title: Ejection fraction velocity ratio as an indicator of aortic stenosis severity.
abstract: BACKGROUND
  Despite the widespread use of the continuity equation in the estimation of aortic valve area (AVA) in patients with aortic stenosis, it is subject to errors, time consuming, and can be technically demanding. As such, simpler methods of assessing aortic stenosis severity have been pursued.
  
  
  METHODS
  The ejection fraction velocity ratio [EFVR = ejection fraction (%) / maximal aortic velocity (m/sec)] was compared to AVA determined with the continuity equation in 857 patients with aortic stenosis and varying degrees of LV systolic dysfunction. Severe aortic stenosis was defined as an AVA < 1.0 cm2.
  
  
  RESULTS
  There was good to excellent correlation between our index and aortic valve area (P < 0.001 for each ejection fraction subgroup). Receiver operating characteristic analysis showed that the EFVR functioned well with areas under the curve between 0.893 and 0.938.
  
  
  CONCLUSIONS
  The EFVR is a simple noninvasive method for screening patients for an AVA of 1.0 cm2. It could be used as a screening test or in lieu of the continuity equation particularly when there is problematic measurement of either the LVOT diameter or velocity.
authors.affiliation: The Department of Medicine, Division of Cardiology, London Health Sciences Centre, Victoria Campus, University of Western Ontario, London, Ontario, Canada.
authors.forename: A M
authors.initials: AM
authors.lastname: Al-Ghamdi
authors.forename: L J
authors.initials: LJ
authors.lastname: Melendez
authors.forename: D
authors.initials: D
authors.lastname: Massel
mesh_terms: D000368:Aged; D000465:Algorithms; D001021:Aortic Valve / Q000000981:diagnostic imaging; D001024:Aortic Valve Stenosis / Q000145:classification* / Q000000981:diagnostic imaging; D019540:Area Under Curve; D001783:Blood Flow Velocity / Q000502:physiology*; D015331:Cohort Studies; D015150:Echocardiography, Doppler; D018618:Echocardiography, Doppler, Color; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D006801:Humans; D008297:Male; D012372:ROC Curve; D012189:Retrospective Studies; D013318:Stroke Volume / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging