arrhythmia

arrhythmia
—arrhythmic /euh ridh"mik, ay ridh"-/, arrhythmical, adj. —arrhythmically, adv.
/euh ridh"mee euh, ay ridh"-/, n. Pathol.
any disturbance in the rhythm of the heartbeat.
Also, arhythmia.
[1885-90; < NL < Gk arrhythmía. See A-6, RHYTHM, -IA]

* * *

Variation from the heartbeat's normal rate or rhythm, caused by problems in the heart's pacemaker or in nerves conducting its signals.

Occasional arrhythmias are normal. Tachycardia is a fast regular rhythm; bradycardia is a slow rhythm. Premature atrial or ventricular beats are extra contractions in normal rhythm. Ongoing arrhythmia in some heart diseases can reduce the heart's ability to supply the body with blood and can lead to heart failure. Severe arrhythmias can trigger atrial fibrillation or ventricular fibrillation. Arrhythmias are detected by electrocardiography and treated by electric shock (often with an implanted pacemaker) or by drugs such as quinidine and digitalis.

* * *

      variation from the normal rate or regularity of the heartbeat, usually resulting from irregularities within the conduction system of the heart. Arrhythmias occur in both normal and diseased hearts and have no medical significance in and of themselves, although they may endanger heart function when coupled with other cardiac abnormalities.

      Types of arrhythmias include tachycardia, which is a regular acceleration of the heart rate; bradycardia, a regular slowing of the heart rate; and premature atrial or ventricular beats, which are extra contractions within otherwise normal heart rhythm. While occasional irregularities are normal, prolonged or chronic arrhythmias associated with some forms of heart disease may reduce cardiac output, lowering blood pressure and affecting the perfusion of vital organs with blood, and can precipitate heart failure. Severe arrhythmias can trigger atrial fibrillation or ventricular fibrillation, in which the heart beats ineffectively at many times its normal rate.

      Arrhythmias reflect the failure of the sinoatrial node, the normal cardiac pacemaker, to maintain a regular heartbeat, usually because of defects in the various pathways by which electrical impulses are carried to different areas of the heart. Anatomical defects or disease can slow down or speed up the propagation of electrical impulses, causing them to arrive out of the normal rhythm, or can turn the impulses back on their path, short-circuiting the pacemaker. Many arrhythmias can be corrected through physical methods, such as artificial pacemakers (pacemaker), defibrillators, and radiofrequency ablation (the application of radiofrequency energy to the area of the heart that is causing the arrhythmia), or by drugs such as beta-blockers (beta-blocker) and calcium channel blockers.

* * *


Universalium. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • arrhythmia — [ə rith′mē ə] n. [ModL < Gr, lack of rhythm < a , without + rhythmos, measure] any irregularity in the rhythm of the heart s beating arrhythmic adj. arrhythmical arrhythmically adv …   English World dictionary

  • Arrhythmia — An abnormal heart rhythm. In an arrhythmia the heartbeats may be too slow, too rapid, too irregular, or too early. Rapid arrhythmias (greater than 100 beats per minute) are called tachycardias. Slow arrhythmias (slower than 60 beats per minute)… …   Medical dictionary

  • arrhythmia — Lack of normal ordered rhythm particularly in the case of the heart where arrhythmia can be a prelude to cardiac arrest …   Dictionary of molecular biology

  • arrhythmia — ar•rhyth•mi•a [[t]əˈrɪð mi ə, eɪˈrɪð [/t]] n. pat any disturbance in the rhythm of the heartbeat • Etymology: 1885–90; < Gk arrhythmía. See a VI, rhythm ar•rhyth′mic, ar•rhyth′mi•cal, adj. ar•rhyth′mi•cal•ly, adv …   From formal English to slang

  • arrhythmia — noun an abnormal rate of muscle contractions in the heart • Syn: ↑cardiac arrhythmia • Derivationally related forms: ↑arrhythmic • Hypernyms: ↑heart disease, ↑cardiopathy • Hyponyms …   Useful english dictionary

  • Arrhythmia absoluta — Vorhofflimmern ist eine vorübergehende (paroxysmale oder intermittierende) oder dauerhafte (permanente) Herzrhythmusstörung mit ungeordneter Tätigkeit der Herzvorhöfe. Gebräuchliche Abkürzungen sind AF oder AFib (von englisch Atrial fibrillation) …   Deutsch Wikipedia

  • Arrhythmia, sinus — The normal increase in heart rate that occurs during inspiration (when you breathe in). This is a natural response and is more accentuated in children than adults. The sinus refers to the natural pacemaker of the heart which is called the… …   Medical dictionary

  • arrhythmia — noun Etymology: New Latin, from Greek, lack of rhythm, from arrhythmos unrhythmical, from a + rhythmos rhythm Date: circa 1860 an alteration in rhythm of the heartbeat either in time or force …   New Collegiate Dictionary

  • arrhythmia — noun An irregular heartbeat …   Wiktionary

  • arrhythmia — n. irregular heartbeat (Medicine) …   English contemporary dictionary

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”