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Updated: May 23, 2026
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Estimating Bilateral Atrial Function by Cardiovascular Magnetic Resonance Feature Tracking in Patients with Paroxysmal Atrial Fibrillation
Published on: July 20, 2022
Atrioventricular node functional remodeling induced by atrial fibrillation
Youhua Zhang1, Todor N Mazgalev
1Department of Cardiovascular Medicine and Molecular Cardiology, Cleveland Clinic, Cleveland, Ohio, USA. yzhang49@nyit.edu
Heart Rhythm
|April 24, 2012
Summary
Atrial fibrillation (AF) causes significant remodeling in the atrioventricular node (AVN), leading to slower ventricular rates. This AVN remodeling, particularly slow-pathway dominance, highlights ablation
Area of Science:
- Electrophysiology
- Cardiovascular Research
- Atrial Fibrillation
Background:
- The atrioventricular node (AVN) is crucial for regulating ventricular rate during atrial fibrillation (AF).
- While AF causes significant atrial remodeling, AVN remodeling during AF remains poorly understood.
Purpose of the Study:
- To investigate functional electrophysiological remodeling of the AVN during atrial fibrillation.
- To determine if AF induces changes in AVN conduction properties and pathways.
Main Methods:
- In vitro electrophysiological studies in rabbits with induced AF.
- In vivo studies in dogs with chronic AF.
- Utilized His-electrogram alternans to assess AVN dual-pathway function (fast and slow pathways).
Main Results:
- Rabbits with AF exhibited prolonged AVN conduction time and effective refractory period compared to controls.
- AF led to an earlier transition to slow-pathway (SP) conduction and a slower ventricular rate.
- In dogs with chronic AF, similar AVN remodeling and slower ventricular rates were observed.
Conclusions:
- Long-term AF induces significant functional remodeling in the AVN.
- This remodeling results in a spontaneous slowing of the ventricular rate.
- The observed dominance of the SP in AF suggests its potential as a target for ablation in ventricular rate control.
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