title: Mitral leaflet anatomy revisited.
abstract: OBJECTIVE
  The aims of this work were to employ functional imaging capabilities of the Visible Heart laboratory and endoscopic visualization of mitral valves in perfusion-fixed specimens to better characterize variability in mitral valve leaflet anatomy and to provide a method to classify mitral leaflets that varies from the current nomenclature.
  
  
  METHODS
  We gathered functional endoscopic video footage (11 isolated reanimated human hearts) and static endoscopic anatomical images (38 perfusion-fixed specimens) of mitral leaflets. Commissure and cleft locations were charted using Carpentier's accepted description.
  
  
  RESULTS
  All hearts had 2 commissures separating anterior and posterior leaflets. "Standard" clefts separating P1/P2 were found in 66% of hearts (n = 25), and standard clefts separating P2/P3 were present in 71% of hearts (n = 27). "Deviant" clefts occurred in each region of the anterior leaflet (A1, A2, A3), and their relative occurrences were 5%, 8%, and 13% (n = 2, 3, 5), respectively. Deviant clefts were found in posterior leaflets: 13.2% in P1 (n = 5), 32% in P2 (n = 12), and 21% in P3 (n = 8).
  
  
  CONCLUSIONS
  Humans elicit complex and highly variable mitral valve anatomy. We suggest a complementary, yet simple nomenclature to address variation in mitral valve anatomy by describing clefts as either standard or deviant and locating regions in which they occur (A1 to A3 or P1 to P3).
authors.affiliation: Department of Surgery, University of Minnesota, Minneapolis, Minn. 55455, USA.
authors.forename: Jason L
authors.initials: JL
authors.lastname: Quill
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Hill
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Laske
authors.forename: Ottavio
authors.initials: O
authors.lastname: Alfieri
authors.forename: Paul A
authors.initials: PA
authors.lastname: Iaizzo
mesh_terms: D002815:Chordae Tendineae / Q000033:anatomy & histology* / Q000502:physiology; D006321:Heart / Q000033:anatomy & histology; D016027:Heart Transplantation; D006801:Humans; D008943:Mitral Valve / Q000033:anatomy & histology* / Q000502:physiology; D012680:Sensitivity and Specificity