Myocytes, CardiacMyocardiumCells, CulturedResearch PersonnelHeartAnimals, NewbornCardiomegalyMutationMyocardial ContractionRats, Sprague-DawleyHeart VentriclesPhenotypeRats, WistarMolecular Sequence DataCalciumSignal TransductionMice, TransgenicMitochondria, HeartBiomedical ResearchCell DifferentiationMice, KnockoutMutation, MissenseApoptosisPedigreeBase SequenceEmbryonic Stem CellsMyocardial Reperfusion InjuryCardiotonic AgentsSarcomeresMice, Inbred C57BLRNA, MessengerDisease Models, AnimalCell SizeGATA4 Transcription FactorCalcium Channels, L-TypeAmino Acid SequenceIsoproterenolTime FactorsGene Expression RegulationHypertrophyConnexin 43Muscle CellsTranscription FactorsMuscle ProteinsGene ExpressionCell LineCalcium SignalingReverse Transcriptase Polymerase Chain ReactionSarcoplasmic Reticulum Calcium-Transporting ATPasesResearchEthics, ResearchSarcolemmaBlotting, WesternCardiac MyosinsHeterozygoteSodium-Calcium ExchangerExonsCardiomyopathiesMyocardial IschemiaMyoblasts, CardiacInternetDNA Mutational AnalysisPhosphorylationCell SurvivalGene TargetingVentricular MyosinsVentricular RemodelingHomozygoteAdrenergic beta-AgonistsInduced Pluripotent Stem CellsStem Cells