The Noninvasive Heart Center
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HEART DISEASE GLOSSARY


INDEX

ACE Inhibitors

Alpha Blockers

Alternative Medical Treatment

Aneurysm

Angina Pectoris

Angiotensin Receptor Blockers

Apexcardiogram

Arteriosclerosis

Beta Blockers

CAT Scanning

Calcium Channel Blockers

Collateral Vessels

Coronary Angiogram

Coronary angioplasty

Coronary artery bypass surgery

Coronary artery disease

Coronary heart disease

Diuretics

Doppler echocardiography

Echocardiogram

Electrocardiogram

Heart Murmur

Heart attack

Heart failure

Holter Monitoring

Hypertension

Ischemia

Magnetic Resonance Imaging or MRI

Myocardial infarction

Myocardium

NSAID drugs

Nitrates

Nitroglycerine

Noninvasive Tests

Noninvasive cardiologist

Phonocardiogram

Positron Emission Tomography or PET

Radioactive Imaging

Risk factor

Stent

Systolic and Diastolic Time Intervals

Ventricular septum


Alternative Medical 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 ischemic.

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 infarction.

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, and stress.

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 of symptoms.

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.

Angiotensin Receptor 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 reduced.

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 circulation.

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.