HeartMyocytes, CardiacMyocardiumMice, TransgenicMice, Inbred C57BLHeart RateHeart FailureFetal HeartHeart DiseasesMyocardial ContractionHeart TransplantationHeart Defects, CongenitalHeart ValvesMyocardial Reperfusion InjuryMice, KnockoutHeart AtriaCardiomegalyMyocardial IschemiaPerfusionAnimals, NewbornCardiotonic AgentsTime FactorsDisease Models, AnimalMice, Inbred StrainsHeart Function TestsMyocardial InfarctionCardiomyopathiesRNA, MessengerAgingGene Expression Regulation, DevelopmentalCells, CulturedHeart BlockVentricular Function, LeftIschemic Preconditioning, MyocardialHemodynamicsCalciumGene ExpressionGene Expression RegulationHeart VentriclesImmunohistochemistryHeart Arrest, InducedIsoproterenolSignal TransductionVentricular RemodelingEchocardiographyCardiomyopathy, DilatedCell DifferentiationIn Situ HybridizationMitochondria, HeartMyocarditisMice, Mutant StrainsStem CellsModels, AnimalTissue DistributionMice, Inbred ICRVentricular MyosinsOrgan SpecificityAction PotentialsVentricular PressureConnexin 43Heart SeptumAge FactorsFibrosisEmbryo, MammalianSarcoplasmic Reticulum Calcium-Transporting ATPasesBlotting, WesternMyocardial ReperfusionMolecular Sequence DataMyosin Heavy ChainsMice, Inbred BALB CAdrenergic beta-AgonistsReverse Transcriptase Polymerase Chain ReactionEndocardiumCoronary DiseaseModels, CardiovascularPhenotypeProtein IsoformsSarcoplasmic ReticulumVentricular Dysfunction, LeftVentricular FunctionOxygen ConsumptionHeterocyclic Compounds, 3-RingHeart Conduction SystemMuscle ProteinsTransgenesSinoatrial NodeExcitation Contraction CouplingStroke VolumeTroponin ISodium-Calcium ExchangerVentricular DysfunctionBase SequenceOrgan Culture TechniquesMyofibrilsCardiac Output, LowEnergy MetabolismVoltage-Sensitive Dye ImagingRats, Sprague-DawleyDose-Response Relationship, DrugTroponin T