| Atherosclerosis
What is atherosclerosis?
Atherosclerosis is a type of arteriosclerosis caused by a build-up
of plaque in the inner lining of an artery. (Arteriosclerosis is a
general term for thickening or hardening of the arteries.) Plaque
is made up of deposits of fatty substances, cholesterol, cellular
waste products, calcium, and fibrin, and can develop in medium or
large arteries. The artery wall becomes thickened and looses its elasticity.
Atherosclerosis is a slow, progressive disease that
may start as early as childhood. However, the disease has the potential
to progress rapidly.
What causes atherosclerosis?
It is unknown exactly how atherosclerosis begins
or what causes it. Some scientists think that certain risk factors
may be associated with atherosclerosis, including:
- elevated cholesterol and triglyceride levels
- high blood pressure
- smoking
- diabetes mellitus (type 1 diabetes)
- obesity
- physical inactivity
How does the disease progress?
There is a gradual build-up of plaque or thickening of the inside
of the walls of the artery, causing a decrease in the amount of blood
flow, and a decrease in the oxygen supply to the vital body organs
and extremities.
A heart attack may occur if the oxygenated blood supply is reduced
to the heart. A stroke may occur if the oxygenated blood supply is
cut off to the brain. Gangrene may occur if the oxygenated blood supply
is reduced to the arms and legs.
What are the symptoms of atherosclerosis?
Signs and symptoms of atherosclerosis may develop gradually, and may
be few, as the plaque builds up in the artery. Symptoms may also vary
depending on the affected artery. However, when a major artery is
blocked, signs and symptoms may be severe, such as those occurring
with heart attack, stroke, aneurysm, or blood clot.
The symptoms of atherosclerosis
may resemble other cardiac conditions. Consult your physician for
a diagnosis.
How is atherosclerosis diagnosed?
In addition to a complete medical
history and physical examination, diagnostic procedures for atherosclerosis
may include any, or a combination of, the following:
- coronary arteriogram (or angiogram) - with this
procedure, x-rays are taken after a contrast agent is injected into
an artery -- to locate the narrowing, occlusions, and other abnormalities
of specific arteries.
- Doppler sonography - a special transducer is used to direct sound
waves into a blood vessel to evaluate blood flow. An audio receiver
amplifies the sound of the blood moving though the vessel. Faintness
or absent of sound may indicate an obstruction in the blood flow.
- blood pressure comparison - comparing blood pressure measurements
in the ankles and in the arms to determine any constriction in blood
flow. Significant differences may indicate a narrowing of vessels
which could be caused by atherosclerosis.
-
MUGA/radionuclide angiography
- a nuclear scan to see how the heart wall moves and how much
blood is expelled with each heartbeat, while the patient is at
rest.
-
thallium/myocardial perfusion
scan - a nuclear scan given while the patient is at rest or after
exercise that may reveal areas of the heart muscle that are not
getting enough blood.
Treatment for atherosclerosis:
Specific treatment will be determined by your physician based on:
- your age, overall health, and medical history
- extent of the disease
- the location of the blockage
- the patients signs and symptoms
- your tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- your opinion or preference
Treatment may include:
- lifestyle modifications to control risk factors, including regular
exercise, proper nutrition, and smoking cessation
- coronary angioplasty
- with this procedure, a catheter is used to create a bigger opening
in the vessel to increase blood flow. Although angioplasty is performed
in other blood vessels, Percutaneous Transluminal Coronary Angioplasty
(PTCA) refers to angioplasty in the coronary arteries to permit
more blood flow into the heart. There are several types of PTCA
procedures, including:
- balloon angioplasty - a small balloon
is inflated inside the blocked artery to open the blocked area.
- atherectomy - the blocked area
inside the artery is "shaved" away by a tiny device
on the end of a catheter.
- laser angioplasty - a laser used to
"vaporize" the blockage in the artery.
- coronary artery stent - a tiny coil
is expanded inside the blocked artery to open the blocked area
and is left in place to keep the artery open.
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