PulseTrendingJournal ClubResearchersJournalsExplore
Instagram
HomeTrendingJournal ClubExplore
Synapse
⌘+K
Synapse
January 1, 2010Frontiers in PhysiologyOpen Access

Anti- or profibrillatory effects of Na+ channel blockade depend on the site of application relative to gradients in repolarization

View Full Paper
Ask AI
Bookmark
Share

Why the study?

Does the site of sodium channel blockade application relative to repolarization gradients determine its anti- or profibrillatory effects in isolated porcine hearts?

Population

Isolated porcine hearts with induced repolarization heterogeneity via selective perfusion of vascular beds

Comparison

Flecainide infusion in the pinacidil domain or… vs Baseline state prior to flecainide infusion

Design

Preclinical

Key result

Sodium channel blockade with flecainide was antifibrillatory when applied to myocardium with a short refractory period, but profibrillatory when applied to myocardium with a long refractory period.

Authors

RCRuben Coronel

Discussion

Loading...

Member takes

Overview

Site-specific flecainide effects on fibrillation may depend on local refractory period; leaves open translation to human antiarrhythmic strategies.

Structured PICO

Does the site of sodium channel blockade application relative to repolarization gradients determine its anti- or profibrillatory effects in isolated porcine hearts?

P
Population
Isolated porcine hearts (n=8) with induced repolarization heterogeneity via selective perfusion of vascular beds (sotalol 220 μM in one bed, pinacidil 80 μM in adjacent bed)
I
Intervention
Flecainide infusion in the pinacidil domain (short refractory period) or sotalol domain (long refractory period)
C
Comparator
Baseline state prior to flecainide infusion
O
Outcome
Induction of ventricular fibrillation (VF) and changes in Fibrillation Factor (FF)surrogate

Main Result

p-value: p=<0.001

Sodium channel blockade exhibits anti- or profibrillatory effects depending on whether it is applied to myocardium with a short or long refractory period, providing a mechanistic basis for these opposing effects.

Limitations

  • Restricted time frame in which measurements can be made, preventing study of long-term effects
  • Only epicardial mapping was performed, lacking information on intramural gradients
  • Artificial model of VF inducibility based on large and steep gradients in repolarization

Cite This Study

Ruben Coronel (2010) studied Ventricular fibrillation (n=8). Flecainide vs. Baseline (prior to flecainide) was evaluated on Activation time delay of basic and premature beats (S1 and S2) induced by flecainide (p=<0.001). Sodium channel blockade with flecainide was antifibrillatory when applied to myocardium with a short refractory period, but profibrillatory when applied to myocardium with a long refractory period.

synapsesocial.com/papers/6a0f7a292badbc352afe39b8https://doi.org/10.3389/fphys.2010.00010
View Full Paper
Ask AI
Bookmark
Share