title: Anatomical variations of the coronary sinus valve (Thebesian valve): implications for electrocardiological procedures.
abstract: OBJECTIVE
  The Thebesian valve (TV) can be a significant obstacle to coronary sinus (CS) cannulation. The aim of this study was to evaluate the characteristic features of the CS valve--TV anatomy. In particular, emphasis was placed on identifying specific structures of the TV that could potentially complicate CS cannulation.
  
  
  RESULTS
  We examined 273 autopsied human hearts. The height of the TV and the diameter of the CS were measured. The valves were classified according to their shape into five types: remnant, semilunar, fold, cord, and mesh and fenestrated. The mean transverse CS ostium (CSO) diameter was 12.2 ± 3.5 mm. The TV was present in 224 (82.1%) cases. The most common type of TV was semilunar: 32.6%; followed by remnant: 25.5%; fold: 17.4%; cord: 14.3%; and lastly mesh and fenestrated: 10.3%. The mean TV height for remnant-semilunar-fold types was 5.8 ± 3.0 mm. In seven cases, the present TV (2.6%) covered the entire orifice of the CS. Hearts with larger CSO diameter had lower TV height (P < 0.001).
  
  
  CONCLUSIONS
  We propose a new classification of the TV shapes based on the largest sample to date. We assessed that only in 2.6% of all 273 cases the presence of an obstructive TV can cause unsuccessful cannulation. The height of the TV was inversely correlated to the CSO diameter (r = -0.33; P < 0.001).
authors.affiliation: Department of Anatomy, Jagiellonian University Medical College, Kopernika 12, Kraków 31-034, Poland mateusz_holda@onet.eu.
authors.forename: Mateusz K
authors.initials: MK
authors.lastname: Hołda
authors.affiliation: Department of Anatomy, Jagiellonian University Medical College, Kopernika 12, Kraków 31-034, Poland.
authors.forename: Wiesława
authors.initials: W
authors.lastname: Klimek-Piotrowska
authors.affiliation: Department of Anatomy, Jagiellonian University Medical College, Kopernika 12, Kraków 31-034, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Koziej
authors.affiliation: Department of Anatomy, Jagiellonian University Medical College, Kopernika 12, Kraków 31-034, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Mazur
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D063405:Anatomic Variation; D001344:Autopsy; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D054326:Coronary Sinus / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D055422:Venous Valves / Q000033:anatomy & histology*; D055815:Young Adult
keywords: Cardiac resynchronization therapy; Coronary sinus cannulation; Thebesian valve shape