atrioventricular dissociation
AV dissociation control of the atria by one pacemaker and of the ventricles by another, independent pacemaker; it may be due to heart block, to severe slowing of the sinus rhythm with activation of an ectopic pacemaker, to acceleration of an ectopic pacemaker that usurps control of the ventricles, or to a combination of factors. See also interference atrioventricular d. and isorhythmic atrioventricular d.
Medical dictionary.
2011.