What question did this study set out to answer?

To evaluate how electrode separation, interstimulus intervals, and anatomical positioning affect the reproducibility of ventricular fibrillation threshold measurements.

September 1, 1961American Journal of Physiology-Legacy Content

Ventricular fibrillation threshold

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Population

Dogs (preclinical model)

Comparison

Measurement of ventricular fibrillation… vs Different electrode separations, stimulus…

Design

Preclinical

Authors

RVRobert A. vanTynUniversity of Minnesota LMLloyd D. MacLeanMontreal General Hospital

Discussion

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Implication

Standardized electrode spacing and intervals are essential for reproducible VFT in canine models; leaves open translation to human arrhythmia research.

Key Points

To evaluate how electrode separation, interstimulus intervals, and anatomical positioning affect the reproducibility of ventricular fibrillation threshold measurements.
Applied single rectangular electrical stimuli directly to the epicardium of canine hearts using surface bipolar electrodes.
Systematically tested electrode separations of 2–4 mm versus 10–30 mm, stimulus delivery intervals of 3–4 beats versus 10–15 beats, and electrode placement at the left ventricular base versus apex.
Bipolar electrodes spaced 10–30 mm apart with 10–15 cycles between stimuli produced stable and reproducible ventricular fibrillation thresholds in individual dogs, whereas 2–4 mm spacing or placement on coagulated epicardium resulted in highly variable, elevated, or unobtainable thresholds.
Ventricular fibrillation thresholds were significantly lower when electrical stimuli were delivered 3–4 beats apart compared to intervals of 10–15 beats.
Threshold values were significantly higher at the base of the left ventricle than at the apex.

Structured PICO

Population

Dogs (preclinical model)

Intervention

Measurement of ventricular fibrillation threshold (VFT) using single rectangular stimuli applied directly to the heart surface, varying electrode separation, stimulus intervals, and anatomical positions

Comparator

Different electrode separations (10-30 mm vs 2-4 mm), stimulus intervals (10-15 cycles vs 3-4 beats), and anatomical positions (base vs apex of left ventricle)

Outcome

Ventricular fibrillation threshold (VFT)surrogate

Methodological factors such as electrode separation, stimulus interval, and anatomical position significantly influence the measurement of ventricular fibrillation threshold in experimental models.

Cite This Study

vanTyn et al. (1961) studied this question.

synapsesocial.com/papers/6a7f3eb7da2615c795b3abf7 https://doi.org/10.1152/ajplegacy.1961.201.3.457

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Implication

Standardized electrode spacing and intervals are essential for reproducible VFT in canine models; leaves open translation to human arrhythmia research.

Ventricular fibrillation threshold

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Ventricular fibrillation threshold

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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