygen
for transport to all the cells in the body.
Hemoglobin can also attach itself to glucose.
When too much glucose stays in the bloodstream
for an extended period of time, the glucose
will attach itself to the hemoglobin inside
the red blood cells. The more glucose there
is in the blood stream, the more glucose will
be attached to the hemoglobin. A hemoglobin
A1c blood test will be able to determine the
average glucose level over a period of two to
three months. Elevated hemoglobin A1c levels
are associated with increased risk for cardiovascular
disease.
Your physician will determine the appropriate
medication and care for your specific condition.
Diabetes may be managed with diet and exercise
alone, or with medications, such as oral antihyperglycemic
medications, and/or insulin.
- hyperlipidemia (high
levels of fats in the blood, such as cholesterol
and triglycerides)
Two main types of fats (lipids) are found in
the blood, cholesterol and triglycerides (lipoproteins).
Cholesterol is an essential component found
in all human cell membranes. Triglycerides are
necessary to help transfer energy from food
into body cells.
High levels of low density lipoprotein (LDL)
cholesterol are one of the causes of altered
structure of the innermost layer of the artery's
wall. Elevated LDL levels are associated with
the formation of atherosclerotic plaque (fatty
material that becomes hardened, blocking the
artery and stopping blood flow).
Cholesterol levels may rise and fall based on
the types of fat you eat, the amount of exercise
you do, and your weight. Your physician may
advise you to make changes in your diet as well
as suggest an exercise and weight reduction
plan specific to your needs. In some cases,
there may be a family history of elevated fats
in the blood. Your physician will advise the
best treatment for your particular condition.
Lipid (fat) lowering therapy may be recommended
to help reduce the progression of atherosclerotic
disease. The National Cholesterol Education
Program III (NCEP-III) guidelines recommend
a target goal of LDL cholesterol at less than
130 mg/dl. Recommendations for other types of
fats in the blood include triglycerides less
that 150 mg/dl and high density lipoproteins
(HDL) greater than 40 mg/dl.
Your physician may determine that you require
a medication to maintain a specific cholesterol
level in addition to dietary and exercise changes.
There are several types of medications used
to decrease cholesterol. Statins are a group
of antihyperlipidemic medications, and include
simvastatin (Zocor®), atorvastatin (Lipitor®),
and pravastatin (Pravachol®), among others.
Studies have shown that certain statins can
decrease the thickness of the carotid artery
wall, increase the size of the lumen (opening)
of the artery and reduce vascular inflammation
thought to be a cause of atherosclerosis.
Because atherosclerosis may progress to the
point of narrowing or blocking blood vessels,
another type of medication may be used to prevent
narrowing or blockage caused by blood clots.
Antiplatelet medications (platelets are blood
cells that stick together to prevent bleeding)
may be used to decrease the "stickiness"
of platelets and help prevent blood clots from
forming inside blood vessels. Such medications
include aspirin, clopidogrel (Plavix®),
ticlopidine (Ticlid®), and dipyridamole
(Persantine®).
- smoking cessation
Smoking has been shown to promote the acceleration
of atherosclerotic disease and has been identified
as one of the strongest risk factors in the
development of peripheral artery disease. Smoking
is related to a decreased rate of successful
outcomes in vascular surgical interventions,
an increased amputation rate, and an increased
number of heart attacks and strokes. Smoking
is also related to a decreased rate in survival
of heart attack and stroke victims.
The effects of tobacco include:
- constriction of
blood vessels (as blood vessels become smaller,
the blood pressure is raised)
- increased carbon
monoxide levels in the bloodstream, which
impairs oxygen transport
- formation of blood
clots
- acceleration of
the process of atherosclerosis
- increased risk
of blockage in leg arteries (there is a
30 percent to 50 percent increase with smoking
one-half pack per day)
- cause of heart
attacks, strokes, and/or death
- decreased chance
of successful surgical outcome
- greater risk for
amputation
Smoking cessation has
been shown to decrease the progression of the
atherosclerotic process.
Current guidelines advise all smokers to quit.
If you are unable to quit smoking, your physician
may refer you to a specialist. A specialist
may recommend educational materials, behavior
modification counseling, medications, and follow-up
care. Cessation interventions may also include
support groups or individual counseling, learning
new coping skills, sessions with a specialist
for a prescribed period of time, and/ or nicotine
replacement therapy (NRT). Specific instruction
should be included if nicotine replacement therapy
is started. Non-nicotine medications may also
be used as an alternative or in addition to
other therapies.
Steps to smoking cessation include:
- dispose of all
cigarettes and ash trays before you quit
- seek family and
friends for support
- avoid social situations
which stimulate desire for smoking (drinking
alcohol)
- ask your physician
for referral to a specialist for smoking
cessation
Most insurance plans
cover medications and services for smoking cessation.
In some states, Medicaid will also include coverage
for medications.
In addition, weight gain has been shown to be
minimal after one year of smoking cessation.
The benefits of quitting smoking outweigh the
effects of weight gain.
- high blood pressure
(hypertension)
High blood pressure affects the structure of
the wall of the artery, accelerating the rate
at which atherosclerosis develops.
According to the National Heart, Lung, and Blood
Institute (NHLBI) of the National Institutes
of Health (NIH), high blood pressure for adults
is defined as:
- 140 mm Hg or greater
systolic pressure
and
- 90 mm Hg or greater
diastolic pressure
In an update of NHLBI
guidelines for hypertension in 2003, a new blood
pressure category was added called pre-hypertension:
- 120 mm Hg - 139
mm Hg systolic pressure
and
- 80 mm Hg - 89
mm Hg diastolic pressure
The new NHLBI guidelines
now define normal blood pressure as follows:
- Less than 120
mm Hg systolic pressure
and
- Less than 80 mm
Hg diastolic pressure
These numbers should
be used as a guide only. A single elevated blood
pressure measurement is not necessarily an indication
of a problem. Your physician will want to see
multiple blood pressure measurements over several
days or weeks before making a diagnosis of hypertension
(high blood pressure) and initiating treatment.
A person who normally runs a lower-than-usual
blood pressure may be considered hypertensive
with lower blood pressure measurements than
140/90.
Weight loss, regular physical exercise, and
balanced diet has shown to be effective in lowering
high blood pressure. A weight loss of about
five percent of total body weight may lower
the blood pressure and cause blood pressure
medications to be more effective. Exercise for
approximately 30 to 45 minutes (such as brisk
walking) on most days of the week has been shown
to decrease blood pressure.
Blood pressure medications may be used to help
control elevated blood pressure. Your physician
will prescribe the appropriate medication(s)
for your situation. There are several types
of medications which act in different ways to
lower blood pressure.
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