Myocytes, CardiacCell DifferentiationMyocardiumHeartCells, CulturedHeart VentriclesMyocardial ContractionCardiac OutputCardiomegalyArrhythmias, CardiacCalciumCardiac Surgical ProceduresDeath, Sudden, CardiacAnimals, NewbornRats, Sprague-DawleyMuscle CellsSignal TransductionTime FactorsRNA, MessengerIsoproterenolCalcium Channels, L-TypeCardiac Pacing, ArtificialHeart DiseasesVentricular FunctionGene Expression RegulationCardiomyopathiesRats, WistarMice, TransgenicSodium-Calcium ExchangerTranscription FactorsCardiac TamponadeHeart FailureSarcolemmaStem CellsMice, KnockoutMice, Inbred C57BLSarcomeresHeart AtriaCalcium SignalingGene Expression Regulation, DevelopmentalPatch-Clamp TechniquesMyoblasts, CardiacCardiac CatheterizationCell LineGuinea PigsMuscle ProteinsModels, CardiovascularMitochondria, HeartGene ExpressionCell SizeCardiac MyosinsMolecular Sequence DataAdrenergic beta-AgonistsAction PotentialsCardiotonic AgentsHeart ArrestMembrane PotentialsDogsTroponin IMyocardial InfarctionGATA4 Transcription FactorPhosphorylationReceptors, Adrenergic, betaVentricular RemodelingElectrocardiographySarcoplasmic ReticulumReverse Transcriptase Polymerase Chain ReactionImmunohistochemistryMyocardial IschemiaBlotting, WesternHeart RateSarcoplasmic Reticulum Calcium-Transporting ATPasesDNA-Binding ProteinsAtrial Natriuretic FactorCell LineageRabbitsEchocardiographyPotassium ChannelsApoptosisCardiac Output, LowCell DivisionEmbryonic Stem CellsBase SequenceTransfectionMyosin Heavy ChainsRyanodine Receptor Calcium Release ChannelPhenotypeCell ProliferationCardiac GlycosidesDisease Models, AnimalHemodynamicsCardiomyopathy, DilatedCardiac Imaging TechniquesDose-Response Relationship, DrugEnzyme InhibitorsVentricular Function, LeftHeart TransplantationSex DifferentiationTranscription, GeneticElectrophysiology