HeartCardiac OutputMyocardiumOxygen ConsumptionCoronary CirculationMyocytes, CardiacMyocardial ContractionHemodynamicsHeart RatePerfusionVentricular Function, LeftDogsPhosphocreatineAdrenergic beta-AntagonistsMitochondria, HeartEnergy MetabolismDobutamineTomography, Emission-ComputedBlood PressureArrhythmias, CardiacCardiac Surgical ProceduresDeath, Sudden, CardiacFatty AcidsAdenosine TriphosphateWorkGlucoseCardiomegalyCardiac Pacing, ArtificialCardiac TamponadeHeart DiseasesCardiac CatheterizationHeart VentriclesHeart ArrestMyoblasts, CardiacHeart FailureCardiomyopathiesTime FactorsElectrocardiographyCardiac MyosinsCardiac Imaging TechniquesCardiac GlycosidesEchocardiographyCardiac Output, LowOut-of-Hospital Cardiac ArrestMyocardial InfarctionCardiac VolumeVentricular RemodelingHeart TransplantationTroponin IHeart Defects, CongenitalStroke VolumeHeart Function TestsCardiac Resynchronization TherapyTroponin THeart Conduction SystemCardiopulmonary ResuscitationHeart NeoplasmsCardiac Care FacilitiesCardiotonic AgentsCardiomyopathy, DilatedVentricular Dysfunction, LeftMyocardial IschemiaWork Schedule ToleranceRats, Sprague-DawleyProspective StudiesTreatment OutcomeModels, CardiovascularCardiac ElectrophysiologyCalciumFibrosisWork Capacity EvaluationFetal HeartCells, CulturedDisease Models, AnimalHeart AtriaVentricular FunctionRisk FactorsReturn to WorkHeart InjuriesFollow-Up StudiesCardiopulmonary BypassMice, TransgenicTroponinRetrospective StudiesHypertrophy, Left VentricularMyocarditisRats, WistarSarcomeresIsoproterenolMuscle ProteinsPredictive Value of TestsAtrial Natriuretic FactorMice, Inbred C57BLBiological MarkersHeart ValvesSignal TransductionPericardiumPacemaker, ArtificialAnimals, NewbornRisk Assessment