Basilar ArteryVertebrobasilar InsufficiencyCoronary VesselsCoronary Artery DiseaseVertebral ArteryCoronary Artery BypassArteriesPosterior Cerebral ArteryCoronary AngiographyInfarction, Posterior Cerebral ArteryCoronary CirculationCerebral ArteriesCerebral AngiographyIntracranial AneurysmMagnetic Resonance AngiographyBrain Stem InfarctionsCoronary DiseaseCoronary StenosisSubarachnoid HemorrhageAngioplasty, Balloon, CoronaryPulmonary ArteryCerebrovascular CirculationTomography, X-Ray ComputedBrain InfarctionAneurysm, RupturedCerebral InfarctionTreatment OutcomeCarotid ArteriesIntracranial ArteriosclerosisCarotid Artery, InternalEmbolization, TherapeuticStrokeFemoral ArteryMoyamoya DiseaseVertebral Artery DissectionRisk FactorsFollow-Up StudiesRenal ArteryMesenteric ArteriesStentsVasodilationMyocardial InfarctionMammary ArteriesCoronary VasospasmProspective StudiesRetrospective StudiesBrain IschemiaAngiographyAnterior Cerebral ArteryMagnetic Resonance ImagingDogsArterial Occlusive DiseasesRadial ArteryVasodilator AgentsVasoconstrictionCoronary Artery Bypass, Off-PumpTime FactorsCoronary AneurysmUltrasonography, Doppler, TranscranialConstriction, PathologicPredictive Value of TestsIschemic Attack, TransientIliac ArteryMuscle, Smooth, VascularAngiography, Digital SubtractionIntracranial EmbolismEndothelium, VascularAneurysm, DissectingCarotid Artery DiseasesCoronary ThrombosisCerebrovascular DisordersHemodynamicsSubclavian ArteryElectrocardiographyCalcinosisAcute DiseaseMyocardial IschemiaCoronary OcclusionBrachial ArteryCoronary RestenosisSwineRecurrenceCerebral RevascularizationCollateral CirculationThoracic ArteriesNitroglycerinVasospasm, IntracranialCarotid Artery, CommonSplenic ArteryBlood PressureRegistriesCoronary Vessel AnomaliesUltrasonography, InterventionalMiddle Cerebral ArteryHepatic ArteryVasoconstrictor AgentsAcetylcholineCardiac CatheterizationBlood CirculationRegional Blood Flow