The muscular network of the sheep right atrium and frequency-dependent breakdown of wave propagation

The Anatomical Record. Part A, Discoveries in Molecular, Cellular, and Evolutionary Biology
Omer Berenfeld, Alexey V Zaitsev

Abstract

The complex branching structure of the right atrium (RA) muscular network may provide the substrate for complex patterns of propagation during atrial fibrillation (AF). As AF results in some cases from stable sources in the left atrium (LA) with fibrillatory conduction toward the RA, we hypothesize that periodic input to the RA at an exceedingly high frequency results in disorganized wave propagation associated with the complex structure of the RA. Optical mapping was performed in isolated coronary-perfused sheep RA. Rhythmic pacing of Bachmann's bundle allowed well-controlled and realistic conditions for LA-driven RA. Pacing at increasingly higher frequencies led to increasing delays in activation distal to major branching sites of the Crista terminalis and pectinate bundles, culminating in spatially distributed intermittent blockade at and above approximately 6.5 Hz. At this breakdown frequency, the dominant frequencies of the RA response activity became spatially nonuniform. Such frequency-dependent changes were independent of action potential duration. Rather, the spatial boundaries between proximal and distal frequencies correlated well with branch sites of the pectinate musculature. Thus, there exists a breakdown frequenc...Continue Reading

References

Sep 1, 1996·Journal of Cardiovascular Electrophysiology·T Satoh, D P Zipes
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Citations

Dec 17, 2008·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Hakan Oral
Sep 12, 2009·Pacing and Clinical Electrophysiology : PACE·David E KrummenSanjiv M Narayan
Dec 17, 2014·PloS One·Michael C BressanTakashi Mikawa
Dec 19, 2017·Journal of Atrial Fibrillation·Lucaz GadenzDamian P Redfearn
Mar 17, 2012·Circulation. Arrhythmia and Electrophysiology·Jichao ZhaoBruce H Smaill
Dec 15, 2010·Journal of Cardiovascular Pharmacology·Sanne de JongJacques M T de Bakker
Feb 14, 2006·Current Opinion in Cardiology·Damian Paul Redfearn, Raymond Yee
May 9, 2006·American Journal of Physiology. Heart and Circulatory Physiology·David SedmeraRobert G Gourdie

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