title: Transcatheter aortic valve implantation improves carotid and vertebral arterial blood flow in patients with severe aortic stenosis: practical role of orthostatic stress test.
abstract: BACKGROUND
  There are no data on the impact of transcatheter aortic valve implantation (TAVI) on carotid and vertebral arterial blood flow. Our aim was to assess the effects of the orthostatic stress test on carotid and vertebral artery blood flow in patients with severe aortic stenosis (AS) undergoing TAVI.
  
  
  OBJECTIVE
  TAVI may have beneficial effect on carotid and vertebral artery flow in patients with severe aortic stenosis.
  
  
  METHODS
  Thirty carefully selected patients with severe AS undergoing TAVI were enrolled. Peak systolic blood-flow velocity and end-diastolic velocity in the common carotid artery, internal carotid artery, and vertebral artery, as well as spectral analysis of flow pattern with time-averaged maximum velocity (centimeters per second), time-averaged mean velocity (centimeters per second), and flow volume (milliliters per minute) on both sides were measured by duplex ultrasound. Measurements were performed in the supine position and at 1 to 2 minutes after the assumption of the standing position at baseline and 3 months after TAVI.
  
  
  RESULTS
  All duplex ultrasound parameters assessed in the supine position have significantly improved in patients after TAVI as compared to baseline (P < 0.001 for all). The orthostatic stress test induced decrease of carotid and vertebral arterial flow velocities in AS patients before and after TAVI. However, the drop in velocities and flow volume was numerically lower after TAVI.
  
  
  CONCLUSIONS
  TAVI may have some beneficial effect on extracranial artery blood flow by minimalization of its decrease as a response to orthostatic stress.
authors.affiliation: Department of Cardiology, Institute of Cardiology, Jagiellonian University, Krakow, Poland.
authors.forename: Pawel
authors.initials: P
authors.lastname: Kleczyński
authors.affiliation: Department of Cardiology, Institute of Cardiology, Jagiellonian University, Krakow, Poland.
authors.forename: Pawel
authors.initials: P
authors.lastname: Petkow Dimitrow
authors.affiliation: Department of Cardiology, Institute of Cardiology, Jagiellonian University, Krakow, Poland.
authors.forename: Artur
authors.initials: A
authors.lastname: Dziewierz
authors.affiliation: Department of Cardiology, Institute of Cardiology, Jagiellonian University, Krakow, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Surdacki
authors.affiliation: Department of Cardiology, Institute of Cardiology, Jagiellonian University, Krakow, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Dudek
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D001783:Blood Flow Velocity / Q000502:physiology*; D006328:Cardiac Catheterization; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004452:Echocardiography; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D012720:Severity of Illness Index; D013318:Stroke Volume; D013599:Systole; D065467:Transcatheter Aortic Valve Replacement / Q000379:methods*; D018616:Ultrasonography, Doppler, Duplex / Q000379:methods*; D014711:Vertebral Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*
keywords: Doppler ultrasound; aortic stenosis; cerebral blood flow; orthostatic stress; transcatheter aortic valve implantation