HEART DISEASE GLOSSARY
Alternative Medical Treatment
Angiotensin Receptor Blockers
Calcium Channel Blockers
Coronary artery bypass surgery
Coronary artery disease
Coronary heart disease
Magnetic Resonance Imaging or MRI
Positron Emission Tomography or PET
Systolic and Diastolic Time Intervals
Treatment: Alternative Medical treatment generically refers to any
treatment that is different than the most commonly used treatment for an
illness. Because interventional treatments such as bypass surgery,
angioplasty and the insertion of
stents have become the most popular forms of treatment for
coronary artery disease (but certainly not the only or even the best form of
treatment), medical treatment of coronary artery disease with drugs is often
incorrectly referred to as alternative medical therapy. In fact, the most
common form of treatment for coronary artery disease throughout the world is
medical therapy with modern drugs. Only in the United States where there is
fee for service health care delivery has bypass surgery and angioplasty become
more popular. Thus medical therapy with modern drugs is simply another
accepted way of treating heart disease, but because it is not as economically
rewarding to the doctor, medical clinic or hospital, it is not the first form
of treatment recommended. Alternative treatment for heart disease then can be
defined as forms of treatment other than medical treatment, bypass surgery and
angioplasty for coronary artery disease. These would include chelation
therapy, herbs, food supplements, meditation, antioxidants, vitamins, enhanced
counter pulsation and acupuncture among others.
Aneurysm: A ballooning out of an artery in an
area where the arterial wall has become weakened. Over a period of years the
aneurysm will gradually expand and eventually rupture. If it is an aortic
aneurysm, death will occur quickly. If it is a brain aneurysm, the victim will
have a stroke.
Angina Pectoris: A unique kind of chest
discomfort often described as a heaviness, tightness, aching, or feeling that
the chest is in a vise. It is usually, but not always, due to coronary artery
disease in which the narrowing of the coronary artery is great enough to cause
ischemia to the heart muscle. The most common cause of
angina like chest pain is hypertension.
Arteriosclerosis: The gradual buildup of
plaque along the inside wall of an artery. Contrary to what you may have read
or been told, less than 5% of a plaque is made up of cholesterol. The remainder
consists of clot-like material and various cells. If the plaque occludes more
than 50% of the arterial lumen (opening), then it may interfere with the flow
of blood. A heart attack is believed to be due to the rupture of a plaque in
one of the coronary arteries followed by bleeding and the formation of a clot.
If the clot completely blocks the artery, the victim may have a myocardial
infarction (heart attack).
Collateral Vessels: When a coronary
artery becomes narrowed, under a process known as angiogenesis (angio=blood
vessels, genesis=birth of), new vessels will bud out from the obstructed artery
like branches from a tree, upstream from the obstruction, and reinsert into the
obstructed artery downstream from the obstruction, or they may connect up with
a nearby healthy artery, allowing the blood flow to reach the heart muscle.
These new vessels are known as collateral vessels. In a sense, the heart puts
in its own bypasses.
Coronary artery disease: The
development of arteriosclerotic plaque within the coronary arteries on the
surface of the heart. When the artery is sufficiently narrowed, blood flow to
the heart muscle may be reduced and the muscle (myocardium) may become
Coronary Angiogram: An invasive test in
which a plastic tube called a catheter in inserted in the main artery in the
thigh (femoral artery) and pushed up the aorta till it reaches the heart. The
catheter is then inserted into the coronary arteries as the aorta exits from
the heart. X-ray opaque dye is injected under high pressure and high-speed
x-rays are taken. The artery and its branches can then be imaged. If the
artery is narrowed or obstructed, its location can be identified.
Coronary angioplasty: A catheter with
a balloon at the tip is passed into a coronary artery to where it is narrowed
and the balloon is inflated with 2-15 atmospheres of pressure. (You have 2
atmospheres of pressure in your automobile tires. The hope is the artery will
be expanded where it is narrowed. In the process, the arterial wall is often
damaged and sometimes it is perforated.
Coronary artery bypass
surgery: A vein from the leg, or an artery from beneath the breastbone
is connected to the obstructed coronary artery upstream and downstream from the
obstruction allowing blood to flow around the obstruction. Such bypasses
frequently become obstructed themselves over time.
Coronary heart disease: Direct
damage to the heart muscle of a degree sufficient to interfere with the
function of the heart. This may result from a marked reduction in blood flow
to the heart muscle as a result of narrowing due to coronary artery disease, or
from complete blockage of the artery that occurs during a heart attack
(myocardial infarction). If the amount of damage or area of impaired function
is not too large, it may not interfere with the total function of the heart.
If there is extensive damage to the heart muscle (usually from multiple heart
attacks), the heart may become so weak that heart failure will develop. It is
important to note that a victim may have coronary artery disease but not
coronary heart disease because of the development of collateral vessels around
the narrowed coronary artery.
Heart attack: It is currently believed that
when an arteriosclerotic plaque ruptures, it may cause the blood in a coronary
artery to clot on the surface of the plaque. If the clot is large enough, it
will occlude the artery and block the flow of blood to the heart muscle. This
will damage or even destroy the heart muscle if there are not enough collateral
blood vessels to carry the blood around the occluded vessel.
Heart failure: After multiple heart attacks,
the heart becomes very enlarged and stretched out and loses its elasticity. It
becomes so weak it cannot function or contract enough to supply the body's
needs. When this happens the patient is said to be in heart failure.
Heart Murmur: A sound within the heart's
chambers due to the turbulence of blood as it passes through a damaged valve.
Hypertension: The old definition is a
sustained elevation of blood pressure to abnormal levels (above 135/85).
Because it is possible to have hypertension with a normal blood pressure, a
more correct definition is that the victim develops an abnormal increase in
blood pressure when subjected to stress or exertion.
Ischemia: A generic term meaning reduced blood
flow to a given area. Ischemia to the brain can result in fainting. If
prolonged it will cause a stroke. Ischemia to the myocardium (heart muscle),
will cause angina pectoris. If prolonged, it will produce a myocardial
Myocardial infarction: (See Heart attack)
Myocardium: The wall of the heart is made up of
three layers: An outer layer called the pericardium. It is a tough membrane
like covering to protect the heart from expanding. Unfortunately it may
interfere with the flow of blood in the coronary arteries. The middle layer is
the thick heart muscle that is uniquely designed to contract in a circular
fashion in order to squeeze blood into the circulation approximately once a
second. It is this layer that is called the myocardium. The myocardium is
lined with a smooth layer of tissue known as the endocardium. It is in direct
contact with the blood within the heart's chambers and prevents the blood from
clotting inside of the heart.
Risk factor: Conditions or diseases that
increase the likelihood of heart disease. Examples are hypertension, diabetes,
Stent: This is a short, expandable tube manufactured
to serve as a coiled metal scaffolding that is inserted into a narrowed artery.
The tube is expanded at the point of narrowing in the hope of keeping the walls
apart. Unfortunately, the blood within the tube often clots, or tissue
overgrowth will fill the tube and block it, or the stent may move downstream.
Ventricular septum: The muscular wall
that divides the heart's chambers into the left and right ventricles.
Noninvasive cardiologist: A
cardiologist who diagnoses and treats heart disease using the
noninvasive tests listed below. None
of the noninvasive tests require the insertion of tubes or catheters inside of
the body. In addition, whenever possible the patient with heart disease is
also treated noninvasively using the drugs
listed below. Interventions such as bypass surgery, angioplasty and the
insertion of stents are never employed unless medical treatment is
unsuccessful, which is rare.
Noninvasive Tests: Noninvasive tests are
a group of tests that involves the placing of radioactive detectors, sonar
devices, electronic sensors, pulse transducers, and microphones on the surface
of the chest over the heart---not all at once but one at a time. No catheters,
tubes or needles enter or "invade" the body. Such tests image and permanently
record the structure and function of the heart during both contraction and
relaxation. See below for the kind of information that may be obtained from
each noninvasive test. The information derived from noninvasive tests allows
early discovery of heart disease, or its progression, the detection of
complications before symptoms appear, the identification of patients who are at
high risk for a future heart attack, and the effectiveness and optimal dosages
of drugs used in treatment. Once heart disease is found then predisposing
conditions that accelerate its progression can be identified, treated and
eliminated. Drugs which protect the heart and improve its blood supply and
function can be given. The same noninvasive tests used for early diagnosis may
be utilized to monitor the patient's progress. These can be compared with
previous tests in order to optimize treatment, and to detect and treat adverse
changes even before complications occur.
Specific Noninvasive Tests
Electrocardiogram: A recording of the
electrical output of the heart. It becomes abnormal only when there is
advanced heart disease. It cannot detect early heart disease and may even be
normal during a heart attack. It does not provide information about the
function of the heart anymore than measuring the voltage from a car battery
will reflect the performance of a car.
Echocardiogram: A test used to detect heart
disease based upon the principle of sonar or radar, and similar to the sonogram
used in pregnancy. High frequency sound waves are transmitted to the inside of
the heart. These waves are reflected from the various interfaces within the
heart and provides moving images of its muscular walls. Therefore, an
echocardiogram can determine whether there are localized abnormalities of
contraction or impaired blood flow due to obstructive coronary artery disease,
whether the heart muscle is thickened due to hypertension or thinned from a
prior heart attack, whether the dimensions of the heart's chambers are
increased from an overload, the structure and motion of the valves as they open
and close, whether there is obstruction or leakage of those valves, and the
velocity of blood flow in all four cardiac chambers as it fills and empties. If
the blood flow is reduced to an area of heart due to an obstruction of a
coronary artery, the motion of the ischemic muscle will be different than
normal. If, however, collateral vessels are present, the muscle will function
normally even though an angiogram shows a severely narrowed artery.
Doppler echocardiography: this
procedure is performed simultaneously with an echocardiogram and provides
information about the velocity of blood flow within the heart's chambers and
the direction it is traveling. Thus it helps doctors detect the origin of a
heart murmur, and whether a valve is obstructed or leaking or both. Newer
Doppler technologies allow the measurement of the velocity of contraction of
the heart muscle itself. Damaged or ischemic muscle contracts and relaxes more
slowly than normal muscle.
Radioactive Imaging: These tests
entail the injection of a radioactive substance (Thallium) into the circulation
both at rest and during exercise. In theory, if there is no obstruction to
blood flow in the coronary arteries then there will be equal and uniform
distribution of the radioactive material. If there is an obstruction to flow,
there will a decrease or no radioactivity in a given area of the heart. Such
an area would be considered ischemic.
Holter Monitoring: A series of EKG
electrodes are attached to the chest for 24 hours. In a sense this is a
continuous EKG over a 24 hour period. Individuals with obstructive coronary
artery disease often have silent ischemia during stress of daily activities
that would not be seen on an office EKG. Holter monitoring allows detection of
coronary artery disease that might otherwise be missed because of the absence
Positron Emission Tomography
or PET: A type of radioactive imaging test that measures the metabolism
of certain radioactive labeled substances in heart muscle. If heart muscle is
damaged or not functioning normally because it is ischemic, its metabolism will
be impaired and this can be determined by PET studies.
Magnetic Resonance Imaging or
MRI: Magnetic resonance imaging, which is widely used to study the
anatomy of many areas of the body, also can be used to study the heart. It
provides anatomical rather than functional information. Newer methods even
allow the study of blood flow in the coronary arteries.
CAT Scanning: CAT scanning, a well-known
x-ray technique, also can be used to determine if there is calcium in the
coronary arteries. If calcium is present it is presumptive evidence that the
artery is narrowed.
Apexcardiogram: This is a muscle cardiogram
of the pattern of contraction and relaxation of the heart's muscle. This test
will provide information about the rate and amount of filling of the heart, and
whether it is contracting normally. Much simpler (and less expensive) than the
previously noted tests, it is extremely sensitive in the early detection of
hypertension and heart disease, and provides serial information about the
progression of the patient's disease.
Systolic and Diastolic Time
Intervals: Like the apexcardiogram, this test is simple and inexpensive
to perform, and measures the duration of each phase of the cardiac cycle. When
used in conjunction with the apexcardiogram and
the phonocardiogram it will measure the duration
of the electrical activation of the heart, how long it takes for pressure to
develop with in the heart's chambers (analogous to how long an automobile takes
to go from 0 to 60 miles an hour), how long it takes for blood to be ejected
from the heart with each heartbeat, the time required for the heart to relax
and to fill with blood, and the duration of contraction of the left atrium.
Together, this data provides a composite of the functional abilities of the
heart during each phase of its contraction and relaxation. Thus, failure or
impairment of the heart's component functions will be detected long before
impairment of total function.
Phonocardiogram: This is a high fidelity
sound recording of the sounds and murmurs made by the heart. It allows the
detection of subaudible sounds and murmurs, and makes a permanent record of
these events. In contrast, the ordinary stethoscope cannot detect such sounds
or murmurs, and provides no record of their occurrence. The ability to
quantitate the sounds made by the heart provides information not readily
available from more sophisticated tests, and provides vital information about
the effects of certain cardiac drugs upon the heart. It is also an effective
method for tracking the progress of the patient's disease.
Commonly Used Drugs
ACE Inhibitors: Technically, angiotensin
converting enzyme inhibitors. A class of drug that lowers blood pressure by
blocking the formation of a neurohormone known as angiotensin.
Alpha Blockers: A class of drugs that lower
blood pressure by dilating the peripheral blood vessels.
Blockers: These are drugs that accomplish the same thing as the Ace
inhibitor inhibitors but through a different mechanism of action.
Beta Blockers: Beta blockers are a class of
heart drugs that block the effect of adrenaline on the heart. There the heart
rate will not increase during stress, and the workload of the heart will be
Calcium Channel Blockers: A class
of drugs that lower blood pressure and increase coronary blood flow.
Diuretics: A class of drugs that eliminate
excess fluid from the body and help to lower blood pressure.
Nitrates: These are a class of drugs that
increase the blood flow to the heart muscle and reduce the workload on the
heart by causing substantial amounts of blood to pool on the venous side of the
Nitroglycerine: A nitrate like drug that
can be placed beneath the tongue to rapidly dilate the coronary arteries to
increase the blood flow within those arteries.
NSAID drugs: Anti-inflammatory drugs that work
like cortisone although they are not. They are potentially dangerous to heart
patients because they cause marked fluid retention.