title: Ventricular mechanics in the bidirectional glenn procedure and total cavopulmonary connection.
abstract: BACKGROUND
  The time course of ventricular efficiency in Fontan candidates who underwent both the bidirectional Glenn procedure (BDG) and total cavopulmonary connection (TCPC) were analyzed in this study. We previously reported that volume-load reduction of BDG preceding TCPC allowed for any afterload mismatch to be corrected, thereby improving ventricular efficiency after staged TCPC.
  
  
  METHODS
  We measured percent normal systemic ventricular end-diastolic volume (%N-EDV), contractility (end-systolic elastance [Ees]), afterload (effective arterial elastance [Ea]), and ventricular efficiency (ventriculoarterial coupling [Ea/Ees]) based on cardiac catheterization data before and after both BDG and staged TCPC in 30 patients. Ees and Ea were approximated as follows: Ees = mean arterial pressure/minimal ventricular volume, and Ea = maximal ventricular pressure/(maximal ventricular volume - minimal ventricular volume), and Ea/Ees was then calculated. Ventricular volume was divided by body surface area.
  
  
  RESULTS
  The %N-EDV decreased both after BDG and after staged TCPC, thus resulting in an improvement of Ees. Although Ea increased both after BDG and after staged TCPC, Ea decreased during the interval between BDG and staged TCPC. These changes resulted in an improvement in Ea/Ees during the interval period and after staged TCPC, although Ea/Ees worsened after BDG.
  
  
  CONCLUSIONS
  Correction of afterload mismatch during the interval period between BDG and staged TCPC is considered to be one of the most important factors for obtaining excellent clinical results when selecting a staged strategy to treat high-risk Fontan candidates.
authors.affiliation: Department of Cardiovascular Surgery and Pediatric Cardiology, Kyushu Kosei-Nenkin Hospital, Kitakyushu, Japan. tanoue@heart.med.kyushu-u.ac.jp
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Tanoue
authors.forename: Akira
authors.initials: A
authors.lastname: Sese
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Imoto
authors.forename: Kunitaka
authors.initials: K
authors.lastname: Joh
mesh_terms: D000704:Analysis of Variance; D000714:Anastomosis, Surgical; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000379:methods; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D018729:Fontan Procedure / Q000009:adverse effects / Q000379:methods*; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012494:Sampling Studies; D013318:Stroke Volume; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology; D017725:Ventricular Pressure / Q000502:physiology*