title: Plasma brain natriuretic peptide levels, right ventricular volume overload and exercise capacity in adolescents after surgical repair of tetralogy of Fallot.
abstract: BACKGROUND
  Right ventricular (RV) volume overload secondary to pulmonary regurgitation contributes to long-term morbidities in patients after tetralogy of Fallot (TOF) repair. We tested the hypothesis that plasma brain natriuretic peptide (BNP) levels relate to RV volume overload, pulmonary regurgitation, and exercise capacity in adolescents after TOF repair.
  
  
  METHODS
  We assessed the RV function echocardiographically and plasma BNP levels in 32 postoperative TOF patients aged 14.7+/-3.1 years and 20 age-matched controls. Eighteen patients further underwent cardiovascular magnetic resonance imaging and 26 had exercise testing.
  
  
  RESULTS
  Compared with controls, patients had significantly higher BNP levels (p=0.027), greater indexed RV end-diastolic dimension (p<0.001), increased RV myocardial performance index (p=0.005), and reduced tricuspid annular systolic velocity (p=0.008). Multivariate analysis identified indexed RV end-diastolic dimension as the only significant determinant of plasma BNP levels (beta=0.69, p<0.001). Plasma BNP levels correlated positively with indexed RV end-diastolic volume (r=0.6, p=0.009) and pulmonary regurgitant fraction (r=0.54, p=0.026), and negatively with exercise duration (r=-0.45, p=0.021), peak oxygen consumption (r=-0.43, p=0.03), and minute ventilation at maximal exercise (r=-0.52, p=0.006). Multivariate analysis demonstrated BNP levels (beta=-0.43, p=0.034) and body mass index (beta=-0.40, p=0.036) to be independent predictors of peak oxygen consumption. No relations were found between BNP levels and RV myocardial performance index, tricuspid annular velocities and RV ejection fraction.
  
  
  CONCLUSIONS
  In adolescent patients after TOF repair, plasma BNP levels relate to RV volume overload, pulmonary regurgitation and exercise capacity.
authors.affiliation: Division of Paediatric Cardiology, Grantham Hospital, The University of Hong Kong, Hong Kong, China.
authors.forename: Eddie W Y
authors.initials: EW
authors.lastname: Cheung
authors.forename: Wendy W M
authors.initials: WW
authors.lastname: Lam
authors.forename: Clement S W
authors.initials: CS
authors.lastname: Chiu
authors.forename: Adolphus K T
authors.initials: AK
authors.lastname: Chau
authors.forename: Stephen C W
authors.initials: SC
authors.lastname: Cheung
authors.forename: Yiu-fai
authors.initials: YF
authors.lastname: Cheung
mesh_terms: D000293:Adolescent; D002648:Child; D015331:Cohort Studies; D005080:Exercise Test / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D013771:Tetralogy of Fallot / Q000097:blood* / Q000503:physiopathology / Q000601:surgery*; D018497:Ventricular Dysfunction, Right / Q000097:blood* / Q000503:physiopathology / Q000601:surgery; D016278:Ventricular Function, Right / Q000502:physiology
chemical_list: D020097:Natriuretic Peptide, Brain