Heart Disease:The Unknown Killer Essay, Research Paper
Table of Contents
I. Introduction
A. Attention Grabber!!!
B. Purpose of the paper
1. To explain how chemistry is part of my life.
II. Body
A. An in depth look at heart disease.
B. Causes and symptoms
C. Explanation on how chemistry is used to treat and in some cases cure heart
disease.
III. Conclusion
A. Recap on how chemistry is part of my life and everyone’s life.
B. Elude to the horrors of a world without chemistry.
IV. Work Cited
V. Self Evaluation
A merciless killer stalks the people of this country. No one can run and no one can
hide, but there is a hope. The application of chemistry in the treatment of heart disease is
the key to ceasing this villain from claiming another victim. Education, though, is the
prerequisite to treating this relentless scourge. People must learn about the symptoms and
causes of heart disease in order to put this nefarious fiend to rest.
Heart diseases have been a major health problem in the United States for years and
are the leading cause of death. Nearly one million people die each year of cardiovascular
disease. Despite these impressive figures, the death rate from cardiovascular diseases has
declined since the mid-1970s, due to modification of risk factors for disease, and
improvements in diagnosis and treatment.
Most heart diseases are associated with inadequate blood supply to body tissue or
overwork of the heart muscle. Heart diseases may be generally classified as congenital or
acquired. Congenital disorders result from abnormal development of the fetal heart.
Acquired disorders of the heart are due to hereditary, environmental, and infectious
processes that damage the heart muscle, the coronary arteries, the heart valves, or the
conduction tissue.
Congenital heart defects complicate approximately 8 of every 1,000 live births.
Infants with heart disease often demonstrate poor feeding and failure to thrive. They may
exhibit respiratory distress with rapid breathing and heart rates of 160 to 200 beats per
minute. They may be ashen or blue in color and perspire excessively. Most of the defects
occur during the first trimester of pregnancy, when formation of the heart and blood
vessels takes place. Maternal infection with German measles (rubella), or alcohol use,
drug use, smoking, exposure to radiation, and genetic disorders have all been implicated as
causative factors.
The most common malformation involves a hole between the two muscular
pumping chambers of the heart, termed a ventricular septal defect. This results in
decreased blood flow to the lungs and mixing between the right and left sides of the heart,
a condition termed cyanosis or blue baby syndrome. The baby has a bluish discoloration
of the lips and skin, which is often more noticeable with crying and activity. Other
common malformations include atrial septal defects, patent ductus arteriosus, and
tetrology of Fallot. These defects cause an imbalance in the normally equal amount of
blood circulated through the right and left sides of the heart. This requires extra work by
the heart, and may eventually lead to heart failure.
The prognosis of infants born with congenital heart disease has markedly improved
in recent decades. More than a dozen of the most commonly occurring congenital heart
defects can now be totally corrected or significantly improved with surgical procedures.
Advances in medical and surgical treatment allow many of these children to lead normal
adult lives.
An example of an acquired disorder is coronary artery disease. The heart is a
functioning muscle and needs oxygen and fuel in order to do its work. It is the job of the
coronary arteries to supply the necessary oxygen and nutrients to the muscle. There are
three major coronary arteries. When these arteries become narrowed or blocked, blood
flow to the muscle is diminished, resulting in angina, a feeling of tightness or pressure in
the chest often associated with shortness of breath. At first, angina may only be evident
during periods of exercise or emotional stress, resolving when the activity ceases. Later, it
may occur even at rest. If the blood flow to an area of the heart completely stops, heart
muscle cells die, resulting in a myocardial infarction, or heart attack. The infarcted area
heals by forming a scar and is no longer a functioning part of heart muscle.
There are many risk factors for coronary artery disease. Smoking and elevated
cholesterol levels are major factors, and obesity, hypertension, and diabetes mellitus have
proven to have adverse effects. A family history of coronary artery disease is also a major
risk factor.
The treatment of coronary artery disease is initially directed toward lifestyle
changes, such as cessation of smoking, moderate exercise, and low-cholesterol diet. If
medical therapy is required, beta blocking or calcium channel blocking agents are utilized
along with nitrates and aspirin. If angina worsens despite medical therapy, a procedure to
revascularize the coronary arteries may be necessary. This may be accomplished by
percutaneous transluminal coronary angioplasty, which opens clogged arteries by dilating
them with tiny balloon catheters, or by coronary artery bypass surgery, where a section of
blood vessel or a prosthesis is implanted to bypass a blockage. An acute myocardial
infarction may be treated early in its evolution by drugs that dissolve blood clots and in
some cases by emergency angioplasty.
Another acquired disorder is valvular heart disease. The heart contains four valves
that allow blood to be pumped in a forward direction through its chambers. Damage to
the heart valves may result from rheumatic fever, bacterial infections, and degeneration
and calcification of the valve as part of the aging process. Bacterial invasion of deformed
heart valves causes a serious heart ailment known as bacterial endocarditis, which was
fatal prior to the development of antibiotic therapy. Valve regurgitation also occurs when
supporting structures of that valve stretch or rupture.
If scar tissue forms on the valves, the tissue may fuse together and obstruct normal
blood flow through the valve, a condition known as stenosis. The valve flaps may also be
scarred in such a way that they cannot close, resulting in regurgitation of blood. Both
stenosis and regurgitation can be detected with a stethoscope as heart murmurs, which are
abnormal heart sounds. Symptoms in valvular heart disease include shortness of breath
and excessive fatigue on exertion. Long-standing valvular dysfunction may result in heart
failure.
Early treatment of valvular heart disease is medical, although balloon catheters can
be used in some situations to dilate stenotic valves. Surgery is usually necessary to replace
or repair the damaged valve as symptoms worsen. Valves may be replaced with
mechanical prostheses, or with valves constructed from animal sources or from another
human. Mechanical valves require the use of blood thinners.
Cardiomyopathy is another acquired disorder. This disease affects the heart
muscle, resulting in inefficient heart function that may eventually lead to heart failure. A
dilated cardiomyopathy results in chamber enlargement and thinning of the myocardium.
This may be the result of muscle damage from infections of viral, bacterial, rickettsial
origin, or from various toxins and drugs, including alcohol. A hypertrophic
cardiomyopathy results from thickening in the heart muscle. This may be an inherited
disorder, or the result of long-standing hypertension. A restrictive cardiomyopathy results
from a stiff, poorly functioning heart.
Heart transplant is one option for patients with endstage cardiomyopathies.
Sometimes, when the lungs are also significantly damaged from endstage heart disease,
heart and lung transplantation is required. A procedure called cardiomyoplasty is
undergoing clinical trials in the United States for the treatment of select patients with
endstage cardiomyopathies. In this procedure the patient’s own skeletal muscle is
wrapped directly around the failing heart and stimulated with a special type of pacemaker.
Yet another acquired disorder is conduction disorders. Conduction disorders are
the result of disturbances in the heart’s pacemaking tissue. An abnormal rhythm, or
arrhythmia, may result in a slow heart rate or rapid heart rate. Arrhythmias may occur in
the atrial or ventricular portions of the heart. Ventricular fibrillation and ventricular
tachycardia are examples of very lethal arrhythmias, which require prompt treatment with
electrical stimulation or antiarrhythmic drugs. Atrial fibrillation is a common arrhythmia; it
can be managed with medical therapy in most cases.
Arrhythmias may require placement of a permanent pacemaker. Newer devices
also detect lethal arrhythmias and deliver an automatic electrical shock to convert the
rhythm back to normal. The management of most arrhythmias involves long-term use of
antiarrhythmic medication. One experimental treatment involves surgical interruption of
abnormal conduction pathways.
In short, heart disease has many forms and many effects. In order for the world to
be rid of this scourge the world must first understand it. Without chemistry the world
would be left to save itself from this affliction. First the citizens of this country must
become aware of the plague which stalks the people. Through that understanding comes
the treatment which will deliver the earth from the hands of this relentless killer.
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