Myocardial IschemiaRegional Blood FlowIschemiaBlood Flow VelocityBrain IschemiaMyocardial Reperfusion InjuryCerebrovascular CirculationMyocardiumCoronary CirculationHemodynamicsCoronary DiseaseElectrocardiographyDogsReperfusion InjuryHeartExercise TestBlood PressureMyocardial ReperfusionMyocardial InfarctionLaser-Doppler FlowmetryTime FactorsHeart RateAngina PectorisCardiotonic AgentsDisease Models, AnimalIschemic Preconditioning, MyocardialTomography, Emission-Computed, Single-PhotonRats, Sprague-DawleyCoronary VesselsVascular ResistanceFlow CytometryCollateral CirculationElectrocardiography, AmbulatoryVasodilator AgentsPerfusionCoronary AngiographyReperfusionMicrospheresRats, WistarMyocardial ContractionOxygen ConsumptionMicrocirculationAdenosineOxygenIschemic Attack, TransientVentricular Function, LeftMyocardial Perfusion ImagingDipyridamoleSwineArrhythmias, CardiacBrainPulsatile FlowIschemic PreconditioningMyocardial StunningCreatine KinaseVasodilationRabbitsXenon RadioisotopesAnesthesiaNitric OxideDobutamineWarm IschemiaTomography, Emission-ComputedEchocardiographyHindlimbThallium RadioisotopesHyperemiaLactic AcidCoronary Artery DiseaseNitroglycerinModels, CardiovascularRenal CirculationConstrictionAcute DiseaseProspective StudiesCarbon DioxideIntraoperative ComplicationsLiver CirculationCatsGerbillinaeOrganotechnetium CompoundsMyocytes, CardiacSplanchnic CirculationChest PainLactatesCerebral ArteriesEchocardiography, StressHeart VentriclesLegEndothelium, VascularPredictive Value of TestsDose-Response Relationship, DrugVasoconstrictionAnoxiaCold IschemiaSwine, MiniatureUltrasonography, DopplerCoronary StenosisAnalysis of VarianceRandom Allocation