Myocytes, CardiacHeartMyocardiumCardiac OutputArrhythmias, CardiacMyoblasts, CardiacMyocardial ContractionHeart VentriclesCardiac Surgical ProceduresCardiomegalyDeath, Sudden, CardiacCells, CulturedModels, CardiovascularHeart DiseasesCardiac Pacing, ArtificialCalciumCardiomyopathiesVentricular FunctionAnimals, NewbornCardiac TamponadeTime FactorsMitochondria, HeartHeart FailureCardiac CatheterizationCardiac ElectrophysiologyRats, Sprague-DawleySarcolemmaHeart Conduction SystemAction PotentialsMyofibrilsHeart ArrestCreatine Kinase, Mitochondrial FormHeart AtriaMyocardial InfarctionSarcomeresVentricular RemodelingCardiotonic AgentsGuinea PigsElectrocardiographyHeart RateMyocardial IschemiaMuscle CellsDogsMembrane PotentialsHemodynamicsRats, WistarCardiac MyosinsCardiac Imaging TechniquesVentricular Function, LeftElectrophysiologyCardiac GlycosidesEchocardiographyIsoproterenolMuscle ProteinsGATA4 Transcription FactorCardiac Output, LowSignal TransductionFetal HeartMyocardial Reperfusion InjuryAtrial Natriuretic FactorOut-of-Hospital Cardiac ArrestChick EmbryoFibrosisCell DifferentiationCardiac VolumeCalcium SignalingHeart TransplantationDisease Models, AnimalTroponin IMice, TransgenicIon ChannelsSodiumPotassium ChannelsImidazolinesCalcium Channels, L-TypeAnti-Arrhythmia AgentsSodium-Calcium ExchangerTroponinHeart Defects, CongenitalRNA, MessengerPericardiumSodium ChannelsRyanodine Receptor Calcium Release ChannelPotassiumStroke VolumeCalcium Channel BlockersKineticsRabbitsBlood PressureCardiac Resynchronization TherapyHeart Function TestsMice, Inbred C57BLAtrial FunctionTroponin TCell SizeGene Expression RegulationFibroblastsApoptosisTissue EngineeringPatch-Clamp Techniques