Cell LineageMyocytes, CardiacHeartMyocardiumCell DifferentiationCardiac OutputArrhythmias, CardiacCells, CulturedMyoblasts, CardiacMyocardial ContractionHeart VentriclesStem CellsCardiac Surgical ProceduresCardiomegalyPhylogenyDeath, Sudden, CardiacReplication OriginGene Expression Regulation, DevelopmentalMice, TransgenicMolecular Sequence DataTime FactorsModels, CardiovascularHeart DiseasesAnimals, NewbornTranscription FactorsSignal TransductionCalciumCardiac Pacing, ArtificialMice, Inbred C57BLBase SequenceCardiomyopathiesVentricular FunctionEmbryonic Stem CellsCardiac TamponadeRats, Sprague-DawleyGene Expression RegulationPhenotypeMice, KnockoutEvolution, MolecularModels, BiologicalRNA, MessengerCell LineMitochondria, HeartHomeodomain ProteinsHeart FailureMesodermCardiac CatheterizationCardiac ElectrophysiologyHeart Conduction SystemSarcolemmaAction PotentialsChick EmbryoHeart AtriaGene ExpressionMyofibrilsImmunohistochemistryHeart ArrestMyocardial InfarctionHematopoietic Stem CellsCreatine Kinase, Mitochondrial FormSarcomeresBiological EvolutionVentricular RemodelingMutationEmbryo, MammalianDogsCardiotonic AgentsGuinea PigsIn Situ HybridizationGATA4 Transcription FactorElectrocardiographyDNA-Binding ProteinsReverse Transcriptase Polymerase Chain ReactionHeart RateRats, WistarMuscle CellsMuscle ProteinsMyocardial IschemiaMembrane PotentialsDisease Models, AnimalBiological MarkersAmino Acid SequenceFetal HeartHemodynamicsCardiac MyosinsFlow CytometryApoptosisElectrophysiologyCell SeparationVentricular Function, LeftCardiac Imaging TechniquesCell ProliferationRegenerationCell DivisionThymus GlandCardiac GlycosidesSequence Analysis, DNAEchocardiographyGreen Fluorescent ProteinsIsoproterenol