Blood Flow VelocityCoronary CirculationCoronary VesselsDogsUltrasonography, Doppler, TranscranialMiddle Cerebral ArteryRegional Blood FlowCerebrovascular CirculationCerebral ArteriesUltrasonography, DopplerMephenterminePulsatile FlowCoronary Artery DiseaseHypocapniaBlood PressureCoronary AngiographyArteriesCoronary Artery BypassUterusEphedrineOphthalmic ArteryFetal Growth RetardationUltrasonography, Doppler, ColorUltrasonography, Doppler, PulsedCarbon DioxideHemodynamicsVascular ResistanceUmbilical ArteriesHomeostasisPregnancyMesenteric Artery, SuperiorCoronary DiseaseFemoral ArteryCoronary StenosisAngioplasty, Balloon, CoronaryLaser-Doppler FlowmetryCarotid ArteriesVasodilationUltrasonographyVasodilator AgentsPulmonary ArteryRheologyUltrasonography, PrenatalRetinal ArteryHeart RateTime FactorsProspective StudiesBronchial ArteriesHyperemiaCarotid Artery, InternalMicrocirculationMyocardial InfarctionCircle of WillisSplanchnic CirculationEchocardiography, DopplerGestational AgeReference ValuesPlacental CirculationBrachial ArteryNitroglycerinVasoconstrictionEchoencephalographyCoronary VasospasmTreatment OutcomeHeart Rate, FetalRadial ArteryCoronary AneurysmCardiac OutputCiliary ArteriesUterine ArteryOxygenMesenteric ArteriesElectrocardiographyRenal ArteryFollow-Up StudiesRisk FactorsDiastoleCoronary Artery Bypass, Off-PumpPredictive Value of TestsAnalysis of VarianceMyocardial IschemiaSwineEchocardiographyModels, CardiovascularStentsBasilar ArteryHyperventilationOxygen ConsumptionUltrasonography, InterventionalCeliac ArteryCarotid Artery, ExternalCollateral CirculationCoronary ThrombosisCardiac CatheterizationCarotid Artery, CommonMammary ArteriesEndothelium, VascularUltrasonography, Doppler, DuplexHeartCoronary Occlusion