DobutamineCardiotonic AgentsEchocardiography, StressMyocardial ContractionEchocardiographyAdrenergic beta-AgonistsMyocardial StunningTissue SurvivalExercise TestAdrenergic beta-1 Receptor AgonistsVentricular Function, LeftHemodynamicsMyocardial IschemiaVentricular Dysfunction, LeftHydrazonesCoronary DiseaseCoronary CirculationHeartThallium RadioisotopesTomography, Emission-Computed, Single-PhotonCell SurvivalTechnetium Tc 99m SestamibiAmrinoneMilrinoneSensitivity and SpecificityCoronary AngiographyDipyridamolePredictive Value of TestsHeart RateStroke VolumeMicrobial ViabilityPyridazinesElectrocardiographyEnoximoneMyocardial RevascularizationMyocardiumDogsFetal ViabilityMagnetic Resonance Imaging, CineMyocardial InfarctionSympathomimeticsCardiac OutputSystoleCatecholaminesAtropineFeasibility StudiesOxygen ConsumptionDose-Response Relationship, DrugPropanolaminesTomography, Emission-ComputedObserver VariationAdrenergic beta-AntagonistsRadiopharmaceuticalsProspective StudiesBlood PressureTime FactorsVasodilator AgentsRadionuclide VentriculographyCardiomyopathy, DilatedReceptors, Adrenergic, betaHistory, Early Modern 1451-1600DiastoleEchocardiography, DopplerInfusions, Intravenous