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February 10, 2012

Premature Ventricular Contractions (PVCs) Glossary of Terms

The following are health and medical definitions of terms that appear in the Premature Ventricular Contractions (PVCs) article.

Abnormal: Not normal. Deviating from the usual structure, position, condition, or behavior. In referring to a growth, abnormal may mean that it is cancerous or premalignant (likely to become cancer).

Acute: Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care.
See the entire definition of Acute

Adrenaline: A substance produced by the medulla (inside) of the adrenal gland, adrenaline (the official name in the British Pharmacopoeia) is synonymous with epinephrine. Technically speaking, adrenaline is a sympathomimetic catecholamine. It causes quickening of the heart beat, strengthens the force of the heart's contraction, opens up the bronchioles in the lungs and has numerous other effects. The secretion of adrenaline by the adrenal is part of the "fight-or-flight" reaction that we have in response to being frightened.

Amphetamine: A drug with a stimulant effect on the central nervous system that can be both physically and psychologically addictive when overused. This drug has been much abused recreationally. The street term "speed" refers to stimulant drugs such as amphetamine.

Angiogram: An x-ray of blood vessels which can be seen because the patient receives an injection of dye to outline the vessels on the x-ray.

Antidepressants: Anything, and especially a drug, used to prevent or treat depression.
See the entire definition of Antidepressants

Artery: A vessel that carries blood high in oxygen content away from the heart to the farthest reaches of the body. Since blood in arteries is usually full of oxygen, the hemoglobin in the red blood cells is oxygenated. The resultant form of hemoglobin (oxyhemoglobin) is what makes arterial blood look bright red.
See the entire definition of Artery

Asymptomatic: Without symptoms. For example, an asymptomatic infection is an infection with no symptoms.

Atria: The plural of atrium. The atria are the two smaller chambers of the heart. Each atrium consists of an open space with recessed walls.
See the entire definition of Atria

Atrial: Pertaining to the atria, the upper chambers of the heart, as in atrial fibrillation and atrial septal defect.

Atrial fibrillation: Abnormal irregular heart rhythm with chaotic generation of electrical signals in the atria of the heart. Familiarly called atrial fib.

Atrial flutter: Well-organized but overly rapid contractions of the atrium of the heart (usually at a rate of 250-350 contractions per minute).
See the entire definition of Atrial flutter

Atrium: One of the two smaller chambers of the heart. Each atrium consists of an open space with recessed walls. The plural of atrium is atria.
See the entire definition of Atrium

AV node: An electrical relay station between the atria (the upper) and the ventricles (the lower chambers of the heart). Electrical signals from the atria must pass through the AV node to reach the ventricles.
See the entire definition of AV node

Benign: Not cancer. Not malignant. A benign tumor does not invade surrounding tissue or spread to other parts of the body. A benign tumor may grow but it stays put (in the same place).
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Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".

Brain: That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."

Caffeine: A stimulant found naturally in coffee beans, tea leaves, cocoa beans (chocolate) and kola nuts (cola) and added to soft drinks, foods, and medicines. A cup of coffee has 100-250 milligrams of caffeine. Black tea brewed for 4 minutes has 40-100 milligrams. Green tea has one-third as much caffeine as black tea.
See the entire definition of Caffeine

Cardiac: Having to do with the heart.

Cardiac output: The amount of blood that is pumped by the heart per unit time, measured in liters per minute (l/min).
See the entire definition of Cardiac output

Cardiomyopathy: Disease of the heart muscle (the myocardium). From the Greek roots: "cardio-", heart + "mys", muscle + "pathos", disease = disease (of the) heart muscle.

Cardiovascular: The circulatory system comprising the heart and blood vessels which carries nutrients and oxygen to the tissues of the body and removes carbon dioxide and other wastes from them.
See the entire definition of Cardiovascular

Cardiovascular disease: Disease affecting the heart or blood vessels.
See the entire definition of Cardiovascular disease

Chest: The area of the body located between the neck and the abdomen. The chest contains the lungs, the heart and part of the aorta. The walls of the chest are supported by the dorsal vertebrae, the ribs, and the sternum.
See the entire definition of Chest

Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time.
See the entire definition of Chronic

Cocaine: The most potent stimulant of natural origin, a bitter addictive anesthetic (pain blocker) which is extracted from the leaves of the coca scrub (Erythroxylon coca) indigenous to the Andean highlands of South America.
See the entire definition of Cocaine

Congestive heart failure: Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart.
See the entire definition of Congestive heart failure

Contraction: The tightening and shortening of a muscle.

Contusion: Another name for a bruise. What is a bruise ? A bruise, or contusion, is caused when blood vessels are damaged or broken as the result of a blow to the skin (be it bumping against something or hitting yourself with a hammer). The raised area of a bump or bruise results from blood leaking from these injured blood vessels into the tissues as well as from the body's response to the injury. A purplish, flat bruise that occurs when blood leaks out into the top layers of skin is referred to as an ecchymosis.

COPD: Chronic obstructive pulmonary disease. Any disorder that persistently obstructs bronchial airflow. COPD mainly involves two related diseases -- chronic bronchitis and emphysema. Both cause chronic obstruction of air flowing through the airways and in and out of the lungs. The obstruction is generally permanent and progresses (becomes worse) over time.
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Coronary arteries: The vessels that supply the heart muscle with blood rich in oxygen. They are called the coronary arteries because they encircle the heart in the manner of a crown. The word "coronary" comes from the Latin "corona" and Greek "koron" meaning crown. Like other arteries, the coronaries may be subject to arteriosclerosis (hardening of the arteries). There are a number of coronary arteries. Those most often bypassed today include the right coronary artery, the posterior descending coronary artery, the left main coronary artery, the left anterior descending coronary artery and the left circumflex coronary artery. Plaques obstructing the coronary arteries may also be treated by balloon angioplasty, stents, and other techniques.

Coronary artery disease: A major cause of illness and death, coronary artery disease (CAD) begins when hard cholesterol substances (plaques) are deposited within a coronary artery.
See the entire definition of Coronary artery disease

Diagnosis: 1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV.
See the entire definition of Diagnosis

Dizziness: Painless head discomfort with many possible causes including disturbances of vision, the brain, balance (vestibular) system of the inner ear, and gastrointestinal system. Dizziness is a medically indistinct term which laypersons use to describe a variety of conditions ranging from lightheadedness, unsteadiness to vertigo.
See the entire definition of Dizziness

ECG: Abbreviation for electrocardiogram or EKG. The K is from "kardio" (in German).

Echocardiography: Echocardiography is a diagnostic test which uses ultrasound waves to make images of the heart chambers, valves and surrounding structures. It can measure cardiac output and is a sensitive test for inflammation around the heart (pericarditis). It can also be used to detect abnormal anatomy or infections of the heart valves.

ECST: ECST stands for the exercise cardiac stress test, the most widely used cardiac (heart) screening test.
See the entire definition of ECST

Ejection fraction: The portion of blood that is pumped out of a filled ventricle as a result of a heartbeat.
See the entire definition of Ejection fraction

Electrocardiogram: A recording of the electrical activity of the heart. An electrocardiogram is a simple, non-invasive procedure. Electrodes are placed on the skin of the chest and connected in a specific order to a machine that, when turned on, measures electrical activity all overaround the heart. Output is usually in the form of a long scroll of paper displaying a printed graph of activity. Newer models output the data directly to a computer and screen, although a print-out may still be made.
See the entire definition of Electrocardiogram

Electrolyte: An electrolyte is a substance that will dissociate into ions in solution and acquire the capacity to conduct electricity. The electrolytes include sodium, potassium, chloride, calcium and phosphate. Informally, called lytes. (The clue to the word electrolyte is in the lyte which comes from the Greek lytos meaning that may be dissolved.)

Electrophysiology: The biomedical field dealing with the study of electric activity in the body. Electrophysiology includes the study of the production of electrical activity and the effects of that electrical activity on the body. See, for example: Electrophysiologic retinal testing ; and Electrophysiologic study of the heart.

Emphysema: 1) A lung condition featuring an abnormal accumulation of air in the lung's many tiny air sacs, a tissue called alveoli. As air continues to collect in these sacs, they become enlarged, and may break, or be damaged and form scar tissue. Emphysema is strongly associated with smoking cigarettes, a practice that causes lung irritation. It can also be associated with or worsened by repeated infection of the lungs, such as is seen in chronic bronchitis. The best response to the early warning signs of emphysema is prevention: stop smoking and get immediate treatment for incipient lung infections. Curing established emphysema is not yet possible. Because patients don't have an adequate amount of space in the lungs to breathe, they gasp for breath, and may not be able to obtain enough oxygen. Those with severe emphysema usually end up using an oxygen machine to breathe. In some cases, medication may be helpful to ease symptoms or to treat infection in already-damaged lungs.
See the entire definition of Emphysema

Enzymes: Proteins that act as a catalysts in mediating and speeding a specific chemical reaction.
See the entire definition of Enzymes

Exercise cardiac stress testing: The most widely used cardiac (heart) screening test. The patient exercises on a treadmill according to a standardized protocol, with progressive increases in the speed and elevation of the treadmill (typically changing at three-minute intervals). During the exercise cardiac stress testing (ECST), the patient's electrocardiogram (EKG), heart rate, heart rhythm, and blood pressure are continuously monitored.
See the entire definition of Exercise cardiac stress testing

Fibrillation: In matters of the heart (cardiology), fibrillation is incoordinate twitching of the heart muscle fibers.
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Flutter: Flutter is a rapid vibration or pulsation. The difference between flutter and fibrillation is that flutter is well organized while fibrillation is not.
See the entire definition of Flutter

Heart: The muscle that pumps blood received from veins into arteries throughout the body. It is positioned in the chest behind the sternum (breastbone; in front of the trachea, esophagus, and aorta; and above the diaphragm muscle that separates the chest and abdominal cavities. The normal heart is about the size of a closed fist, and weighs about 10.5 ounces. It is cone-shaped, with the point of the cone pointing down to the left. Two-thirds of the heart lies in the left side of the chest with the balance in the right chest.
See the entire definition of Heart

Heart attack: The death of heart muscle due to the loss of blood supply. The loss of blood supply is usually caused by a complete blockage of a coronary artery, one of the arteries that supplies blood to the heart muscle. Death of the heart muscle, in turn, causes chest pain and electrical instability of the heart muscle tissue.
See the entire definition of Heart attack

Heart disease: Any disorder that affects the heart. Sometimes the term "heart disease" is used narrowly and incorrectly as a synonym for coronary artery disease. Heart disease is synonymous with cardiac disease but not with cardiovascular disease which is any disease of the heart or blood vessels. Among the many types of heart disease, see, for example: Angina; Arrhythmia; Congenital heart disease; Coronary artery disease (CAD); Dilated cardiomyopathy; Heart attack (myocardial infarction); Heart failure; Hypertrophic cardiomyopathy; Mitral regurgitation; Mitral valve prolapse; and Pulmonary stenosis.

Heart failure: Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart.
See the entire definition of Heart failure

Heart muscle: A type of muscle with unique features only found in the heart. The heart muscle, or cardiac muscle, is medically called the myocardium ("myo-" being the prefix denoting muscle).

Heart rate: The number of heart beats per unit time, usually per minute. The heart rate is based on the number of contractions of the ventricles (the lower chambers of the heart). The heart rate may be too fast (tachycardia) or too slow (bradycardia). The pulse is bulge of an artery from the wave of blood coursing through the blood vessel as a result of the heart beat. The pulse is often taken at the wrist to estimate the heart rate.

Heart valves: There are four heart valves. All are one-way valves. Blood entering the heart first passes through the tricuspid valve and then the pulmonary valve. After returning from the lungs, the blood passes through the mitral (bicuspid) valve and exits via the aortic valve.

Heart ventricle: One of the two lower chambers of the heart.
See the entire definition of Heart ventricle

High blood pressure: Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90.
See the entire definition of High blood pressure

Holter monitor: A type of portable heart monitor. The Holter monitor is a small portable electrocardiogram (ECG). The device is worn in a pouch around the neck or waist. It keeps a record of the heart rhythm, typically over a 24-hour period, while the patient keeps a diary recording their activities and any symptoms they may feel. The ECG recording is then correlated with the person's record of their activities and symptoms. The Holter monitor is useful for identifying disturbances which are sporadic and which are not readily identified with the usual resting electrocardiogram test.
See the entire definition of Holter monitor

Hypertrophy: Enlargement or overgrowth of an organ or part of the body due to the increased size of the constituent cells. Hypertrophy occurs in the biceps and heart because of increased work. Cardiac hypertrophy is recognizable microscopically by the increased size of the cells. The term hypertrophy is applied to the enlargement of the uterus during pregnancy. The term benign prostatic hypertrophy is a misnomer because the increased size of the prostate is due to hyperplasia, an increase in the number of cells.

Hypokalemia: Low blood potassium.
See the entire definition of Hypokalemia

Hypomagnesemia: Too little magnesium. Magnesium deficiency can occur due to inadequate intake or impaired intestinal absorption of magnesium. Low magnesium (hypomagnesemia) is often associated with low calcium (hypocalcemia) and low potassium (hypokalemia). Deficiency of magnesium causes increased irritability of the nervous system with tetany (spasms of the hands and feet, muscular twitching and cramps, spasm of the larynx, etc.). According to the National Academy of Sciences, the Recommended Dietary Allowances of magnesium are 420 milligrams per day for men and 320 milligrams per day for women. The upper limit of magnesium as supplements is 350 milligrams daily, in addition to the magnesium from food and water.

Hypoxia: A subnormal concentration of oxygen. By contrast with normoxia (normal oxygen) and anoxia (the absence or near absence of oxygen). From hyp- (below) + -ox- (oxygen) + -ia.

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Inflammation: A basic way in which the body reacts to infection, irritation or other injury, the key feature being redness, warmth, swelling and pain. Inflammation is now recognized as a type of nonspecific immune response.
See the entire definition of Inflammation

Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.

Left ventricle: The left lower chamber of the heart that receives blood from the left atrium and pumps it out under high pressure through the aorta to the body.

Low blood pressure: Any blood pressure that is below the normal expected for an individual in a given environment. Low blood pressure is also referred to as hypotension.
See the entire definition of Low blood pressure

Lungs: The lungs are a pair of breathing organs located with the chest which remove carbon dioxide from and bring oxygen to the blood. There is a right and left lung.

Magnesium: A mineral involved in many processes in the body including nerve signaling, the building of healthy bones, and normal muscle contraction. About 350 enzymes are known to depend on magnesium.
See the entire definition of Magnesium

Marker: A piece of DNA that lies on a chromosome so close to a gene that the marker and the gene are inherited together. A marker is thus an identifiable heritable spot on a chromosome. A marker can be an expressed region of DNA (a gene) or a segment of DNA with no known coding function. All that matters is that the marker can be detected and trailed.
See the entire definition of Marker

Medical history: 1. In clinical medicine, the patient's past and present which may contain clues bearing on their health past, present, and future. The medical history, being an account of all medical events and problems a person has experienced, including psychiatric illness, is especially helpful when a differential diagnosis is needed.
2. The history of medicine.

Mitral valve: A valve in the heart situated between the left atrium and the left ventricle that permits blood to flow from the left atrium into the left ventricle but not in the reverse direction.
See the entire definition of Mitral valve

Mitral valve prolapse: Drooping down or abnormal bulging of the mitral valve's cusps backward into the atrium during the contraction of the heart. Mitral valve prolapse is often an asymptomatic condition but it may be marked by mitral regurgitation with symptoms (as chest pain, fatigue, dizziness, dyspnea, or palpitations) with a tendency in some cases to endocarditis or ventricular tachycardia.
See the entire definition of Mitral valve prolapse

Muscle: Muscle is the tissue of the body which primarily functions as a source of power. There are three types of muscle in the body. Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." Heart muscle is called "cardiac muscle." Muscle that is in the walls of arteries and bowel is called "smooth muscle."

Myocarditis: Inflammation of the myocardium, the heart muscle.
See the entire definition of Myocarditis

Nasal: Having to do with the nose. Nasal drops are intended for the nose, not (for example) the eyes. The word "nasal" came from the Latin "nasus" meaning the nose or snout.

Neck: The part of the body joining the head to the shoulders. Also, any narrow or constricted part of a bone or organ that joins its parts as, for example, the neck of the femur bone.

Node: Literally a knot, a node is a collection of tissue. For example a lymph node, is a collection of lymphoid tissue. A nodule is a small node, a little collection of tissue.

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Oxygen: A colorless, odorless and tasteless gas that makes up about 20% of the air we breathe (and at least half the weight of the entire solid crust of the earth) and which combines with most of the other elements to form oxides. Oxygen is essential to human, animal and plant life.
See the entire definition of Oxygen

Oxygenation: The addition of oxygen to any system, including the human body. Oxygenation may also refer to the process of treating a patient with oxygen, or of combining a medication or other substance with oxygen.
See the entire definition of Oxygenation

Pacemaker: A system that sends electrical impulses to the heart in order to set the heart rhythm. The pacemaker can be the normal "natural" pacemaker of the heart or it can be an electronic device.
See the entire definition of Pacemaker

Palpitations: Unpleasant sensations of irregular and/or forceful beating of the heart. In some patients with palpitations, no heart disease or abnormal heart rhythms can be found. In others, palpitations result from abnormal heart rhythms (arrhythmias). Arrhythmias refer to heartbeats that are too slow, too rapid, irregular, or too early.

Pericardium: The conical sac of fibrous tissue that surrounds the heart and the roots of the great blood vessels. The pericardium's outer coat (the parietal pericardium) is tough and thickened, loosely cloaks the heart, and is attached to the central part of the diaphragm and the back of the breastbone. Its inner coat (the visceral pericardium or epicardium) is double, with one layer closely adherent to the heart and the other lining the inner surface of the outer coat. The intervening space between these layers is filled with pericardial fluid. This small amount of fluid acts as a lubricant to allow normal heart movement within the chest.
See the entire definition of Pericardium

Potassium: The major positive ion (cation) found inside of cells. The chemical notation for potassium is K+.
See the entire definition of Potassium

Premature ventricular contraction: PVC. A contraction of the lower chambers of the heart, the ventricles, which occur earlier than usual, because of abnormal electrical activity of the ventricles. The premature contraction is followed by a pause, as the heart electrical system "resets" itself and the contraction following the pause is usually more forceful than normal. These more forceful contractions are frequently perceived as palpitations. Also called an extrasystole.

Preoperative: Before surgery. As opposed to postoperative, after surgery.

Prognosis: 1. The expected course of a disease.
2. The patient's chance of recovery.
The prognosis predicts the outcome of a disease and therefore the future for the patient. His prognosis is grim, for example, while hers is good.
See the entire definition of Prognosis

Progressive: Increasing in scope or severity. Advancing. Going forward. In medicine, a disease that is progressive is going from bad to worse.

Proteins: Large molecules composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein.
See the entire definition of Proteins

PTCA: Percutaneous transluminal coronary angioplasty. A procedure with a balloon-tipped catheter to enlarge a narrowing in a coronary artery. Often just called angioplasty.

Pulmonary: Having to do with the lungs. (The word comes from the Latin pulmo for lung).

Pulse: The rhythmic contraction and expansion of an artery due to the surge of blood from the beat of the heart. The pulse is most often measured by feeling the arteries of the wrist. There is also a pulse, although far weaker, in veins.

Right atrium: The right upper chamber of the heart. The right atrium receives deoxygenated blood from the body through the vena cava and pumps it into the right ventricle which then sends it to the lungs to be oxygenated.

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Right ventricle: The lower right chamber of the heart that receives deoxygenated blood from the right atrium and pumps it under low pressure into the lungs via the pulmonary artery.
See the entire definition of Right ventricle

SA node: The SA node (SA stands for sinoatrial) is one of the major elements in the cardiac conduction system, the system that controls the heart rate. This stunningly designed system generates electrical impulses and conducts them throughout the muscle of the heart, stimulating the heart to contract and pump blood.
See the entire definition of SA node

Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems.
See the entire definition of Stress

Stress echocardiography: A supplement to the routine exercise cardiac stress test. During stress echocardiography, the sound waves of ultrasound are used to produce images of the heart at rest and at the peak of exercise.
See the entire definition of Stress echocardiography

Syncope: Partial or complete loss of consciousness with interruption of awareness of oneself and ones surroundings. When the loss of consciousness is temporary and there is spontaneous recovery, it is referred to as syncope or, in nonmedical quarters, fainting. Syncope accounts for one in every 30 visits to an emergency room. It is pronounced sin-ko-pea.
See the entire definition of Syncope

Tachycardia: A rapid heart rate, usually defined as greater than 100 beats per minute. The tachycardias include sinus tachycardia, paroxysmal atrial tachycardia (PAT), and ventricular tachycardia.
See the entire definition of Tachycardia

Thyroid: 1. The thyroid gland. Also, pertaining to the thyroid gland. 2. A preparation of the thyroid gland used to treat hypothyroidism. 3. Shaped like a shield. (The thyroid gland was so-named by Thomas Wharton in 1656 because it was shaped like an ancient Greek shield.)
See the entire definition of Thyroid

Toxicity: The degree to which a substance can harm humans or animals.
See the entire definition of Toxicity

Treadmill: A machine with a moving strip on which one walks without moving forward. A treadmill was originally a wide wheel turned by the weight of people climbing on steps around its edge, used in the past to provide power for machines or as a punishment in prisons.
See the entire definition of Treadmill

Tricyclic antidepressants (TCAs): One of a class of medications used to treat depression. The tricyclic antidepressants (TCAs) are also used for some forms of anxiety, fibromyalgia, and the control of chronic pain.
See the entire definition of Tricyclic antidepressants

Ultrasound: High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. Ultrasound is often used to examine a fetus during pregnancy. There is no convincing evidence for any danger from ultrasound during pregnancy.

Ventricle: A chamber of an organ. For example, the four connected cavities (hollow spaces) in the central portion of the brain and the lower two chambers of the heart are called ventricles.

Ventricles: 1, The right ventricle and the left ventricle, the lower two chambers of the heart. 2. Two or more of the four connected spaces within the central portion of the brain.

Ventricular: Pertaining to the ventricles, the lower chambers of the heart, as in ventricular fibrillation and ventricular septal defect.

Ventricular arrhythmias: Abnormal rapid heart rhythms (arrhythmias) that originate in the lower chambers of the heart (the ventricles). Ventricular arrhythmias include ventricular tachycardia and ventricular fibrillation. Both are life threatening arrhythmias most commonly associated with heart attacks or scarring of the heart muscle from previous heart attack.

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Ventricular fibrillation: An abnormal irregular heart rhythm whereby there are very rapid uncoordinated fluttering contractions of the lower chambers (ventricles) of the heart. Ventricular fibrillation disrupts the synchrony between the heartbeat and the pulse beat. Ventricular fibrillation is most commonly associated with heart attacks or scarring of the heart muscle from previous heart attack. It is life-threatening.

Ventricular tachycardia: An abnormally rapid heart rhythm that originates from a ventricle, one of the lower chambers of the heart. Although the beat is regular, ventricular tachycardia is life-threatening because it can lead to a dreaded condition, ventricular fibrillation.
See the entire definition of Ventricular tachycardia

Weight loss: Weight loss is a decrease in body weight resulting from either voluntary (diet, exercise) or involuntary (illness) circumstances. Most instances of weight loss arise due to the loss of body fat, but in cases of extreme or severe weight loss, protein and other substances in the body can also be depleted. Examples of involuntary weight loss include the weight loss associated with cancer, malabsorption (such as from chronic diarrheal illnesses ), and chronic inflammation (such as with rheumatoid arthritis).

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      • Potassium is an essential electrolyte necessary for cell function. Low potassium (hypokalemia) may be caused by diarrhea, vomiting, ileostomy, colon polyps, laxative use, diuretics, elevated corticosteroid levels, renal artery stenosis, and renal tubular acidosis, or other medications. Symptoms of low potassium include weakness, aches, and cramps of the muscles. Treatment is dependant upon the cause of the low potassium (hypokalemia).
    • Atrial Fibrillation
      • Atrial fibrillation is an abnormality in the heart rhythm which involves irregular and often rapid beating of the heart.
    • Emphysema
      • Emphysema is a progressive disease of the lungs. The primary cause of emphysema is smoking. Alpha 1-antitrypsin deficiency is a rare disorder that has a genetic predisposition to emphysema. Aging, IV drug use, immune deficiencies, and connect tissue illnesses are also risk factors for emphysema. Emphysema is a subtype of COPD (chronic obstructive pulmonary disease, COLD). Symptoms include shortness of breath and wheezing. Management of symptoms may be achieved with medications, quitting smoking, pulmonary rehabilitation, or surgery.
    • Abnormal Heart Rhythms (Heart Rhythm Disorders)
      • Heart rhythm disorders vary from minor palpitations, premature atrial contractions (PACs), premature ventricular contractions (PVCs), sinus tachycardia, and sinus brachycardia, to abnormal heart rhythms such as tachycardia, ventricular fibrillation, ventricular flutter, atrial fibrillation, atrial flutter, paroxysmal supraventricular tachycardia (PSVT), Wolf-White-Parkinson syndrome, brachycardia, or heart blocks. Treatment is dependant upon the type of heart rhythm disorder.
    • Heart Disease
      • Heart disease (coronary artery disease) is caused by a buildup of cholesterol deposits in the coronary arteries. Risk factors for heart disease include smoking, high blood pressure, heredity, diabetes, peripheral artery disease, and obesity. Symptoms include chest pain and shortness of breath. There are a variety of tests used to diagnose coronary artery disease. Treatment includes life-style changes, medications, procedures, or surgery.
    • Heart Valve Disease
      • Heart valve disease occurs when the heart valves do not work the way they should. Symptoms of valve disease include shortness of breath, weakness or dizziness, discomfort in your chest, palpitations, swelling of your ankles, feet or abdomen, and rapid weight gain.
    • Myocarditis
      • Myocarditis is an inflammation of the heart muscle and can be caused by a variety of infections, conditions, and viruses. Symptoms of myocarditis include chest pain, shortness of breath, fatigue, and fluid accumulation in the lungs. Treatment mainly involves preventing heart failure with medication and diet, as well as monitoring for heart rhythm abnormalities.
    • Sudden Cardiac Arrest
      • Sudden cardiac arrest is an unexpected, sudden death caused by sudden cardiac arrest (loss of heart function). Causes and risk factors of sudden cardiac arrest include (not inclusive): abnormal heart rhythms (arrhythmias), previous heart attack, coronary artery disease, smoking, high cholesterol, Wolff-Parkinson-White Syndrome, ventricular tachycardia or ventricular fibrillation after a heart attack, congenital heart defects, history of fainting, and heart failure, obesity, diabetes, and drug abuse. Treatment of sudden cardiac arrest is an emergency, and action must be taken immediately.
    • Heart Failure
      • Heart failure is caused by many conditions including coronary artery disease, heart attack, cardiomyopathy, and conditions that overwork the heart. Symptoms of heart failure include congested lungs, fluid and water retention, dizziness, fatigue and weakness, and rapid or irregular heartbeats.
    • How the Heart Works
      • The heart is a very important organ in the body. It is responsible for continuously pumping oxygen and nutrient-rich blood throughout your body to sustain life. It is a fist-sized muscle that beats (expands and contracts) 100,000 times per day, pumping a total of five or six quarts of blood each minute, or about 2,000 gallons per day.
    • Emphysema, Chronic Bronchitis, and Colds
      • If you have a COPD such as emphysema, avoiding chronic bronchitis and colds is important to avoid a more severe respiratory infection such as pneumonia. Avoiding cigarette smoking, practice good hygeine, stay away from crowds, and alerting your healthcare provider if you have a sinus infection or cold or cough that becomes worse. Treatment options depend upon the severity of the emphysema, bronchitis, or cold combination.
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Premature Ventricular Contractions (PVCs)

Intoduction to How The Heart Works

Your heart is an amazing organ. It continuously pumps oxygen and nutrient-rich blood throughout your body to sustain life. This fist-sized powerhouse beats (expands and contracts) 100,000 times per day, pumping five or six quarts of blood each minute, or about 2,000 gallons per day.

How Does Blood Travel Through the Heart?

As the heart beats, it pumps blood through a system of blood vessels, called the circulatory system. The vessels are elastic, muscular tubes that carry blood to every part of the body.

Blood is essential. In addition to carrying fresh oxygen from the lungs and nutrients to your body's tissues, it also takes the body's waste products, including carbon dioxide, away from the tissues. This is necessary to sustain life and promote the health of all the body's tissues.

There are three main types of blood vessels:

  • Arteries. They begin with the aorta, the l...

Read the How the Heart Works article »







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