title: Exercise capacity and biventricular function in adult patients with repaired tetralogy of Fallot.
abstract: BACKGROUND
  Adult patients with repaired tetralogy of Fallot (rTOF) often have diminished exercise capacity. The primary objective of this study was to examine whether abnormalities of biventricular function play a role in exercise limitation in patients with rTOF.
  
  
  METHODS
  This was a retrospective review of 99 adult patients with rTOF. Right ventricular (RV) and left ventricular (LV) function were assessed echocardiographically using the myocardial performance index (MPI). Maximal oxygen consumption (VO(2) Max) was measured during a level 1 cardiopulmonary exercise test.
  
  
  RESULTS
  The mean age of the cohort was 34 +/- 11 years (50% females). Although most of the patients reported good functional capacity, the peak Vo(2)max was decreased at 22 +/- 6 mL/kg per minute (66% +/- 13% predicted Vo(2)max for age and sex). The mean RV and LV MPI were 0.30 +/- 0.07 and 0.42 +/- 0.09, respectively. In the multivariate model, higher RV MPI (P = .04) and LV MPI (P = .005) values, representing impaired ventricular function, were associated with diminished Vo(2)max. There was a significant correlation between the RV and LV MPI (r = 0.54, P = .001).
  
  
  CONCLUSIONS
  Impairment of RV and LV function, as measured by MPI, is associated with diminished exercise capacity in patients with repaired tetralogy of Fallot. Furthermore, there is a linear relationship between the RV and LV function suggesting that ventricular interactions are contributing to the limited exercise capacity in this group of patients. Strategies aimed at preserving biventricular function or improving adverse ventricular interactions could help to improve functional capacity in these patients.
authors.affiliation: Toronto Congenital Cardiac Centre for Adults, University of Toronto, University Health Network, Toronto, Ontario, Canada.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Samman
authors.forename: Markus
authors.initials: M
authors.lastname: Schwerzmann
authors.forename: Olga H
authors.initials: OH
authors.lastname: Balint
authors.forename: David
authors.initials: D
authors.lastname: Tanous
authors.forename: Andrew
authors.initials: A
authors.lastname: Redington
authors.forename: John
authors.initials: J
authors.lastname: Granton
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Siu
authors.forename: Candice K
authors.initials: CK
authors.lastname: Silversides
mesh_terms: D000328:Adult; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000379:methods; D015331:Cohort Studies; D018619:Echocardiography, Doppler, Pulsed; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006334:Heart Function Tests; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010101:Oxygen Consumption / Q000502:physiology; D011336:Probability; D012189:Retrospective Studies; D013318:Stroke Volume; D013771:Tetralogy of Fallot / Q000175:diagnosis / Q000601:surgery*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology