2011
Biophysical properties and functional consequences of reactive oxygen species (ROS)‐induced ROS release in intact myocardium
Biary N, Xie C, Kauffman J, Akar FG. Biophysical properties and functional consequences of reactive oxygen species (ROS)‐induced ROS release in intact myocardium. The Journal Of Physiology 2011, 589: 5167-5179. PMID: 21825030, PMCID: PMC3225672, DOI: 10.1113/jphysiol.2011.214239.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsAntioxidantsArrhythmias, CardiacCyclosporineDiazepamEthidiumFluorescenceFluorescent DyesHydrogen PeroxideIn Vitro TechniquesIntracellular MembranesMitochondrial Membrane Transport ProteinsMitochondrial Permeability Transition PoreMyocardiumOrganometallic CompoundsOxidantsOxidative StressRatsSalicylatesSuperoxidesVoltage-Dependent Anion ChannelsConceptsIncidence of arrhythmiasIntact myocardiumOxidative stressMitochondrial permeability transition poreReactive oxygen speciesSustained ventricular tachycardiaROS releaseExposure of heartsGlobal oxidative stressPerfusion of heartsSuperoxide dismutase/catalase mimetic EUK-134Functional consequencesOS protocolArrhythmia scoreAcute modelDihydroethidium fluorescenceUntreated heartsVentricular tachycardiaVentricular fibrillationOxygen speciesArrhythmic consequencesElevated ROS levelsRat heartEUK-134Perfusion
2010
Optical imaging of mitochondrial function uncovers actively propagating waves of mitochondrial membrane potential collapse across intact heart
Lyon AR, Joudrey PJ, Jin D, Nass RD, Aon MA, O'Rourke B, Akar FG. Optical imaging of mitochondrial function uncovers actively propagating waves of mitochondrial membrane potential collapse across intact heart. Journal Of Molecular And Cellular Cardiology 2010, 49: 565-575. PMID: 20624394, PMCID: PMC3081287, DOI: 10.1016/j.yjmcc.2010.07.002.Peer-Reviewed Original Research
2009
Mechanoelectrical remodeling and arrhythmias during progression of hypertrophy
Jin H, Chemaly ER, Lee A, Kho C, Hadri L, Hajjar RJ, Akar FG. Mechanoelectrical remodeling and arrhythmias during progression of hypertrophy. The FASEB Journal 2009, 24: 451-463. PMID: 19825979, PMCID: PMC2812033, DOI: 10.1096/fj.09-136622.Peer-Reviewed Original ResearchConceptsConduction delayLeft ventricular mechanical dysfunctionEnd-stage heart failureTissue levelsVentricular mechanical dysfunctionIncidence of arrhythmiasSudden cardiac deathZO-1Pressure overload hypertrophyAction potential prolongationProgression of hypertrophyDisease developmentLV dysfunctionCardiac deathDephosphorylation of Cx43Heart failureAortic bandingElectrical remodelingVentricular tachycardiaMechanical dysfunctionOverload hypertrophyElectrophysiological changesRat modelPotential prolongationProtein ZO-1
2003
Phenotypic differences in transient outward K+ current of human and canine ventricular myocytes: insights into molecular composition of ventricular Ito
Akar FG, Wu RC, Deschenes I, Armoundas AA, Piacentino V, Houser SR, Tomaselli GF. Phenotypic differences in transient outward K+ current of human and canine ventricular myocytes: insights into molecular composition of ventricular Ito. AJP Heart And Circulatory Physiology 2003, 286: h602-h609. PMID: 14527940, DOI: 10.1152/ajpheart.00673.2003.Peer-Reviewed Original ResearchConceptsTransient outwardPhenotypic differencesKv channel-interacting proteinsIndependent transient outwardChannel-interacting proteinsProtein chemical techniquesSteady-state inactivationCanine ventricular myocytesWestern blot analysisElectrical remodelingChannel subunit genesMonoexponential time coursePharmacological sensitivityVentricular repolarizationCardiac diseaseElectrophysiological roleCanine ventricularHuman cardiac diseasePosttranslational modificationsVentricular myocytesSubunit genePharmacological propertiesDiseased heartPhenotypic propertiesOxidative stressTransmural Electrophysiological Heterogeneities Underlying Arrhythmogenesis in Heart Failure
Akar FG, Rosenbaum DS. Transmural Electrophysiological Heterogeneities Underlying Arrhythmogenesis in Heart Failure. Circulation Research 2003, 93: 638-645. PMID: 12933704, DOI: 10.1161/01.res.0000092248.59479.ae.Peer-Reviewed Original ResearchMeSH KeywordsAction PotentialsAnimalsArrhythmias, CardiacDogsElectrophysiologyHeartHeart FailureIn Vitro TechniquesMaleConceptsPolymorphic ventricular tachycardiaHeart failureQT interval prolongationQT intervalM cellsConduction blockAPD prolongationTransmural wallAction potential duration prolongationRapid ventricular pacingTransmural heterogeneityFunctional conduction blockVentricular tachyarrhythmiasPremature impulsesSubepicardial zoneVentricular pacingVentricular tachycardiaHF phenotypesDuration prolongationCanine wedge preparationSelective prolongationDecremental conductionAction potentialsOptical action potentialsVentricular wall
2002
Unique Topographical Distribution of M Cells Underlies Reentrant Mechanism of Torsade de Pointes in the Long-QT Syndrome
Akar FG, Yan GX, Antzelevitch C, Rosenbaum DS. Unique Topographical Distribution of M Cells Underlies Reentrant Mechanism of Torsade de Pointes in the Long-QT Syndrome. Circulation 2002, 105: 1247-1253. PMID: 11889021, DOI: 10.1161/hc1002.105231.Peer-Reviewed Original ResearchConceptsLong QT syndromeSpecific ion channel mutationsCongenital long QT syndromeM cellsQT interval prolongationIon channel mutationsInterval prolongationReentrant mechanismTdP arrhythmiasConduction blockCanine wedge preparationReentrant circuitTransmural dispersionLeft ventricleAction potentialsTransmural wallIntact myocardiumTopographical distributionChannel mutationsWedge preparationsMidmyocardial cellsRepolarizationLQT2Cellular basisElectrical instability
1998
Modulated Dispersion Explains Changes in Arrhythmia Vulnerability During Premature Stimulation of the Heart
Laurita K, Girouard S, Akar F, Rosenbaum D. Modulated Dispersion Explains Changes in Arrhythmia Vulnerability During Premature Stimulation of the Heart. Circulation 1998, 98: 2774-2780. PMID: 9851966, DOI: 10.1161/01.cir.98.24.2774.Peer-Reviewed Original ResearchConceptsVentricular fibrillation thresholdSingle premature stimulusPremature stimuliArrhythmia vulnerabilityBaseline levelsPremature stimulationS1S2 intervalRepolarization gradientsGuinea pig heartsBaseline pacingFibrillation thresholdArrhythmogenic substrateVentricular fibrillationVentricular sitesStimulus-induced changesVentricular repolarizationCoupling intervalCardiac arrhythmiasS2 beatElectrophysiological propertiesAction potentialsOptical action potentialsHeterogeneous electrophysiological propertiesPig heartsRepolarization