Nov 12, 2013

Integrated rate-dependent and dual pathway AV nodal functions: principles and assessment framework

American Journal of Physiology. Heart and Circulatory Physiology
Jacques Billette, Rafik Tadros

Abstract

The atrioventricular (AV) node conducts slowly and has a long refractory period. These features sustain the filtering of atrial impulses and hence are often modulated to optimize ventricular rate during supraventricular tachyarrhythmias. The AV node is also the site of a clinically common reentrant arrhythmia. Its function is assessed for a variety of purposes from its responses to a premature protocol (S1S2, test beats introduced at different cycle lengths) repeatedly performed at different basic rates and/or to an incremental pacing protocol (increasingly faster rates). Puzzlingly, resulting data and interpretation differ with protocols as well as with chosen recovery and refractory indexes, and are further complicated by the presence of built-in fast and slow pathways. This problem applies to endocavitary investigations of arrhythmias as well as to many experimental functional studies. This review supports an integrated framework of rate-dependent and dual pathway AV nodal function that can account for these puzzling characteristics. The framework was established from AV nodal responses to S1S2S3 protocols that, compared with standard S1S2 protocols, allow for an orderly quantitative dissociation of the different factors inv...Continue Reading

  • References57
  • Citations3

References

  • References57
  • Citations3

Citations

Mentioned in this Paper

Myocardial Contraction
Supraventricular Tachyarrhythmia
Biochemical Pathway
Refractory Period, Electrophysiological
Sustain
Refractory Period
Structure of Atrioventricular Node
NODAL gene
Heart Ventricle
Heart Atrium

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