title: The peak to mean pressure decrease ratio: a new method of assessing aortic stenosis.
abstract: BACKGROUND
  The ratio of peak to mean pressure decrease is a new measure of transaortic continuous waveform shape that could be useful for grading aortic stenosis.
  
  
  METHODS
  We retrospectively analyzed echocardiograms in 163 patients with all grades of aortic stenosis as assessed by the continuity equation.
  
  
  RESULTS
  The peak to mean pressure decrease ratio was 1.75 (0.14) in mild stenosis, 1.66 (0.13) in moderate stenosis, 1.56 (0.10) in severe stenosis, and 1.57 (0.07) in severe aortic stenosis with left ventricular ejection fraction less than 40%. Receiver operating characteristic curve analysis showed that a threshold of less than 1.50 gave a specificity of 94% against continuity area whereas a ratio less than 1.75 gave a sensitivity of 96%.
  
  
  CONCLUSIONS
  The peak to mean pressure decrease ratio is a simple and quick cue to the likelihood of severe aortic stenosis in patients with low left ventricular ejection fraction when transaortic pressure decreases appear only moderate.
authors.affiliation: Guy's and St Thomas' Hospitals, London, United Kingdom. jboydchambers@aol.com
authors.forename: John
authors.initials: J
authors.lastname: Chambers
authors.forename: Ronak
authors.initials: R
authors.lastname: Rajani
authors.forename: Matthew
authors.initials: M
authors.lastname: Hankins
authors.forename: Robert
authors.initials: R
authors.lastname: Cook
mesh_terms: D000368:Aged; D001024:Aortic Valve Stenosis / Q000145:classification* / Q000150:complications / Q000000981:diagnostic imaging*; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000379:methods; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018487:Ventricular Dysfunction, Left / Q000145:classification* / Q000000981:diagnostic imaging* / Q000209:etiology