StrokeStroke VolumeCardiac OutputBlood VolumeHemodynamicsBrain IschemiaBlood PressureHeart RateCerebrovascular DisordersFluid TherapyCardiography, ImpedanceThermodilutionVentricular Function, LeftVascular ResistanceTime FactorsCardiac VolumeHypovolemiaHeartProspective StudiesMagnetic Resonance ImagingVentricular Function, RightPlasma VolumeCardiovascular Physiological PhenomenaHeart VentriclesCerebral HemorrhageBlood Flow VelocityMyocardial ContractionCerebral InfarctionCentral Venous PressureRisk FactorsEchocardiography, DopplerTreatment OutcomeVentricular FunctionOxygen ConsumptionSystoleHeart Function TestsMonitoring, PhysiologicIschemic Attack, TransientHead-Down TiltSupine PositionBlood Volume DeterminationDogsCerebral AqueductPhysical ExertionEchocardiographyFollow-Up StudiesMonitoring, IntraoperativeReproducibility of ResultsExercise TestDiastoleLower Body Negative PressurePulmonary Wedge PressureLung Volume MeasurementsAcute DiseasePulseRespirationCardiovascular DeconditioningPostureRecovery of FunctionExerciseCineangiographyEchocardiography, Three-DimensionalSeverity of Illness IndexCatheterization, Swan-GanzTomography, X-Ray ComputedPredictive Value of TestsBed RestBrainMagnetic Resonance Imaging, CineFibrinolytic AgentsComplianceParesisStroke, LacunarPlasma SubstitutesBrain InfarctionHeart FailureTissue Plasminogen ActivatorCardiac CatheterizationRegional Blood FlowCohort StudiesFluid ShiftsObserver VariationHypertensionMitral Valve InsufficiencyCardiovascular SystemEchocardiography, TransesophagealOrthostatic IntoleranceRetrospective StudiesModels, CardiovascularPulmonary CirculationErythrocyte VolumeInfarction, Middle Cerebral ArteryRestFetal HeartTilt-Table TestHypotension, OrthostaticImage Processing, Computer-AssistedThrombolytic TherapyVentricular PressureEchocardiography, Doppler, Color