DobutamineCardiotonic AgentsEchocardiography, StressMyocardial ContractionEchocardiographyAdrenergic beta-AgonistsExercise TestMyocardial StunningAdrenergic beta-1 Receptor AgonistsVentricular Function, LeftHemodynamicsMyocardial IschemiaHydrazonesVentricular Dysfunction, LeftCoronary DiseaseCoronary CirculationHeartTissue SurvivalTomography, Emission-Computed, Single-PhotonThallium RadioisotopesAmrinoneMilrinoneTechnetium Tc 99m SestamibiCoronary AngiographyHeart RateSensitivity and SpecificityDipyridamolePredictive Value of TestsStroke VolumePyridazinesDogsElectrocardiographyEnoximoneMyocardiumMyocardial RevascularizationMagnetic Resonance Imaging, CineCardiac OutputSympathomimeticsCatecholaminesMyocardial InfarctionInfusions, IntravenousFeasibility StudiesSystoleAtropinePropanolaminesBlood PressureProspective StudiesAdrenergic beta-AntagonistsOxygen ConsumptionTime FactorsObserver VariationVasodilator AgentsRadiopharmaceuticalsReceptors, Adrenergic, betaCardiomyopathy, DilatedTomography, Emission-ComputedRadionuclide VentriculographyHistory, Early Modern 1451-1600DiastoleTreatment OutcomeEchocardiography, DopplerHeart FailureAdrenergic Agonists