title: Refining the assessment of pulmonary regurgitation in adults after tetralogy of Fallot repair: should we be measuring regurgitant fraction or regurgitant volume?
abstract: OBJECTIVE
  Pulmonary regurgitation (PR) is an important determinant of outcome after tetralogy of Fallot (TOF) repair. The physiologic impact of PR on the right ventricle remains incompletely understood. We hypothesized that a volumetric expression of PR would be a better measure of ventricular preload and a more accurate reflection of degree of insufficiency.
  
  
  RESULTS
  Patients (n = 64) with magnetic resonance imaging after TOF repair were identified. PR was quantified using: (i) phase contrast (PC) analysis of main pulmonary artery flow and (ii) differential right and left ventricular stroke volumes. PR was expressed as a volume (PR(volume)) and percentage of total forward flow (PR(fraction)). The median PC(PR volume) was 19 mL/m(2) (range 0-63 mL/m(2)) and PC(PR fraction) was 29% (range 0-58%). PR(fraction) was found to be highly variable in terms of absolute PR(volume). In those with significant PR, PR(volume) was better than PR(fraction) for the identification of severe RV dilation (receiver-operator curve area: 0.83 vs. 0.71, P = 0.003). PR(volume) using PC analysis was better at differentiating moderate from severe RV dilation (P = 0.005) as compared with PR(fraction) (P = 0.064).
  
  
  CONCLUSIONS
  PR(volume) and PR(fraction) are not interchangeable. PR(volume) may be a more accurate reflection of RV preload and may better represent physiologically significant PR as compared with PR(fraction).
authors.affiliation: Department of Cardiology, Toronto Congenital Cardiac Centre for Adults, Peter Munk Cardiac Centre, University Health Network, Toronto General Hospital, North Wing, 5N-517, 585 University Avenue, Toronto, Ontario, Canada M5G 2C4. rachel.wald@uhn.on.ca
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Wald
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Redington
authors.forename: Andre
authors.initials: A
authors.lastname: Pereira
authors.forename: Yves L
authors.initials: YL
authors.lastname: Provost
authors.forename: Narinder S
authors.initials: NS
authors.lastname: Paul
authors.forename: Erwin N
authors.initials: EN
authors.lastname: Oechslin
authors.forename: Candice K
authors.initials: CK
authors.lastname: Silversides
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011183:Postoperative Complications / Q000175:diagnosis*; D011651:Pulmonary Artery / Q000503:physiopathology; D011665:Pulmonary Valve Insufficiency / Q000175:diagnosis* / Q000209:etiology*; D012189:Retrospective Studies; D013318:Stroke Volume; D013771:Tetralogy of Fallot / Q000601:surgery*; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D055815:Young Adult