ElectrocardiographyElectrocardiography is the process of producing an electrocardiogram (ECG or EKG ), a recording of the heart's electrical activity through repeated cardiac cycles. 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).
ArrhythmiaArrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults – is called tachycardia, and a resting heart rate that is too slow – below 60 beats per minute – is called bradycardia. Some types of arrhythmias have no symptoms. Symptoms, when present, may include palpitations or feeling a pause between heartbeats.
Athletic heart syndromeAthletic heart syndrome (AHS) is a non-pathological condition commonly seen in sports medicine in which the human heart is enlarged, and the resting heart rate is lower than normal. The athlete's heart is associated with physiological cardiac remodeling as a consequence of repetitive cardiac loading. Athlete's heart is common in athletes who routinely exercise more than an hour a day, and occurs primarily in endurance athletes, though it can occasionally arise in heavy weight trainers.
Signal-averaged electrocardiogramSignal-averaged electrocardiography (SAECG) is a special electrocardiographic technique, in which multiple electric signals from the heart are averaged to remove interference and reveal small variations in the QRS complex, usually the so-called "late potentials". These may represent a predisposition towards potentially dangerous ventricular tachyarrhythmias. A resting electrocardiogram (ECG) is recorded in the supine position using an ECG machine equipped with SAECG software; this can be done by a physician, nurse, or medical technician.
Heart rateHeart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions of the heart per minute (beats per minute, or bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excrete carbon dioxide, but is also modulated by numerous factors, including (but not limited to) genetics, physical fitness, stress or psychological status, diet, drugs, hormonal status, environment, and disease/illness as well as the interaction between and among these factors.
Holter monitorIn medicine, a Holter monitor (often simply Holter) is a type of ambulatory electrocardiography device, a portable device for cardiac monitoring (the monitoring of the electrical activity of the cardiovascular system) for at least 24 hours. The Holter's most common use is for monitoring ECG heart activity (electrocardiography or ECG). Its extended recording period is sometimes useful for observing occasional cardiac arrhythmias which would be difficult to identify in a shorter period.
TelehealthTelehealth is the distribution of health-related services and information via electronic information and telecommunication technologies. It allows long-distance patient and clinician contact, care, advice, reminders, education, intervention, monitoring, and remote admissions. Telemedicine is sometimes used as a synonym, or is used in a more limited sense to describe remote clinical services, such as diagnosis and monitoring.
Atrioventricular blockAtrioventricular block (AV block) is a type of heart block that occurs when the electrical signal traveling from the atria, or the upper chambers of the heart, to ventricles, or the lower chambers of the heart, is impaired. Normally, the sinoatrial node (SA node) produces an electrical signal to control the heart rate. The signal travels from the SA node to the ventricles through the atrioventricular node (AV node). In an AV block, this electrical signal is either delayed or completely blocked.
BradycardiaBradycardia (also sinus bradycardia) is a slow resting heart rate, commonly under 60 beats per minute (BPM) as determined by an electrocardiogram. It is considered to be a normal heart rate during sleep, in young and healthy or elderly adults, and in athletes. In some people, bradycardia below 60 BPM may be associated with fatigue, weakness, dizziness, sweating, and fainting. The term "relative bradycardia" is used to refer to a heart rate slower than an individual's typical resting heart rate.
Atrial tachycardiaAtrial tachycardia is a type of heart rhythm problem in which the heart's electrical impulse comes from an ectopic pacemaker (that is, an abnormally located cardiac pacemaker) in the upper chambers (atria) of the heart, rather than from the sinoatrial node, the normal origin of the heart's electrical activity. As with any other form of tachycardia (rapid heart beat), the underlying mechanism can be either the rapid discharge of an abnormal focus, the presence of a ring of cardiac tissue that gives rise to a circle movement (reentry), or a triggered rapid rhythm due to other pathological circumstances (as would be the case with some drug toxicities, such as digoxin toxicity).
Cardiac conduction systemThe cardiac conduction system (CCS) (also called the electrical conduction system of the heart) transmits the signals generated by the sinoatrial node – the heart's pacemaker, to cause the heart muscle to contract, and pump blood through the body's circulatory system. The pacemaking signal travels through the right atrium to the atrioventricular node, along the bundle of His, and through the bundle branches to Purkinje fibers in the walls of the ventricles. The Purkinje fibers transmit the signals more rapidly to stimulate contraction of the ventricles.
Heart soundsHeart sounds are the noises generated by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. In cardiac auscultation, an examiner may use a stethoscope to listen for these unique and distinct sounds that provide important auditory data regarding the condition of the heart. In healthy adults, there are two normal heart sounds, often described as a lub and a dub that occur in sequence with each heartbeat.
Ventricular tachycardiaVentricular tachycardia (V-tach or VT) is a fast heart rate arising from the lower chambers of the heart. Although a few seconds of VT may not result in permanent problems, longer periods are dangerous; and multiple episodes over a short period of time are referred to as an electrical storm. Short periods may occur without symptoms, or present with lightheadedness, palpitations, or chest pain. Ventricular tachycardia may result in ventricular fibrillation (VF) and turn into cardiac arrest.
Fourth heart soundThe fourth heart sound or S4 is an extra heart sound that occurs during late diastole, immediately before the normal two "lub-dub" heart sounds (S1 and S2). It occurs just after atrial contraction and immediately before the systolic S1 and is caused by the atria contracting forcefully in an effort to overcome an abnormally stiff or hypertrophic ventricle. This produces a rhythm classically compared to the cadence of the word "Tennessee." One can also use the phrase "A-stiff-wall" to help with the cadence (a S4, stiff S1, wall S2), as well as the pathology of the S4 sound.
Computational physicsComputational physics is the study and implementation of numerical analysis to solve problems in physics. Historically, computational physics was the first application of modern computers in science, and is now a subset of computational science. It is sometimes regarded as a subdiscipline (or offshoot) of theoretical physics, but others consider it an intermediate branch between theoretical and experimental physics - an area of study which supplements both theory and experiment.
Monitoring (medicine)In medicine, monitoring is the observation of a disease, condition or one or several medical parameters over time. It can be performed by continuously measuring certain parameters by using a medical monitor (for example, by continuously measuring vital signs by a bedside monitor), and/or by repeatedly performing medical tests (such as blood glucose monitoring with a glucose meter in people with diabetes mellitus). Transmitting data from a monitor to a distant monitoring station is known as telemetry or biotelemetry.
Computational scienceComputational science, also known as scientific computing, technical computing or scientific computation (SC), is a division of science that uses advanced computing capabilities to understand and solve complex physical problems. This includes Algorithms (numerical and non-numerical): mathematical models, computational models, and computer simulations developed to solve sciences (e.
StethoscopeThe stethoscope is a medical device for auscultation, or listening to internal sounds of an animal or human body. It typically has a small disc-shaped resonator that is placed against the skin, with either one or two tubes connected to two earpieces. A stethoscope can be used to listen to the sounds made by the heart, lungs or intestines, as well as blood flow in arteries and veins. In combination with a manual sphygmomanometer, it is commonly used when measuring blood pressure.
