title: A simple different method to use proximal isovelocity surface area (PISA) for measuring mitral valve area.
abstract: BACKGROUND
  Angle-correction is an important limiting factor for using proximal isovelocity surface area (PISA) method in measuring mitral valve area (MVA). In this study, we derived a novel formula, which simplifies the angle-correction, and tested its use in patients with mitral stenosis (MS).
  
  
  METHODS
  The study included 30 MS patients without concomitant aortic or mitral regurgitation. We used mathematical equations and established a relation between the angle and its corresponding border, 'a', by using linear regression analysis. It was found that MVA is equal to [(1.11*a2 + 0.95)* r2 (Val/Vmax)]. We compared this formula with plain angle-corrected and solid angle-corrected PISA methods, planimetry (reference method) and pressure-half time method by linear regression analysis.
  
  
  RESULTS
  All methods were in significant relation with the reference method, two-dimensional planimetry. We found that there is a good relation between our method and planimetry (r = 0.79, p < 0.001), pressure half-time method (r = 0.85, p < 0.001), angle-corrected PISA method (r = 0.99, p < 0.001), and solid angle-corrected PISA method (r = 0.88, p < 0.001). The time duration of the new method was shorter (p < 0.001).
  
  
  CONCLUSIONS
  Our method is an easy way for applying angle-corrected PISA method to mitral valve area measurement in patients with mitral stenosis. Absence of the need for estimating the angle is the major advantage.
authors.affiliation: Department of Cardiology, Gulhane Military Medical Academy, Etlik, Ankara, Turkey. muzun1@yahoo.com
authors.forename: Mehmet
authors.initials: M
authors.lastname: Uzun
authors.forename: Oben
authors.initials: O
authors.lastname: Baysan
authors.forename: Kursad
authors.initials: K
authors.lastname: Erinc
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ozkan
authors.forename: Cemal
authors.initials: C
authors.lastname: Sag
authors.forename: Celal
authors.initials: C
authors.lastname: Genc
authors.forename: Hayrettin
authors.initials: H
authors.lastname: Karaeren
authors.forename: Mehmet
authors.initials: M
authors.lastname: Yokusoglu
authors.forename: Ersoy
authors.initials: E
authors.lastname: Isik
mesh_terms: D000328:Adult; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000473:pathology*; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging / Q000473:pathology*; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results