idioventricular rhythm

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id·i·o·ven·tric·u·lar rhyth·m

a slow independent ventricular rhythm under control of a ventricular center (which is, by definition, ectopic).
Synonym(s): ventricular rhythm

idioventricular rhythm

Etymology: Gk, idios, own; L, ventriculus, little belly; Gk, rhythmos
an independent cardiac rhythm caused by a repeated discharge of impulses at a rate of less than 100 beats/min from a focus within a ventricle.

id·i·o·ven·tric·u·lar rhythm

(id'ē-ō-ven-trik'yū-lăr ridh'ŭm)
A slow independent ventricular rhythm under control of an ectopic ventricular center; occurs in heart block and sinus arrest.
Synonym(s): ventricular rhythm.


a measured movement; the recurrence of an action or function at regular intervals.

alpha rhythm
a uniform rhythm of waves in the normal electroencephalogram.
beta rhythm
a rhythm in the electroencephalogram consisting of waves smaller than those of the alpha rhythm, having an average frequency of 25 per second, typical during periods of intense activity of the nervous system. See also electroencephalography.
biological r's
the cyclic changes that occur in physiological processes of living organisms; called also biorhythms. These rhythms are so persistent throughout the living kingdom that they probably should be considered a fundamental characteristic of life, as are growth, reproduction, metabolism and irritability. Many of the physiological rhythms occur in animals about every 24 hours (circadian rhythm). Examples include the peaks and troughs that are manifested in body temperature, vital signs, brain function and muscular activity. Biochemical analyses of urine, blood enzymes and plasma serum also have demonstrated rhythmic fluctuations in a 24-hour period.
It has long been believed that the cyclic changes observed in plants and animals were totally in response to environmental changes and, as such, were exogenous or of external origin. This hypothesis is now being rejected by some chronobiologists who hold that the biological rhythms are intrinsic to the organisms, and that the organisms possess their own physiological mechanism for keeping time. This mechanism has been called the 'biological clock'.
circadian rhythm
see circadian rhythm.
circamensual rhythm
that which occurs in cycles of about one month (30 days).
circannual rhythm
the recurrence of a phenomenon in cycles of about one year.
circaseptan rhythm
that which occurs in cycles of about 7 days (one week).
coupled rhythm
heartbeats occurring in pairs, the second beat of the pair usually being a ventricular premature beat.
escape rhythm
a heart rhythm initiated by lower centers when the sinoatrial node fails to initiate impulses, its rhythmicity is depressed, or its impulses are completely blocked.
gallop rhythm
an auscultatory finding of three or four heart sounds, the extra sounds by convention being in diastole and related to atrial contraction (fourth sound, presystolic gallop), to early rapid filling of a ventricle with an altered ventricular compliance (protodiastolic gallop), or to concurrence of atrial contraction and ventricular early rapid filling (summation gallop).
idioventricular rhythm
a series of ventricular escape complexes occuring at a regular rate.
infradian rhythm
the regular recurrence in cycles of more than 24 hours, as certain biological activities which occur at such intervals, regardless of conditions of illumination.
nodal rhythm
heart rhythm initiated in the specialized junctional tissue, i.e. the atrioventricular node and the main (His) bundle.
nyctohemeral rhythm
a day and night rhythm.
pendulum rhythm
alternation in the rhythm of the heart sounds in which the diastolic sound is equal in time, character and loudness to the systolic sound, the beat of the heart resembling the tick of a watch.
sinus rhythm
normal heart rhythm originating in the sinoatrial node.
Enlarge picture
Electrocardiogram showing normal sinus rhythm in a dog. By permission from Darke P, Kelly DF, Bonagura JD, Color Atlas of Veterinary Cardiology, Mosby, 1995
ultradian rhythm
the regular recurrence in cycles of less than 24 hours, as certain biological activities which occur at such intervals, regardless of conditions of illumination.
ventricular rhythm
the ventricular contractions which occur in cases of complete heart block.