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Cardiology. A premature ventricular contraction (PVC) is a common event where the heartbeat is initiated by Purkinje fibers in the ventricles rather than by the sinoatrial node. PVCs may cause no symptoms or may be perceived as a "skipped beat" or felt as palpitations in the chest. PVCs do not usually pose any danger.
Cardiology, electrophysiology. Premature atrial contraction (PAC), also known as atrial premature complexes (APC) or atrial premature beats (APB), are a common cardiac dysrhythmia characterized by premature heartbeats originating in the atria. While the sinoatrial node typically regulates the heartbeat during normal sinus rhythm, PACs occur ...
Cardiology. Ectopic beat is a disturbance of the cardiac rhythm frequently related to the electrical conduction system of the heart, in which beats arise from fibers or group of fibers outside the region in the heart muscle ordinarily responsible for impulse formation (i.e., the sinoatrial node). An ectopic beat can be further classified as ...
Bigeminy. Bigeminy is a cardiac arrhythmia in which there is a single ectopic beat, or irregular heartbeat, following each regular heartbeat. Most often this is due to ectopic beats occurring so frequently that there is one after each sinus beat, or normal heartbeat. The two beats are figuratively similar to two twins (hence bi- + gemini).
A fusion beat occurs when electrical impulses from different sources act upon the same region of the heart at the same time. [1] If it acts upon the ventricular chambers it is called a ventricular fusion beat, whereas colliding currents in the atrial chambers produce atrial fusion beats. Ventricular fusion beats can occur when the heart's ...
Second-degree atrioventricular block (AV block) is a disease of the electrical conduction system of the heart. It is a conduction block between the atria and ventricles. The presence of second-degree AV block is diagnosed when one or more (but not all) of the atrial impulses fail to conduct to the ventricles due to impaired conduction.
Polyvinyl chloride (alternatively: poly (vinyl chloride), [ 6 ][ 7 ] colloquial: vinyl[ 8 ] or polyvinyl; abbreviated: PVC[ 8 ]) is the world's third-most widely produced synthetic polymer of plastic (after polyethylene and polypropylene). About 40 million tons of PVC are produced each year. [ 9 ]
Concealed conduction is tissue stimulation without direct effect, but leading to a change in conduction characteristics. [1] The term "concealed" is in reference to that the conduction is not observable by electrocardiogram. A common example would be an interpolated PVC (a type of premature ventricular contraction) during normal sinus rhythm ...