What does this research mean for the field?

Vagally induced atrial fibrillation in intact hearts is triggered by widely distributed ectopic premature depolarizations and can be maintained by a single stable reentrant circuit. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To investigate the activation sequence and spatial distribution of atrial fibrillation induced by vagal nerve stimulation in intact canine hearts.

September 1, 2000Journal of Cardiovascular Electrophysiology

Spatial Distribution and Frequency Dependence of Arrhythmogenic Vagal Effects in Canine Atria

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Why the study?

Does vagal stimulation induce atrial premature depolarizations and atrial fibrillation in intact dog hearts?

Key Points

To investigate the activation sequence and spatial distribution of atrial fibrillation induced by vagal nerve stimulation in intact canine hearts.
Delivered vagal stimulation (10 to 50 Hz, 1 msec, 15 V, 5-second trains) in open-chest canine models (N=10).
Performed high-density epicardial mapping across both atria using 254 unipolar electrodes to record activation sequences and circuit dynamics during the first 10 cycles and sustained phases of atrial fibrillation.
Vagal stimulation induced atrial premature depolarizations (APDs) and/or atrial fibrillation (AF) in 8 of 10 dogs (80%), with higher stimulation frequencies directly increasing arrhythmia occurrence.
Ectopic APDs emerged from widely distributed atrial sites—most commonly the right atrial appendage—with a single APD proving sufficient to trigger reentrant AF.
Initial AF activation involved fewer than 3 to 4 unstable reentrant circuits simultaneously, and sustained AF was predominantly driven and maintained by a single leading stable reentrant circuit.

Structured PICO

Does vagal stimulation induce atrial premature depolarizations and atrial fibrillation in intact dog hearts?

Population

10 open chest dogs

Intervention

Vagal stimulation (10 to 50 Hz, 1 msec, 15 V, 5-sec trains)

Outcome

Occurrence of atrial premature depolarizations (APDs) and atrial fibrillation (AF), and activation sequence mappingsurrogate

Vagal stimulation in intact canine hearts induces ectopic APDs widely distributed over the atria, and sustained AF can be maintained by a single stable reentrant circuit.

Discussion

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Implication

Extends isolated-atrium reentry models to intact hearts; hypothesis-generating for vagal AF triggers with unclear human translation.

Cite This Study

Sharifov et al. (2000) studied this question.

synapsesocial.com/papers/6a1e16f949e88a0d41608bc2 https://doi.org/10.1111/j.1540-8167.2000.tb00176.x

Topics

Atrial fibrillation Persistent AF management

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