Myocytes, CardiacMyocardiumHeartHeart VentriclesMyocardial ContractionCardiac OutputCalciumArrhythmias, CardiacCardiomegalyCells, CulturedCardiac Surgical ProceduresMuscle CellsDeath, Sudden, CardiacVentricular FunctionRats, Sprague-DawleyTime FactorsPatch-Clamp TechniquesCalcium Channels, L-TypeIschemic Attack, TransientCalcium SignalingAction PotentialsSodium-Calcium ExchangerHeart AtriaCardiac Pacing, ArtificialGuinea PigsMembrane PotentialsIsoproterenolHeart DiseasesAnimals, NewbornPotassium ChannelsHeart FailureRats, WistarCardiac TamponadeSarcoplasmic ReticulumCardiomyopathiesSarcolemmaCardiac CatheterizationElectrophysiologyDogsCalcium ChannelsAdrenergic beta-AgonistsModels, CardiovascularCaffeineCardiotonic AgentsRabbitsElectrocardiographyCardiac MyosinsHeart ArrestSarcoplasmic Reticulum Calcium-Transporting ATPasesSarcomeresHeart RateCell SizeMyoblasts, CardiacMyocardial InfarctionRyanodine Receptor Calcium Release ChannelSignal TransductionCardiac Output, LowTroponin ICardiac GlycosidesRNA, MessengerVentricular RemodelingEchocardiographyHemodynamicsDose-Response Relationship, DrugMyocardial IschemiaReceptors, Adrenergic, betaHeart Conduction SystemKineticsVentricular Function, LeftMitochondria, HeartDisease Models, AnimalMuscle ProteinsCardiac Imaging TechniquesPericardiumElectric ConductivityMice, TransgenicSodium ChannelsPotassiumHeart TransplantationCardiomyopathy, DilatedMice, Inbred C57BLSodiumExcitation Contraction CouplingAtrial Natriuretic FactorCardiac ElectrophysiologyGene Expression RegulationOut-of-Hospital Cardiac ArrestMice, KnockoutEnzyme InhibitorsBlood PressureAnti-Arrhythmia AgentsCalcium Channel BlockersEndocardiumElectric StimulationPhosphorylationCardiac VolumeMolecular Sequence DataIon Channel GatingMicroscopy, ConfocalPotassium Channels, Voltage-Gated