What question did this study set out to answer?

To demonstrate functional reentry during ventricular fibrillation and elucidate the mechanism behind verapamil-mediated conversion of ventricular fibrillation to ventricular tachycardia.

March 31, 2000Circulation ResearchOpen Access

A Mechanism of Transition From Ventricular Fibrillation to Tachycardia

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Population

10 isolated Langendorff-perfused rabbit hearts and computer simulations

Comparison

Verapamil perfusion (2x10 mol/L) for 20 minutes vs Control (baseline) and washout

Design

Preclinical

Follow-up

20 minutes

Authors

FSFaramarz H. SamieColumbia University Irving Medical Center RMRavi MandapatiLoma Linda University RGRichard A. GrayCenter for Devices and Radiological Health

Discussion

Member takes

Implication

Hypothesis-generating for rotor-targeted VF organization in animals; leaves open translation to human antiarrhythmic therapy.

Key Points

To demonstrate functional reentry during ventricular fibrillation and elucidate the mechanism behind verapamil-mediated conversion of ventricular fibrillation to ventricular tachycardia.
Evaluated optical activation patterns in isolated Langendorff-perfused rabbit hearts (N=10) without electromechanical uncouplers using high-resolution fluorescent video imaging, ECG, 2D phase analysis, and computer modeling.
Assessed cardiac electrophysiological parameters across baseline control, verapamil perfusion (2x10^-6 mol/L), and subsequent drug washout phases.
Verapamil decreased the dominant frequency of ventricular fibrillation from 16.2±0.7 Hz to 13.5±0.6 Hz (P<0.007) and expanded rotor core area from 4.5±0.6 mm² to 9.2±0.5 mm² (P=0.0002).
Wavefront fragmentation declined via a 3-fold reduction in phase singularity density from 1.04±0.12 PSs/cm² to 0.32±0.06 PSs/cm² (P=0.0008), an effect that reversed upon washout.

Structured PICO

Population

10 isolated Langendorff-perfused rabbit hearts and computer simulations

Intervention

Verapamil perfusion (2x10(-6) mol/L) for 20 minutes

Comparator

Control (baseline) and washout

Outcome

Dominant frequency of VF, density of phase singularities (PSs) on the ventricular epicardial surface, and core area of transiently appearing rotorssurrogate

Verapamil-induced conversion of VF to VT is driven by a reduction in rotor frequency and decreased wavefront fragmentation, increasing the core area of rotors.

Cite This Study

Samie et al. (2000) studied this question.

synapsesocial.com/papers/6a9524342ea3449151e61a50 https://doi.org/10.1161/01.res.86.6.684

Topics

Ventricular arrhythmias

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A Mechanism of Transition From Ventricular Fibrillation to Tachycardia

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Topics

A Mechanism of Transition From Ventricular Fibrillation to Tachycardia

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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