title: Exercise capacity and stroke volume are preserved late after tetralogy repair, despite severe right ventricular dilatation.
abstract: OBJECTIVE
  To assess if exercise capacity and resting stroke volume are different in tetralogy of Fallot (TOF) repair survivors with indexed RV (right ventricle) end-diastolic volume (RVEDVi) more versus less than 150 ml/m(2), a currently suggested threshold for pulmonary valve replacement (PVR).
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Single-centre adult congenital heart disease unit.
  
  
  METHODS
  55 consecutively eligible patients with repaired TOF (age at repair 2.3±1.9 years; age at evaluation 26.2±8.8 years; NYHA Class I or II).
  
  
  METHODS
  Cardiovascular MRI (1.5T) and cardiopulmonary exercise test.
  
  
  METHODS
  Biventricular volumes and function; exercise capacity.
  
  
  RESULTS
  20 patients had RVEDVi below, and 35 had RVEDVi above 150 ml/m(2), at time of referral. In the >150 ml/m(2) group, fractional pulmonary regurgitation was higher (41±8 vs 31±8%, p<0.001). Although RV ejection fraction (EF) was lower (47±7 vs 54±6%, p=0.007), indexed RV stroke volume was higher (87±14 vs 64±10 ml/m(2), p<0.001) in the >150 ml/m(2) group. There were no significant differences in LVEF, indexed LV stroke volume or exercise capacity (% predicted peak work: 90±17 vs 89±11% and; % predicted VO(2) peak: 84±17 vs 87±12%).
  
  
  CONCLUSIONS
  Exercise capacity and stroke volume are maintained with RVEDVi above compared with below a commonly used cut-off for PVR surgery. Optimal timing for PVR, thus, remains unclear.
authors.affiliation: The University of Sydney, Sydney, Australia.
authors.forename: Shamus
authors.initials: S
authors.lastname: O'Meagher
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Munoz
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Alison
authors.forename: Iven H
authors.initials: IH
authors.lastname: Young
authors.forename: David J
authors.initials: DJ
authors.lastname: Tanous
authors.forename: David S
authors.initials: DS
authors.lastname: Celermajer
authors.forename: Rajesh
authors.initials: R
authors.lastname: Puranik
mesh_terms: D000328:Adult; D006348:Cardiac Surgical Procedures / Q000379:methods*; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D011183:Postoperative Complications; D011379:Prognosis; D011665:Pulmonary Valve Insufficiency / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D012189:Retrospective Studies; D013318:Stroke Volume; D013771:Tetralogy of Fallot / Q000503:physiopathology / Q000601:surgery*; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D055815:Young Adult