Atrioventricular Nodal Re-entry Tachycardia: From 1 Different Sources
(AVNRT) *re-entry tachycardia arising from the presence of an abnormal electrical connection between atria and ventricles situated within the *atrioventricular node.
Abnormally fast heartbeat.... tachycardia
An unusually fast but regular beating of the HEART occurring for periods that may last several hours or days. In most people with this abnormality the heart rate is between 140 and 180 beats a minute; rarely, the rate may rise as high as 250–300 beats. The condition occurs when abnormal electrical impulses that arise in the upper chambers (atria) of the heart override the normal control centre – the sinoatrial node – for the heartbeat. Symptoms usually include breathlessness, palpitations, pain in the chest and fainting. An ELECTROCARDIOGRAM (ECG) is taken to help make the diagnosis. An acute episode can sometimes be stopped by VALSAVA’S MANOEUVRE or by drinking cold water. Anti-arrhythmic drugs (see ARRHYTHMIA) such as adenosine and digoxin are used to treat recurrent attacks. Occasionally, a severe attack may need to be treated with an electric shock to the heart: this is known as DEFIBRILLATION.... supraventricular tachycardia
A regular heart rate of 100 or more beats a minute, caused by increased electrical activity in the SINOATRIAL NODE (see also HEART). This level of tachycardia is normal during and just after exercise, and may also be caused by stress or anxiety. If tachycardia persists when the person is resting, it may be due to underlying disease such as thyrotoxicosis (see under THYROID GLAND, DISEASES OF) and investigation is advisable.... sinus tachycardia
A small knot of specialized muscle cells in the right atrium of the heart. Electrical impulses from the sinoatrial node pass through the atrioventricular node and along conducting fibres to the ventricles, causing them to contract.... atrioventricular node
A local or regional access point where older persons receive information, assessment of needs, care planning, referrals to health and social services and, in some systems, authorization of services for home care, community-based care or residential care facilities.... single point of entry
(AV bundle, bundle of His) a bundle of modified heart muscle fibres (Purkinje fibres) passing from the *atrioventricular node forward to the septum between the ventricles, where it divides into right and left bundles, one for each ventricle. The fibres transmit contraction waves from the atria, via the AV node, to the ventricles.... atrioventricular bundle
(AVRT) *re-entry tachycardia arising from the presence of an abnormal electrical connection between atria and ventricles situated outside the *atrioventricular node. See accessory pathway.... atrioventricular reciprocating tachycardia
a rapid heart rate due to a self-sustaining circulation of electrical impulses from the atria to the ventricles and back again. This re-entry circuit requires the presence of an abnormal second electrical conduction pathway in addition to the usual atrioventricular nodal connection route. The abnormal pathway may be located within the *atrioventricular node (causing *atrioventricular nodal re-entry tachycardia) or it may be an *accessory pathway situated outside the atrioventricular node (causing *atrioventricular reciprocating tachycardia). Medication is often effective and *radiofrequency ablation is usually curative.... re-entry tachycardia
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