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QT-interval
The QT interval is a measurement made on an electrocardiogram used to assess some of the electrical properties of the heart. It is calculated as the time from the start of the Q wave to the end of the T wave, and approximates to the time taken from when the cardiac ventricles start to contract to when they finish relaxing. An abnormally long or abnormally short QT interval is associated with an increased risk of developing abnormal heart rhythms and sudden cardiac death. Abnormalities in the QT interval can be caused by genetic conditions such as long QT syndrome, by certain medications such as sotalol or pitolisant, by disturbances in the concentrations of certain salts within the blood such as hypokalaemia, or by hormonal imbalances such as hypothyroidism. Measurement The QT interval is most commonly measured in lead II for evaluation of serial ECGs, with leads I and V5 being comparable alternatives to lead II. Leads III, aVL and V1 are generally avoided for measurement o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrocardiography
Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the heart using electrodes placed on the skin. These electrodes detect the small electrical changes that are a consequence of cardiac muscle depolarization followed by repolarization during each cardiac cycle (heartbeat). Changes in the normal ECG pattern occur in numerous cardiac abnormalities, including cardiac rhythm disturbances (such as atrial fibrillation and ventricular tachycardia), inadequate coronary artery blood flow (such as myocardial ischemia and myocardial infarction), and electrolyte disturbances (such as hypokalemia and hyperkalemia). Traditionally, "ECG" usually means a 12-lead ECG taken while lying down as discussed below. However, other devices can record the electrical activity of the heart such as a Holter monitor but also s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiologist
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathological state'' refers to abnormal conditions, including human diseases. The Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Foundations Cells Although there are difference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensorineural Hearing Loss
Sensorineural hearing loss (SNHL) is a type of hearing loss in which the root cause lies in the inner ear or sensory organ (cochlea and associated structures) or the vestibulocochlear nerve (cranial nerve VIII). SNHL accounts for about 90% of reported hearing loss . SNHL is usually permanent and can be mild, moderate, severe, profound, or total. Various other descriptors can be used depending on the shape of the audiogram, such as high frequency, low frequency, U-shaped, notched, peaked, or flat. ''Sensory'' hearing loss often occurs as a consequence of damaged or deficient cochlear hair cells. Hair cells may be abnormal at birth or damaged during the lifetime of an individual. There are both external causes of damage, including infection, and ototoxic drugs, as well as intrinsic causes, including genetic mutations. A common cause or exacerbating factor in SNHL is prolonged exposure to environmental noise, or noise-induced hearing loss. Exposure to a single very loud noise such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes ( autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance such as incomplete d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NOS1AP
Nitric oxide synthase 1 adaptor protein (NOS1AP) also known as carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase protein (CAPON) is a protein that in humans is encoded by the ''NOS1AP'' gene. This gene encodes a cytosolic protein that binds to the signaling molecule, neuronal nitric oxide synthase (nNOS). This protein has a C-terminal PDZ-binding domain that mediates interactions with nNOS and an N-terminal phosphotyrosine binding (PTB) domain that binds to the small monomeric G protein, Dexras1. Studies of the related mouse and rat proteins have shown that this protein functions as an adapter protein linking nNOS to specific targets, such as Dexras1 and the synapsins. NOS1AP polymorphisms has been associated with the QT interval length. Interactions NOS1AP has been shown to interact with: * LRP1, * LRP2, * NOS1, * RASD1 Dexamethasone-induced Ras-related protein 1 (RASD1) is a protein that in humans is encoded by the ''RASD1'' gene on chromosome 17. It is ubi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short QT Syndrome
Short QT syndrome (SQT) is a very rare genetic disease of the electrical system of the heart, and is associated with an increased risk of abnormal heart rhythms and sudden cardiac death. The syndrome gets its name from a characteristic feature seen on an electrocardiogram (ECG) – a shortening of the QT interval. It is caused by mutations in genes encoding ion channels that shorten the cardiac action potential, and appears to be inherited in an autosomal dominant pattern. The condition is diagnosed using a 12-lead ECG. Short QT syndrome can be treated using an implantable cardioverter-defibrillator or medications including quinidine. Short QT syndrome was first described in 2000, and the first genetic mutation associated with the condition was identified in 2004. Signs and symptoms Those affected by short QT syndrome (SQT) have an increased risk of developing abnormal heart rhythms. These abnormal heart rhythms often occur at a young age. They may take relatively ben ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QT Distribution
QT or Qt may refer to: Arts and media * QT (musician) (born 1988), pop singer * '' QT: QueerTelevision'', an LGBT newsmagazine which aired on Canada's CityTV in the 1990s * Quentin Tarantino (born 1963), American filmmaker * ''Question Time'' (TV programme), a topical debate BBC television programme in the UK Organizations * QuikTrip, a US convenience store chain * QT Inc., manufacturer of the Q-Ray ionized bracelet * QT Hotels & Resorts * The Qt Company Science and technology Medicine * QT interval, on an electrocardiogram ** Long QT syndrome, a rare heart condition ** Short QT syndrome, a very rare disease of the heart Other uses in science and technology * Qt (software), a cross-platform application framework * QuickTime, a multimedia technology from Apple Inc. * Quiet Trader, cargo versions of the BAe 146 jet * Quart (qt), a unit of volume equal to a quarter of a gallon Other uses * Quality time, time spent with loved ones which is in some way special * QT (New York City ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torsades De Pointes
''Torsades de pointes, torsade de pointes'' or ''torsades des pointes'' (TdP) (, , translated as "twisting of peaks") is a specific type of abnormal heart rhythm that can lead to sudden cardiac death. It is a polymorphic ventricular tachycardia that exhibits distinct characteristics on the electrocardiogram (ECG). It was described by French physician François Dessertenne in 1966. Prolongation of the QT interval can increase a person's risk of developing this abnormal heart rhythm, occurring in between 1% and 10% of patients who receive QT-prolonging antiarrhythmic drugs. Signs and symptoms Most episodes will revert spontaneously to a normal sinus rhythm. Symptoms and consequences include palpitations, dizziness, lightheadedness (during shorter episodes), fainting (during longer episodes), and sudden cardiac death. Causes Torsades occurs as both an inherited (linked to at least 17 genes) and as an acquired form caused most often by drugs and/or electrolyte disorders that ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sudden Cardiac Death
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possibly defibrillation are needed until further treatment can be provided. Cardiac arrest results in a rapid loss of consciousness, and breathing may be abnormal or absent. While cardiac arrest may be caused by heart attack or heart failure, these are not the same, and in 15 to 25% of cases, there is a non-cardiac cause. Some individuals may experience chest pain, shortness of breath, nausea, an elevated heart rate, and a light-headed feeling immediately before entering cardiac arrest. The most common cause of cardiac arrest is an underlying heart problem like coronary artery disease that decreases the amount of oxygenated blood supplying the heart muscle. This, in turn, damages the structure of the muscle, which can alter its function. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QT Interval Corrected For Heart Rate
QT or Qt may refer to: Arts and media * QT (musician) (born 1988), pop singer * '' QT: QueerTelevision'', an LGBT newsmagazine which aired on Canada's CityTV in the 1990s * Quentin Tarantino (born 1963), American filmmaker * ''Question Time'' (TV programme), a topical debate BBC television programme in the UK Organizations * QuikTrip, a US convenience store chain * QT Inc., manufacturer of the Q-Ray ionized bracelet * QT Hotels & Resorts * The Qt Company Science and technology Medicine * QT interval, on an electrocardiogram ** Long QT syndrome, a rare heart condition ** Short QT syndrome, a very rare disease of the heart Other uses in science and technology * Qt (software), a cross-platform application framework * QuickTime, a multimedia technology from Apple Inc. * Quiet Trader, cargo versions of the BAe 146 jet * Quart (qt), a unit of volume equal to a quarter of a gallon Other uses * Quality time, time spent with loved ones which is in some way special * QT (New York City ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrospective Study
A retrospective cohort study, also called a historic cohort study, is a longitudinal cohort study used in medical and psychological research. A cohort of individuals that share a common exposure factor is compared with another group of equivalent individuals not exposed to that factor, to determine the factor's influence on the incidence of a condition such as disease or death. Retrospective cohort studies have existed for approximately as long as prospective cohort studies. Design The retrospective cohort study compares groups of individuals who are alike in many ways but differ by a certain characteristic (for example, female nurses who smoke and ones who do not smoke) in terms of a particular outcome (such as lung cancer). Data on the relevant events for each individual (the form and time of exposure to a factor, the latent period, and the time of any subsequent occurrence of the outcome) are collected from existing records and can immediately be analyzed to determine the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verify Source
CONFIG.SYS is the primary configuration file for the DOS and OS/2 operating systems. It is a special ASCII text file that contains user-accessible setup or configuration directives evaluated by the operating system's DOS BIOS (typically residing in IBMBIO.COM or IO.SYS) during boot. CONFIG.SYS was introduced with DOS 2.0. Usage The directives in this file configure DOS for use with devices and applications in the system. The CONFIG.SYS directives also set up the memory managers in the system. After processing the CONFIG.SYS file, DOS proceeds to load and execute the command shell specified in the SHELL line of CONFIG.SYS, or COMMAND.COM if there is no such line. The command shell in turn is responsible for processing the AUTOEXEC.BAT file. CONFIG.SYS is composed mostly of name=value directives which look like variable assignments. In fact, these will either define some tunable parameters often resulting in reservation of memory, or load files, mostly device drivers and TSRs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
