Determinants of Antidromic Wave Front Propagation During Entrainment of Reentrant Arrhythmias

Authors:
  • MWMary A. Woo
    Mary A. Woo
Publisher website
Google Scholar
Abstract
Antidromic Conduction. During entrainment or resetting of ventricular tachycardia, the distance a stimulated antidromic wave front propagates determines the degree of QRS fusion observed. Determinants of antidromic wave front propagation distance during stimulation at reentry circuit sites were studied in computer simulations of figure eight reentry circuits. When not limited by refractory tissue, antidromic propagation distance depended on the stimulus timing, the conduction velocity in the antidromic direction away from the stimulus site, and the time available for propagation before collision with a returning orthodromic wave front. The latter was determined by the conduction time through the circuit in the orthodromic direction from the stimulus site. Faster conduction from the stimulus site in the orthodromic direction relative to the antidromic direction diminished antidromic wave front propagation distance. Consequently, in circuits with heterogeneous conduction velocities, antidromic propagation distance was dependent on the location of the stimulus site. Stimulation in slow areas limited antidromic propagation distance, although increasing stimulus prematurity increased antidromic propagation distance markedly if the antidromic wave front reached faster tissue. These findings explain the ability of rapid or premature stimuli to entrain or reset tachycardia without producing detectable antidromic wave front effects (QRS fusion) on the surface electrocardiogram when the stimulation site is located centrally within slowly conducting areas in the reentry circuit. However, greater antidromic propagation occurs with stimulation at or near more rapidly conducting sites increasing the likelihood that antidromic effects will be seen on the surface electrocardiogram.

This publication has 20 references indexed in Scilit: