What question did this study set out to answer?

To examine whole-heart transmembrane potential patterns during and immediately following fibrillation-inducing electrical shocks.

October 15, 1999Circulation ResearchOpen Access

Shock-Induced Figure-of-Eight Reentry in the Isolated Rabbit Heart

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Why the study?

Does shock delivery at varying strengths and coupling intervals induce reentry arrhythmias in isolated rabbit hearts?

Key Points

To examine whole-heart transmembrane potential patterns during and immediately following fibrillation-inducing electrical shocks.
Dual charge-coupled device cameras recorded optical transmembrane potentials simultaneously from anterior and posterior epicardial surfaces of apex-paced isolated rabbit hearts.
Shocks were delivered across 3 current intensities (0.75, 1.5, and 2.25 A) at 6 coupling intervals between 130 and 230 ms.
Short coupling intervals (<180 ms) provoked extensive hyperpolarization and counterrotating waves, producing reentrant first postshock beats in 90% of episodes and inducing arrhythmias in 98%.
Long coupling intervals (>180 ms) led to graded depolarization, generating reentrant first postshock beats in 18% of episodes and inducing arrhythmias in 35%.
Increasing shock strength and coupling interval displaced the site of reentry formation, supporting the critical point hypothesis of arrhythmia induction.

Structured PICO

Does shock delivery at varying strengths and coupling intervals induce reentry arrhythmias in isolated rabbit hearts?

Population

Isolated rabbit hearts

Intervention

Fibrillation-inducing shocks delivered via coils in the right ventricle and atop the left atrium at 3 strengths (0.75, 1.5, and 2.25 A) and 6 coupling intervals (130 to 230 ms)

Comparator

Different shock strengths and coupling intervals

Outcome

Patterns of transmembrane potential (depolarization and repolarization) and arrhythmia induction (reentry)surrogate

In isolated rabbit hearts, shock-induced arrhythmia induction is highly dependent on the coupling interval, with short intervals causing hyperpolarization and a higher rate of reentry, consistent with the critical point hypothesis.

Discussion

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Implication

Short coupling intervals favor reentrant arrhythmias post-shock in rabbit hearts; extends critical point hypothesis but leaves clinical translation untested.

Cite This Study

Banville et al. (1999) studied this question.

synapsesocial.com/papers/6a6fbcafe5469ee92be096c2 https://doi.org/10.1161/01.res.85.8.742

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Implication

Short coupling intervals favor reentrant arrhythmias post-shock in rabbit hearts; extends critical point hypothesis but leaves clinical translation untested.

Shock-Induced Figure-of-Eight Reentry in the Isolated Rabbit Heart

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Shock-Induced Figure-of-Eight Reentry in the Isolated Rabbit Heart

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Also Consider

Also Consider