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 loses its elasticity.
Atherosclerosis
is a slow, progressive disease that may start
as early as childhood. However, the disease has
the potential to progress rapidly.
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
- high saturated fat
diet
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.
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.
In addition
to a complete medical history and physical examination,
diagnostic procedures for atherosclerosis may
include any, or a combination of, the following:
- cardiac catheterization
- 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 absence 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.
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
- your 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.
- coronary artery bypass
Most commonly referred to as simply "bypass
surgery," this surgery is often performed
in people who have angina (chest pain) and coronary
artery disease (where plaque has built up in
the arteries). During the surgery, a bypass
is created by grafting a piece of a vein above
and below the blocked area of a coronary artery,
enabling blood to flow around the obstruction.
Veins are usually taken from the leg, but arteries
from the chest may also be used to create a
bypass graft.
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