Subarachnoid HemorrhageVasospasm, IntracranialCoronary VasospasmBasilar ArteryIschemic Attack, TransientCerebral AngiographyCisterna MagnaIntracranial AneurysmSpasmPapaverineAneurysm, RupturedCerebral ArteriesUltrasonography, Doppler, TranscranialErgonovineNimodipineNicardipineCerebrovascular CirculationVasoconstrictionAngiography, Digital SubtractionPregnatrienesVasodilator AgentsAngina Pectoris, VariantInfusions, Intra-ArterialMiddle Cerebral ArteryTomography, X-Ray ComputedDogsSubarachnoid SpaceRupture, SpontaneousInjections, Intra-ArterialDioxanesPerfusion ImagingVentriculostomy1-(5-Isoquinolinesulfonyl)-2-MethylpiperazineDisease Models, AnimalRaynaud DiseaseBrain IschemiaTreatment OutcomeFormamidesBlood Flow Velocity