Coronary
Heart Disease
Coronary
arteries supply blood to the heart muscle. Like
all other tissues in the body, the heart muscle
needs oxygen-rich blood to function, and oxygen-depleted
blood must be carried away. The coronary arteries
consist of two main arteries: the right and left
coronary arteries. The left coronary artery system
branches into the circumflex artery and the left
anterior descending artery.
The
two main coronary arteries are the left and right
coronary arteries. The left coronary artery (LCA),
which divides into the left anterior descending
artery and the circumflex branch, supplies blood
to the left ventricle and left atrium. The right
coronary artery (RCA), which divides into the
right posterior descending and acute marginal
arteries, supplies blood to the right ventricle,
right atrium, and sinoatrial node (cluster of
cells in the right atrial wall that regulates
the heart's rhythmic rate), and atrioventricular
node (AV node, a cluster of cells between the
atria and ventricles that regulate the electrical
current).
Additional
arteries branch off the two main coronary arteries
to supply the heart muscle with blood. These include
the following:
- circumflex artery
(Cx)
The circumflex artery branches off the left
coronary artery and encircles the heart muscle.
This artery supplies blood to the lateral side
and back of the heart.
- left anterior descending
artery (LAD)
The left anterior descending artery branches
off the left coronary artery and supplies blood
to the front of the left side of the heart.
Smaller
branches of the coronary arteries include: acute
marginal, posterior descending (PDA), obtuse marginal
(OM), septal perforator, and diagonals.
Since
coronary arteries deliver blood to the heart muscle,
any coronary artery disorder or disease can have
serious implications by reducing the flow of oxygen
and nutrients to the heart, which may lead to
a heart attack and possibly death. Atherosclerosis
(a build-up of plaque in the inner lining of an
artery causing it to narrow or become blocked)
is the most common cause of heart disease.
Coronary
heart disease, or coronary artery disease (CAD),
is characterized by the accumulation of fatty
deposits along the innermost layer of the coronary
arteries. The fatty deposits may develop in childhood
and continue to thicken and enlarge throughout
the life span. This thickening, called atherosclerosis,
narrows the arteries and can decrease or block
the flow of blood to the heart.
Nearly
13 million Americans suffer from coronary artery
disease - the number one killer of both men and
women in the US.
Risk
factors for CAD often include:
- high LDL cholesterol,
high triglycerides levels and reduced HDL
cholesterol
- high blood pressure
(hypertension)
- physical inactivity
- smoking
- obesity
- high saturated fat
diet
Controlling
risk factors is the key to preventing illness
and death from CAD.
The
symptoms of coronary heart disease will depend
on the severity of the disease. Some persons with
CAD have no symptoms, some have episodes of mild
chest pain or angina, and some have more severe
chest pain.
If too
little oxygenated blood reaches the heart, a person
will experience chest pain called angina. When
the blood supply is completely cut off, the result
is a heart attack, and the heart muscle begins
to die. Some persons may have a heart attack and
never recognize the symptoms. This is called a
"silent" heart attack.
When
symptoms are present, each person may experience
them differently. Symptoms of coronary artery
disease may include:
- heaviness, tightness,
pressure, and/or pain in the chest - behind
the breastbone
- pain radiating in the
arms, shoulders, jaw, neck, and/or back
- shortness of breath
- weakness and fatigue
In addition
to a complete medical history and physical examination,
diagnostic procedures for coronary artery disease
may include any, or a combination of, the following:
- electrocardiogram
(ECG or EKG) - a test that records the electrical
activity of the heart, shows abnormal rhythms
(arrhythmias or dysrhythmias), and detects heart
muscle damage.
- stress test (usually
with ECG; also called treadmill or exercise
ECG) - a test that is given while a patient
walks on a treadmill to monitor the heart during
exercise. Breathing and blood pressure rates
are also monitored. A stress test may be used
to detect coronary artery disease, and/or to
determine safe levels of exercise following
a heart attack or heart surgery.
- 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.
- nuclear scanning -
radioactive material is injected into a vein
and then is observed using a camera as it is
taken up by the heart muscle. This indicates
the healthy and damaged areas of the heart.
Specific
treatment will be determined by your physician
based on:
- your age, overall health,
and medical history
- extent of the disease
- your tolerance for
specific medications, procedures, or therapies
- expectations for the
course of the disease
- your opinion or preference
Treatment
may include:
- controlling risk factors
(the most effective way to stop the progression
of CHD)
- changing to a low-fat
diet
- losing weight (if
overweight)
- establishing and
maintaining an appropriate exercise program
- quitting smoking
- controlling blood
sugar if diabetic
- medication
- 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.
- 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.
- atherectomy - the
blocked area inside the artery is cut 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 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.
Click
here to view the Online
Resources of Cardiovascular Disease
|
