HeartHeart RateHeart FailureHeart DiseasesHeart TransplantationHeart Defects, CongenitalProton Pump InhibitorsFetal HeartInfusion PumpsIon PumpsHeart ValvesHeart AtriaMyocardiumHeart BlockSodium-Potassium-Exchanging ATPaseInfusion Pumps, ImplantableHeart Arrest, InducedMyocardial ContractionHeart Function TestsMyocytes, CardiacMyocardial IschemiaOuabainTime FactorsHemodynamicsHeart, ArtificialCalcium-Transporting ATPasesCoronary DiseaseCardiac Output, LowVentricular Function, LeftSodiumPerfusionCardiotonic AgentsCardiomyopathy, DilatedMyocardial InfarctionCardiomegalyHeart Failure, SystolicCalciumDogsPotassiumStroke VolumeHeart SeptumRisk FactorsHeart InjuriesEchocardiographyCardiomyopathiesHeart Rate, FetalMyocardial Reperfusion InjuryRheumatic Heart DiseaseHeart ArrestBiological Transport, ActiveVentricular Dysfunction, LeftHeart-Assist DevicesHeart Valve ProsthesisAdrenergic beta-AntagonistsRats, Sprague-DawleyProspective StudiesHeart Failure, DiastolicVentricular RemodelingTreatment OutcomeAmerican Heart AssociationInsulin Infusion SystemsOxygen ConsumptionRats, WistarRabbitsFollow-Up StudiesModels, CardiovascularDisease Models, AnimalCardiac Pacing, ArtificialChronic DiseaseAdenosine TriphosphateAutonomic Nervous SystemHeart Septal DefectsHypoplastic Left Heart SyndromeHeart NeoplasmsNatriuretic Peptide, BrainSarcoplasmic ReticulumExercise TestNational Heart, Lung, and Blood Institute (U.S.)Sympathetic Nervous SystemVentricular PressureKineticsMembrane Transport ProteinsDose-Response Relationship, DrugPlasma Membrane Calcium-Transporting ATPasesSystoleDiastoleIsoproterenolEndocardiumMolecular Sequence DataRNA, MessengerNorepinephrineOmeprazoleHydrogen-Ion ConcentrationRetrospective StudiesBiological MarkersEnzyme InhibitorsDigoxinPropanolaminesHeart Septal Defects, VentricularGuinea Pigs