Mesenteric ArteriesMesenteric Artery, SuperiorMesenteric Artery, InferiorIntestinal ObstructionArteriesAirway ObstructionCarotid StenosisAortic Valve StenosisUreteral ObstructionCoronary StenosisMesenteric Vascular OcclusionConstriction, PathologicCeliac ArteryTracheal StenosisSpinal StenosisSuperior Mesenteric Artery SyndromePulmonary ArteryRenal ArteryDuodenal ObstructionCarotid ArteriesPyloric StenosisCerebral ArteriesFemoral ArteryPulmonary Valve StenosisMitral Valve StenosisVasodilationMuscle, Smooth, VascularVasoconstrictionCarotid Artery, InternalRenal Artery ObstructionStentsSplanchnic CirculationBasilar ArteryTreatment OutcomeTomography, X-Ray ComputedIliac ArteryAngiographyMesenteric VeinsVasodilator AgentsUrinary Bladder Neck ObstructionBiological FactorsVasoconstrictor AgentsUrethral ObstructionNasal ObstructionVentricular Outflow ObstructionCoronary Artery BypassCoronary AngiographyArterial Occlusive DiseasesGastric Outlet ObstructionCoronary VesselsVertebral ArteryCarotid Artery DiseasesSplenic ArteryEndothelium, VascularTime FactorsAngioplasty, BalloonHepatic ArteryFollow-Up StudiesNorepinephrineRadial ArterySubclavian ArteryUltrasonography, Doppler, DuplexBlood PressureMammary ArteriesRats, WistarRetrospective StudiesMagnetic Resonance AngiographyPhenylephrineCatheterizationDuodenostomyMyographyProspective StudiesAortic Stenosis, SubvalvularAcetylcholineCarotid Artery, CommonLacrimal Duct ObstructionPostoperative ComplicationsRats, Sprague-DawleyHemodynamicsVena Cava, SuperiorSeverity of Illness IndexRegional Blood FlowUltrasonography, DopplerMuscle ContractionDogsCoronary DiseaseBrachial ArteryRats, Inbred WKYMuscle RelaxationNitric OxideDose-Response Relationship, DrugVascular PatencyAngiography, Digital SubtractionAneurysmBlood Flow VelocityEndarterectomy, CarotidAortic Stenosis, SupravalvularSensitivity and SpecificityPredictive Value of TestsAngioplasty