title: Functional analysis of the anatomical right ventricular components: should assessment of right ventricular function after repair of tetralogy of Fallot be refined?
abstract: OBJECTIVE
  Follow-up after tetralogy of Fallot (ToF) repair is directed to detect timely right ventricular (RV) dysfunction by following pulmonary regurgitation and global RV size, with little attention for the effective contribution of regional RV dysfunction. This study investigates the contribution of regional RV dysfunction on exercise capacity after ToF repair.
  
  
  METHODS
  Forty-two patients were investigated with cardiac magnetic resonance imaging for regional RV dysfunction in relation to global RV function by functional quantification of the sinus and outflow part of the RV. The impact of regional and global RV dysfunction on clinical status was studied by exercise testing.
  
  
  RESULTS
  Global RV function was lower than sinus function (ejection fraction (EF) 52±12% vs 58±10%, P<0.001), attributable to the adverse influence of right ventricular outflow tract (RVOT) dysfunction (EF 34±17%). Percent predicted peak VO2 correlated better with the RV sinus ejection fraction compared with the global RV ejection fraction (r=0.51, P=0.001 vs r=0.44, P=0.004). Multivariate analysis revealed the EF of RV sinus (β=0.34, 95% CI 0.07-0.61, P=0.013) and the extent of RVOT akinesia (β=-0.28, 95% CI -0.50; -0.06, P=0.015) as significant determinants of exercise capacity. Impaired exercise performance occurred in 43% of the patients, and was independently determined by the type of repair (transventricular vs transatrial: OR 6.0, 95% CI 1.31-17.3, P=0.02) by associating greater sinus and RVOT dysfunction.
  
  
  CONCLUSIONS
  Functional analysis of the RV components shows that exercise capacity after repair of ToF is better predicted by systolic function of the RV sinus as the extent of RVOT dysfunction commonly leads to underestimation of global RV function. This method of differential quantification of regional RV function might be more appropriate than assessment of global RV function during the long-term follow-up of repaired ToF patients.
authors.affiliation: Department of Cardiac Surgery, University Hospital of Ghent, Ghent, Belgium.
authors.forename: Thierry
authors.initials: T
authors.lastname: Bove
authors.forename: Kristof
authors.initials: K
authors.lastname: Vandekerckhove
authors.forename: Daniel
authors.initials: D
authors.lastname: Devos
authors.forename: Joseph
authors.initials: J
authors.lastname: Panzer
authors.forename: Katya
authors.initials: K
authors.lastname: De Groote
authors.forename: Hans
authors.initials: H
authors.lastname: De Wilde
authors.forename: Daniel
authors.initials: D
authors.lastname: De Wolf
authors.forename: Julie
authors.initials: J
authors.lastname: De Backer
authors.forename: Laurent
authors.initials: L
authors.lastname: Demulier
authors.forename: Katrien
authors.initials: K
authors.lastname: François
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013771:Tetralogy of Fallot / Q000601:surgery*; D016278:Ventricular Function, Right / Q000502:physiology; D055815:Young Adult
keywords: Congenital heart disease; Right ventricular function; Tetralogy of Fallot