Synergistic antiarrhythmic effect of combining inhibition of Ca(2+)-activated K(+) (SK) channels and voltage-gated Na(+) channels in an isolated heart model of atrial fibrillation

TY - JOUR

T1 - Synergistic antiarrhythmic effect of combining inhibition of Ca(2+)-activated K(+) (SK) channels and voltage-gated Na(+) channels in an isolated heart model of atrial fibrillation

AU - Kirchhoff, Jeppe Egedal

AU - Goldin Diness, Jonas

AU - Sheykhzade, Majid

AU - Grunnet, Morten

AU - Jespersen, Thomas

N1 - Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

PY - 2015/2/1

Y1 - 2015/2/1

N2 - BACKGROUND: Application of antiarrhythmic compounds is limited by both proarrhythmic and extracardiac toxicities, as well as incomplete antiarrhythmic efficacy. An improved antiarrhythmic potential may be obtained by combining antiarrhythmic drugs with different modes of action, and a reduction of the adverse effect profile could be an additional advantage if compound concentrations could be reduced.OBJECTIVE: The purpose of this study was to test the hypothesis that combined inhibition of Ca(2+)-activated K(+) channels (SK channels) and voltage-gated Na(+) channels, in concentrations that would be subefficacious as monotherapy, may prevent atrial fibrillation (AF) and have reduced proarrhythmic potential in the ventricles.METHODS: Subefficacious concentrations of ranolazine, flecainide, and lidocaine were tested alone or in combination with the SK channel blocker N-(pyridin-2-yl)-4-(pyridin-2-yl)thiazol-2-amine (ICA) in a Langendorff-perfused guinea pig heart model in which AF was induced after acetylcholine application and burst pacing.RESULTS: AF duration was reduced when both flecainide and ranolazine were combined with ICA in doses that did not reduce AF as monotherapy. At higher concentrations, both flecainide and ranolazine revealed proarrhythmic properties.CONCLUSION: A synergistic effect in AF treatment was obtained by combining low concentrations of SK and Na(+) channel blockers.

AB - BACKGROUND: Application of antiarrhythmic compounds is limited by both proarrhythmic and extracardiac toxicities, as well as incomplete antiarrhythmic efficacy. An improved antiarrhythmic potential may be obtained by combining antiarrhythmic drugs with different modes of action, and a reduction of the adverse effect profile could be an additional advantage if compound concentrations could be reduced.OBJECTIVE: The purpose of this study was to test the hypothesis that combined inhibition of Ca(2+)-activated K(+) channels (SK channels) and voltage-gated Na(+) channels, in concentrations that would be subefficacious as monotherapy, may prevent atrial fibrillation (AF) and have reduced proarrhythmic potential in the ventricles.METHODS: Subefficacious concentrations of ranolazine, flecainide, and lidocaine were tested alone or in combination with the SK channel blocker N-(pyridin-2-yl)-4-(pyridin-2-yl)thiazol-2-amine (ICA) in a Langendorff-perfused guinea pig heart model in which AF was induced after acetylcholine application and burst pacing.RESULTS: AF duration was reduced when both flecainide and ranolazine were combined with ICA in doses that did not reduce AF as monotherapy. At higher concentrations, both flecainide and ranolazine revealed proarrhythmic properties.CONCLUSION: A synergistic effect in AF treatment was obtained by combining low concentrations of SK and Na(+) channel blockers.

U2 - 10.1016/j.hrthm.2014.12.010

DO - 10.1016/j.hrthm.2014.12.010

M3 - Journal article

C2 - 25496982

SN - 1547-5271

VL - 12

SP - 409

EP - 418

JO - Heart Rhythm

JF - Heart Rhythm

IS - 2

ER -