HeartPhenylisopropyladenosineRubidium RadioisotopesVentricular FunctionHeart VentriclesMyocardiumGuinea PigsHeart RateHeart Septal Defects, VentricularHeart FailureVentricular Function, LeftHeart DiseasesVentricular Dysfunction, LeftHeart Defects, CongenitalHeart TransplantationProton Pump InhibitorsHeart AtriaHypertrophy, Left VentricularFetal HeartInfusion PumpsIon PumpsHeart ValvesMyocardial ContractionEchocardiographyHeart BlockHemodynamicsStroke VolumeAtrial Function, LeftHeart Function TestsTime FactorsSodium-Potassium-Exchanging ATPaseInfusion Pumps, ImplantableMyocardial IschemiaHeart Arrest, InducedMyocardial InfarctionDogsMyocytes, CardiacCoronary DiseaseVentricular RemodelingCardiomyopathy, DilatedDiastoleTreatment OutcomeCardiac Output, LowOuabainCardiomyopathiesHeart SeptumHypoplastic Left Heart SyndromeHeart-Assist DevicesCardiotonic AgentsSystoleHeart, ArtificialCalcium-Transporting ATPasesPerfusionProspective StudiesFollow-Up StudiesCardiac Pacing, ArtificialRisk FactorsVentricular PressureMyocardial Reperfusion InjurySodiumHeart Failure, SystolicHeart InjuriesAdrenergic beta-AntagonistsCalciumHeart Valve ProsthesisRats, Sprague-DawleyDisease Models, AnimalPotassiumRheumatic Heart DiseaseModels, CardiovascularRats, WistarCardiomegalyOxygen ConsumptionHeart ArrestHeart Rate, FetalNatriuretic Peptide, BrainHeart Failure, DiastolicEndocardiumChronic DiseaseExercise TestCardiac VolumeCardiac CatheterizationRabbitsBiological Transport, ActivePredictive Value of TestsRetrospective StudiesCardiac Surgical ProceduresHeart AneurysmAmerican Heart AssociationAtrial FibrillationHeart Septal DefectsSympathetic Nervous SystemInsulin Infusion SystemsElectrocardiographyAutonomic Nervous SystemPrognosisDose-Response Relationship, DrugAdenosine TriphosphateBlood Flow VelocitySarcoplasmic Reticulum