2024
Top Stories: Mitochondrial origin of inherited cardiac arrhythmias
Akar F, Maack C. Top Stories: Mitochondrial origin of inherited cardiac arrhythmias. Heart Rhythm 2024, 21: 235-236. PMID: 38296456, PMCID: PMC10857749, DOI: 10.1016/j.hrthm.2023.10.020.Peer-Reviewed Original ResearchArrhythmias, CardiacHumans
2023
A unifying mechanism for the initiation of torsade de pointes: blurring the distinction between trigger and substrate
McKay M, Akar F. A unifying mechanism for the initiation of torsade de pointes: blurring the distinction between trigger and substrate. Cardiovascular Research 2023, 119: 333-335. PMID: 36869679, DOI: 10.1093/cvr/cvad033.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus Statements
2022
Humanized Dsp ACM Mouse Model Displays Stress-Induced Cardiac Electrical and Structural Phenotypes
Stevens TL, Manring HR, Wallace MJ, Argall A, Dew T, Papaioannou P, Antwi-Boasiako S, Xu X, Campbell SG, Akar FG, Borzok MA, Hund TJ, Mohler PJ, Koenig SN, El Refaey M. Humanized Dsp ACM Mouse Model Displays Stress-Induced Cardiac Electrical and Structural Phenotypes. Cells 2022, 11: 3049. PMID: 36231013, PMCID: PMC9562631, DOI: 10.3390/cells11193049.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsArrhythmias, CardiacArrhythmogenic Right Ventricular DysplasiaDesmoplakinsDisease Models, AnimalHeartHumansMicePhenotypeConceptsArrhythmogenic cardiomyopathyMouse modelStructural phenotypesFibro-fatty infiltrationFirst mouse modelHeart failureChamber dilationVentricular arrhythmiasPressure overloadArrhythmic eventsCardiac performanceCardiac stressSudden deathCardiovascular stressInherited disorderG variantConnexin 43MiceDesmosomal genesReduced expressionExternal stressorsACM familyDisease developmentMurine equivalentIncomplete penetranceA novel exosome-based therapy for post-MI arrhythmias
Cacheux M, Akar FG. A novel exosome-based therapy for post-MI arrhythmias. European Heart Journal 2022, 43: 2157-2159. PMID: 35325140, DOI: 10.1093/eurheartj/ehac155.Peer-Reviewed Original Research
2021
Right predominant electrical remodeling in a pure model of pulmonary hypertension promotes reentrant arrhythmias
Strauss B, Bisserier M, Obus E, Katz MG, Fargnoli A, Cacheux M, Akar JG, Hummel JP, Hadri L, Sassi Y, Akar FG. Right predominant electrical remodeling in a pure model of pulmonary hypertension promotes reentrant arrhythmias. Heart Rhythm 2021, 19: 113-124. PMID: 34563688, PMCID: PMC8742785, DOI: 10.1016/j.hrthm.2021.09.021.Peer-Reviewed Original ResearchConceptsPulmonary arterial hypertensionVT/VFExtrapulmonary toxicityPN ratsVentricular tachycardia/fibrillationCardiac magnetic resonance imagingRight ventricular hypertrophySprague-Dawley ratsMultiple reentrant circuitsConnexin 43 expressionMagnetic resonance imagingConnexin 43 phosphorylationRV activationArterial hypertensionMonocrotaline modelVentricular hypertrophyLeft pneumonectomyElectrical remodelingMyocardial fibrosisConduction slowingSevere formAP durationArrhythmic vulnerabilityReentrant circuitAP alternansArrhythmia Mechanism and Dynamics in a Humanized Mouse Model of Inherited Cardiomyopathy Caused by Phospholamban R14del Mutation
Raad N, Bittihn P, Cacheux M, Jeong D, Ilkan Z, Ceholski D, Kohlbrenner E, Zhang L, Cai CL, Kranias EG, Hajjar RJ, Stillitano F, Akar FG. Arrhythmia Mechanism and Dynamics in a Humanized Mouse Model of Inherited Cardiomyopathy Caused by Phospholamban R14del Mutation. Circulation 2021, 144: 441-454. PMID: 34024116, PMCID: PMC8456417, DOI: 10.1161/circulationaha.119.043502.Peer-Reviewed Original ResearchConceptsHuman PLNRapid pacingInterventricular activation delayHumanized mouse modelAction potential prolongationLocal conduction blockSteep repolarization gradientsArrhythmogenic featuresMacroreentrant circuitHemodynamic changesElectric remodelingElectrophysiological remodelingRight ventricleVentricular tachycardiaPotential prolongationSudden deathConduction blockMouse modelAdult knockArrhythmia susceptibilityAdrenergic stimulationStructural remodelingArrhythmogenic phenotypeArrhythmia mechanismsRegulatory protein phospholamban
2020
‘Social distancing’ of the neuronal nitric oxide synthase from its adaptor protein causes arrhythmogenic trigger-substrate interactions in long QT syndrome
Tieu A, Akar FG. ‘Social distancing’ of the neuronal nitric oxide synthase from its adaptor protein causes arrhythmogenic trigger-substrate interactions in long QT syndrome. Cardiovascular Research 2020, 117: 338-340. PMID: 32589704, PMCID: PMC7820852, DOI: 10.1093/cvr/cvaa179.Commentaries, Editorials and Letters
2019
Cardiomyocyte-Specific STIM1 (Stromal Interaction Molecule 1) Depletion in the Adult Heart Promotes the Development of Arrhythmogenic Discordant Alternans
Cacheux M, Strauss B, Raad N, Ilkan Z, Hu J, Benard L, Feske S, Hulot JS, Akar FG. Cardiomyocyte-Specific STIM1 (Stromal Interaction Molecule 1) Depletion in the Adult Heart Promotes the Development of Arrhythmogenic Discordant Alternans. Circulation Arrhythmia And Electrophysiology 2019, 12: e007382-e007382. PMID: 31726860, PMCID: PMC6867678, DOI: 10.1161/circep.119.007382.Peer-Reviewed Original ResearchConceptsVT/VFAPD alternansStore-operated CaVentricular tachycardia/ventricular fibrillationOptical action potential mappingAdult heartVT/Adult murine modelDiscordant alternansConduction velocity slowingSarcoplasmic reticulum CaArrhythmogenic discordant alternansInitial beatsEarly mortalityFlox/Poor survivalVentricular fibrillationDiscordant APD alternansMurine modelCardiac hypertrophyConduction velocityLittermate controlsAdult miceRapid pacingElectrophysiological substrate
2018
Intra-tracheal gene delivery of aerosolized SERCA2a to the lung suppresses ventricular arrhythmias in a model of pulmonary arterial hypertension
Strauss B, Sassi Y, Bueno-Beti C, Ilkan Z, Raad N, Cacheux M, Bisserier M, Turnbull IC, Kohlbrenner E, Hajjar RJ, Hadri L, Akar FG. Intra-tracheal gene delivery of aerosolized SERCA2a to the lung suppresses ventricular arrhythmias in a model of pulmonary arterial hypertension. Journal Of Molecular And Cellular Cardiology 2018, 127: 20-30. PMID: 30502350, PMCID: PMC6561115, DOI: 10.1016/j.yjmcc.2018.11.017.Peer-Reviewed Original ResearchMeSH KeywordsAction PotentialsAerosolsAnimalsArrhythmias, CardiacConnexin 43Disease Models, AnimalGene Transfer TechniquesGenetic TherapyHeart Conduction SystemHumansMalePotassium ChannelsPulmonary Arterial HypertensionRats, Sprague-DawleyRNA, MessengerSarcoplasmic Reticulum Calcium-Transporting ATPasesTracheaConceptsPulmonary arterial hypertensionSudden cardiac deathVentricular tachyarrhythmiasCTRL heartsExpression of Cx43Conduction velocityArterial hypertensionHeart rateAP durationAdvanced pulmonary arterial hypertensionIncidence of VTOptical action potential mappingPacing-induced ventricular tachyarrhythmiasRisk of VTAEP substrateElectro-mechanical dysfunctionImpaired chronotropic responseMinimal conduction velocitiesRight ventricular failureSustained ventricular tachyarrhythmiasAPD heterogeneityPulmonary vascular remodelingRapid heart rateAge-matched ratsIntra-tracheal deliveryAcute Left Ventricular Unloading Reduces Atrial Stretch and Inhibits Atrial Arrhythmias
Ishikawa K, Watanabe S, Lee P, Akar FG, Lee A, Bikou O, Fish K, Kho C, Hajjar RJ. Acute Left Ventricular Unloading Reduces Atrial Stretch and Inhibits Atrial Arrhythmias. Journal Of The American College Of Cardiology 2018, 72: 738-750. PMID: 30092950, PMCID: PMC6160394, DOI: 10.1016/j.jacc.2018.05.059.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsArrhythmias, CardiacAtrial FibrillationFemaleMaleMyocardial InfarctionStroke VolumeSwineVentricular Function, LeftConceptsLV end-diastolic pressureEnd-diastolic pressureLV unloadingMyocardial infarctionSubacute myocardial infarctionPressure-volume loopsLA pressureAortic regurgitationRyanodine receptor phosphorylationLA tissuesLV loadingReduced LV ejection fractionAtrial arrhythmia inducibilityLV assist deviceLV ejection fractionMean LA pressureLeft ventricular performancePressure-volume catheterMaximum LA volumeLV loading conditionsReceptor phosphorylationMedian 55NOX2 levelsArrhythmia inducibilityAtrial stretchOptical Action Potential Mapping in Acute Models of Ischemia–Reperfusion Injury: Probing the Arrhythmogenic Role of the Mitochondrial Translocator Protein
Ilkan Z, Strauss B, Campana C, Akar FG. Optical Action Potential Mapping in Acute Models of Ischemia–Reperfusion Injury: Probing the Arrhythmogenic Role of the Mitochondrial Translocator Protein. Methods In Molecular Biology 2018, 1816: 133-143. PMID: 29987816, DOI: 10.1007/978-1-4939-8597-5_10.Peer-Reviewed Original ResearchConceptsOptical action potential mappingIschemia-reperfusion injuryTranslocator proteinPost-ischemic arrhythmiasIonotropic propertiesPostischemic arrhythmiasR injuryHypertensive ratsAcute modelArrhythmogenic roleElectrophysiological substrateElectrophysiological propertiesArrhythmia mechanismsPharmacological inhibitionIntact heartInjuryTSPO ligandsMitochondrial translocator proteinArrhythmiasTSPO geneHeartPatientsRatsQuantitative assessmentIncidence
2015
The Classically Cardioprotective Agent Diazoxide Elicits Arrhythmias in Type 2 Diabetes Mellitus
Xie C, Hu J, Motloch LJ, Karam BS, Akar FG. The Classically Cardioprotective Agent Diazoxide Elicits Arrhythmias in Type 2 Diabetes Mellitus. Journal Of The American College Of Cardiology 2015, 66: 1144-1156. PMID: 26337994, PMCID: PMC4560843, DOI: 10.1016/j.jacc.2015.06.1329.Peer-Reviewed Original ResearchConceptsAction potential durationVentricular tachyarrhythmiasT2DM heartsIschemia-induced ventricular tachyarrhythmiasOptical action potential mappingType 2 diabetes mellitusAdenosine triphosphate-sensitive potassium channelsMitochondrial adenosine triphosphate-sensitive potassium channelsTriphosphate-sensitive potassium channelsLow-dose diazoxideFree fatty acid levelsIncidence of arrhythmiasNormal Sprague-Dawley ratsSprague-Dawley ratsOnset of arrhythmiasMessenger ribonucleic acid expressionFatty acid levelsRibonucleic acid expressionAPD adaptationElicit arrhythmiasUntreated T2DMIschemic eventsDiabetes mellitusDiabetic patientsIschemic challengeGene therapy to restore electrophysiological function in heart failure
Motloch LJ, Akar FG. Gene therapy to restore electrophysiological function in heart failure. Expert Opinion On Biological Therapy 2015, 15: 803-817. PMID: 25865107, PMCID: PMC5547747, DOI: 10.1517/14712598.2015.1036734.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsArrhythmias, CardiacBrugada SyndromeCardiac Conduction System DiseaseElectrocardiographyGenetic TherapyHeart Conduction SystemHeart FailureHumansConceptsHeart failureHF patientsMajor public health epidemicPro-arrhythmic activitySafe therapeutic optionSudden cardiac deathCause of morbidityGene therapyPublic health epidemicAbnormal excitabilityCardiac deathTherapeutic optionsTherapeutic effectMyocardial conductionHeart rateLethal arrhythmiasGene therapy approachesElectrophysiological functionUnmet needArrhythmogenic disordersGene-based approachesCalcium cyclingHealth epidemicCardiac gene therapyConduction system
2014
Gene therapies for arrhythmias in heart failure
Akar FG, Hajjar RJ. Gene therapies for arrhythmias in heart failure. Pflügers Archiv - European Journal Of Physiology 2014, 466: 1211-1217. PMID: 24566976, PMCID: PMC4070506, DOI: 10.1007/s00424-014-1485-3.Peer-Reviewed Original ResearchMeSH KeywordsAction PotentialsAnimalsArrhythmias, CardiacCalcium SignalingConnexin 43Genetic TherapyHeart FailureHumansIon Channels
2013
Mitochondrial targets for arrhythmia suppression: is there a role for pharmacological intervention?
Akar FG. Mitochondrial targets for arrhythmia suppression: is there a role for pharmacological intervention? Journal Of Interventional Cardiac Electrophysiology 2013, 37: 249-258. PMID: 23824789, DOI: 10.1007/s10840-013-9809-3.Peer-Reviewed Reviews, Practice Guidelines, Standards, and Consensus StatementsMeSH KeywordsAnti-Arrhythmia AgentsArrhythmias, CardiacHumansMitochondriaMitochondrial DiseasesModels, CardiovascularConceptsMitochondrial targetsMitochondrial dysfunctionCritical cellular functionsCell death pathwaysCellular redox statusIon channel functionMitochondrial networkCellular functionsDeath pathwaysMitochondrial originIschemia-reperfusion injuryCommon cardiovascular disordersMitochondrial bioenergeticsExcitation-contraction couplingChannel functionRedox statusMechanistic linkHeart failureArrhythmia suppressionPharmacological interventionsCardiovascular disordersCentral mechanismsDysfunctionArrhythmogenesisEnergy production
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-134PerfusionMitochondria are sources of metabolic sink and arrhythmias
Akar FG, O'Rourke B. Mitochondria are sources of metabolic sink and arrhythmias. Pharmacology & Therapeutics 2011, 131: 287-294. PMID: 21513732, PMCID: PMC3138548, DOI: 10.1016/j.pharmthera.2011.04.005.Peer-Reviewed Original ResearchMeSH KeywordsAnimalsArrhythmias, CardiacCalciumHumansMitochondria, HeartMyocytes, CardiacSignal Transduction
2010
Use‐Dependent Modulation of Myocardial Conduction by a New Class of HERG Agonists: Deal Breaker or Cherry on Top?
AKAR FG. Use‐Dependent Modulation of Myocardial Conduction by a New Class of HERG Agonists: Deal Breaker or Cherry on Top? Journal Of Cardiovascular Electrophysiology 2010, 21: 930-932. PMID: 20367661, DOI: 10.1111/j.1540-8167.2010.01747.x.Commentaries, Editorials and LettersAltered Spatiotemporal Dynamics of the Mitochondrial Membrane Potential in the Hypertrophied Heart
Jin H, Nass RD, Joudrey PJ, Lyon AR, Chemaly ER, Rapti K, Akar FG. Altered Spatiotemporal Dynamics of the Mitochondrial Membrane Potential in the Hypertrophied Heart. Biophysical Journal 2010, 98: 2063-2071. PMID: 20483313, PMCID: PMC2872265, DOI: 10.1016/j.bpj.2010.01.045.Peer-Reviewed Original ResearchLeft ventricular repolarization heterogeneity as an arrhythmic substrate in heart failure.
Akar FG. Left ventricular repolarization heterogeneity as an arrhythmic substrate in heart failure. Minerva Cardioangiologica 2010, 58: 205-12. PMID: 20440250.ChaptersMeSH KeywordsArrhythmias, CardiacCardiomyopathy, DilatedHeart FailureHumansVentricular Function, LeftConceptsHeart failureElectrophysiological substrateSudden cardiac deathCalcium handling proteinsRepolarization gradientsVentricular repolarization heterogeneityHeterogeneous remodelingCardiac deathCardiac functionArrhythmic substrateLeft ventriculeHandling proteinsMuscle layerPathophysiological remodelingRepolarization heterogeneityTissue levelsOrgan system levelArrhythmiasGap junctionsIon channelsOverview of mechanismsSub-cellular changesRemodelingFailureVentricule