title: Characterization of human coronary sinus valves by direct visualization during biventricular pacemaker implantation.
abstract: BACKGROUND
  The precise reasons for failure to cannulate the coronary sinus during biventricular device implantation are unknown. Visualization of the coronary sinus ostium during electrophysiology procedures may enhance understanding of how unusual anatomy can affect successful cannulation of the coronary sinus.
  
  
  OBJECTIVE
  The aim of this study was to describe the morphology of valves at the coronary sinus ostium (CSO) visualized directly with an illuminated fiberoptic endoscope during implantation of biventricular devices.
  
  
  METHODS
  The coronary sinus anatomy of one hundred consecutive patients undergoing implantation of biventricular devices was investigated using a fiberoptic endocardial visualization catheter (EVC).
  
  
  RESULTS
  The CSO was clearly visualized in 98 patients using the EVC. A Thebesian valve was seen in 54% of these. Almost all Thebesian valves were positioned at the inferior (61%) or posterior (33%) aspect of the CSO. Only six patients had Thebesian valves that covered more than 70% of the CSO, but all were successfully implanted with a transvenous left ventricular pacing lead after cannulating the coronary sinus under direct visualization.
  
  
  CONCLUSIONS
  Over half of patients undergoing biventricular device implantation have identifiable Thebesian valves. Even valves covering the majority of the ostial area may be traversed using direct visualization and modern catheterization techniques.
authors.affiliation: Cardiac Arrhythmia Service, Stanford University Medical Center, Stanford, California, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Anh
authors.forename: Christian S
authors.initials: CS
authors.lastname: Eversull
authors.forename: Henry A
authors.initials: HA
authors.lastname: Chen
authors.forename: Pirooz
authors.initials: P
authors.lastname: Mofrad
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Mourlas
authors.forename: R Hardwin
authors.initials: RH
authors.lastname: Mead
authors.forename: Paul C
authors.initials: PC
authors.lastname: Zei
authors.forename: Henry H
authors.initials: HH
authors.lastname: Hsia
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wang
authors.forename: Amin
authors.initials: A
authors.lastname: Al-Ahmad
mesh_terms: D000368:Aged; D020677:Angioscopes; D017546:Angioscopy / Q000379:methods*; D002404:Catheterization / Q000295:instrumentation; D004867:Equipment Design; D005260:Female; D005336:Fiber Optic Technology; D006333:Heart Failure / Q000628:therapy*; D006351:Heart Valves; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial