Coronary CirculationNitrogen RadioisotopesDogsRegional Blood FlowOxygen RadioisotopesTomography, Emission-ComputedMicrospheresHeartBlood Flow VelocityMyocardiumCoronary DiseaseDipyridamoleHemodynamicsCoronary VesselsHyperemiaEndocardiumCollateral CirculationAmmoniaMyocardial IschemiaMyocardial ReperfusionOrganotechnetium CompoundsHeart RateMyocardial ContractionMyocardial InfarctionRadioisotopesBlood PressureAdenosineOxygen ConsumptionMyocardial Reperfusion InjuryModels, CardiovascularSwineTime FactorsHeart VentriclesWaterNecrosisStrontium RadioisotopesCerium RadioisotopesVascular ResistanceMyocardial StunningPositron-Emission TomographyMyocardial Perfusion ImagingDobutamineDisease Models, AnimalVasodilator AgentsRestMicrocirculationDiatrizoate MeglumineVasodilationYtterbiumCerebrovascular CirculationEchocardiographyDiatrizoateScandiumSpectrometry, GammaRubidium RadioisotopesRadiopharmaceuticalsFractional Flow Reserve, MyocardialFluorine RadioisotopesVentricular Function, LeftCardiac OutputCerium IsotopesPericardiumContrast MediaVasomotor SystemThalliumBlood VolumePerfusionRadionuclide GeneratorsCoronary StenosisOximesOxygenTomography, Emission-Computed, Single-PhotonImage Processing, Computer-AssistedThallium RadioisotopesXenonLaser-Doppler FlowmetryDeoxyglucosePhysical ExertionPotassium RadioisotopesTechnetium Tc 99m SestamibiTissue SurvivalCoronary Artery DiseaseCoronary AngiographyCardiotonic AgentsRadioisotope Dilution TechniqueAdrenergic beta-1 Receptor AgonistsReproducibility of ResultsReference ValuesCarbon RadioisotopesSulfur HexafluorideNitroglycerinThiosemicarbazonesGated Blood-Pool ImagingSwine, MiniatureFlow CytometryCardiac Pacing, ArtificialFluorocarbonsCardiomyopathy, DilatedFluorodeoxyglucose F18Systole