Coronary Heart Disease
The heart, just like any other organ, requires blood to supply it with oxygen and other nutrients so that it can
do its work. The heart does not extract oxygen and other nutrients from the blood flowing inside it. The heart
gets its blood from the coronary arteries which travel around the surface of the heart and eventually carry
blood within the heart muscle. Approximately 5% of the blood from the heart goes to the coronary arteries.
Coronary artery disease is caused by a blockage in one of
the coronary arteries. When a coronary artery is partially
blocked, that artery cannot supply enough blood to the
heart muscle to meet its needs. A heart attack occurs when
a coronary artery is completely blocked and no blood or
oxygen is getting to the heart muscle served by that artery.
This causes that particular part of the heart muscle to die.
(more info later)
What causes Coronary Heart Disease (CHD)?
CHD is caused when there is a high level of
cholesterol, a fat-like substance, in the blood.
Cholesterol and fat, circulating in the blood, build up
on the walls of the arteries. The buildup narrows the
arteries and can slow or block the flow of blood.
When the level of cholesterol in the blood is high,
there is a greater chance that it will be deposited
onto the artery walls. This process begins in most
people during childhood and the teenage years, and
worsens as they get older.
Who is at risk for CHD?
Risk factors are conditions that increase your risk
of developing heart disease. Some can be changed
or controlled and some cannot. Although these
factors each raise your risk of CHD, they are not
the only things that can cause coronary heart
disease. Just as important is that even with none
of these risk factors, you might still develop CHD.
Controllable Risk Factors
High blood pressure
High blood cholesterol
Smoking
Obesity
Physical inactivity
Diabetes
Uncontrollable Risk Factors
Gender
Age
Heredity (family history)
What are the symptoms of CHD?
Chest pain or shortness of breath may be the earliest signs of CHD. A person may feel heaviness, tightness,
pain, burning, pressure, or squeezing, usually behind the breastbone, but sometimes also in the arms, neck, or
jaws. These signs usually bring the patient to a doctor for the first time. Nevertheless, some people have heart
attacks without ever having any of these symptoms.
It is important to know that there is a wide range of severity for CHD. Some people have no symptoms at all,
some have mild intermittent chest pain, and some have more pronounced and steady pain. Still others have
CHD that is severe enough to make normal everyday activities difficult.
Coronary Heart Disease can lead to a heart attack
A heart attack occurs when blood flow to a part of your heart is blocked for a long enough time and that part
of the heart muscle is damaged or dies. Your doctor calls this a myocardial infarction.
Symptoms of a heart attack include:
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Discomfort, pressure, heaviness, or pain in the
chest, arm, or below the breastbone
Discomfort radiating to the back, jaw, throat,
or arm
Fullness or indigestion (may feel like
heartburn)
Sweating, nausea, vomiting, or dizziness
Extreme weakness, anxiety, or shortness of
breath
Rapid or irregular heartbeats
Women's major symptoms prior to their heart attack
included:
Unusual fatigue
Sleep disturbance
Shortness of breath
Indigestion
Anxiety
Women’s major symptoms during the heart attack
include:
Shortness of breath
Weakness
Unusual fatigue
Cold sweat
Dizziness
During a heart attack, symptoms may last 30 minutes or longer and are not relieved by rest or nitroglycerin
under the tongue. Some people have a heart attack without having any symptoms (a "silent" heart attack).
Once heart attack is diagnosed, treatment should begin immediately – at the site or possibly in the ambulance
or emergency room. With each passing minute after a heart attack, more heart tissue loses oxygen and
deteriorates or dies. The main way to prevent heart damage is to restore blood flow quickly.
A heart attack can lead to heart failure. This is when the amount of damaged tissue in your heart is so great
that the remaining heart muscle can't do an adequate job of pumping blood out of your heart. This decreases
blood flow to tissues and organs throughout your body and may produce shortness of breath, fatigue, and
swelling in your ankles and feet. Heart failure may be a temporary problem that goes away after your heart,
which has been stunned by a heart attack, recovers over a few days to weeks. However, it can also be a
chronic condition resulting from extensive and permanent damage to your heart following your heart attack.
What are the tests for CHD?
There is no one simple test--some or all of the following procedures may be needed. These diagnostic
procedures are used to establish CHD, to determine its extent and severity, and to rule out other possible
causes of the symptoms.
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An electrocardiogram (ECG or EKG) is a graphic record of the electrical activity of the heart as it contracts
and rests. Abnormal heartbeats and some areas of damage, inadequate blood flow, and heart enlargement
can be detected on the records.
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A stress test (also called a treadmill test or exercise ECG) is used to record the heartbeat during exercise.
This is done because some heart problems only show up when the heart is working hard. In the test, an
ECG is done before, during, and after exercising on a treadmill; breathing rate and blood pressure may be
measured as well.
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Nuclear scanning is sometimes used to show damaged areas of the heart and expose problems with the
heart's pumping action. A small amount of radioactive material is injected into a vein, usually in the arm. A
scanning camera records the nuclear material that is taken up by heart muscle (healthy areas) or not taken
up (damaged areas). (B)
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Coronary angiography (or arteriography) is a test used to explore the coronary arteries. A fine tube
(catheter) is put into an artery of an arm or leg and passed through the tube into the arteries of the heart.
The heart and blood vessels are then filmed while the heart pumps. The picture that is seen, called an
angiogram or arteriogram, will show problems such as a blockage caused by atherosclerosis. (A)
(A)
(B)
What types of surgery are used to treat CHD?
Many patients can control CHD with lifestyle changes and medication. Surgery may be recommended for
patients who continue to have frequent or disabling angina despite the use of medications, or people who
have severe blockages in their coronary arteries.
Balloon angioplasty (A) (with or without a coronary stent) begins with a procedure similar to that described
under angiography. However, the catheter positioned in the narrowed coronary artery has a tiny balloon at its
tip. The balloon is inflated and deflated to stretch or break open the narrowing and improve the passage for
blood flow. The balloon-tipped catheter is then removed. A coronary artery stent (B) is a small, metal mesh
tube that is placed inside a coronary artery to help keep the artery open. The stent is inserted along with the
balloon catheter and expands when the balloon is inflated. The stent is left there to help keep the artery open.
In a coronary artery bypass operation (C), a blood vessel, usually taken from the leg or chest, is grafted onto
the blocked artery to bypass the blocked area. If more than one artery is blocked, a bypass can be done on
each. The blood then goes around the obstruction to supply the heart with enough blood to relieve chest pain.
(A)
(B)
(C)