title: Effect of right ventricular outflow tract obstruction on right ventricular volumes and exercise capacity in patients with repaired tetralogy of fallot.
abstract: Patients with tetralogy of Fallot and combined right ventricular outflow tract obstruction (RVOTO) and pulmonary regurgitation (PR) have a less dilated right ventricular (RV) and better RV function compared with patients without RVOTO. It is not known whether RVOTO is associated with improved exercise capacity. We compared cardiac magnetic resonance imaging, echocardiography, and exercise tests in 12 patients with RVOTO (Doppler peak RVOT gradient ≥30 mm Hg) and 30 patients without RVOTO. RV end-systolic and end-diastolic volumes were smaller in patients with RVOTO compared with patients without RVOTO (50 ± 16 vs 64 ± 18 ml/m(2) and 117 ± 24 vs 135 ± 28 ml/m(2), respectively) and patients with RVOTO had a higher RV mass (52 ± 14 vs 42 ± 11 ml/m(2)), p <0.05. RV ejection fraction was marginally significantly different between both groups (58 ± 8% vs 53 ± 7%), p = 0.051. Degree of PR, left ventricular volumes, and function did not differ significantly between both groups. Peak oxygen uptake in patients with RVOTO was significantly lower (25 ± 3 vs 32 ± 8 ml/kg/min) than in patients without RVOTO, as was the percentage of predicted peak oxygen uptake (63 ± 7% vs 79 ± 14%), p <0.001. Multivariate analysis showed that the peak RVOT gradient was the only independent predictor of exercise capacity. In conclusion, exercise capacity is lower in patients with RVOTO compared with those without RVOTO despite a less dilated RV and comparable degree of PR. Therefore, exercise capacity may be of importance and should additionally be taken in consideration to RV volumes and function in patients with tetralogy of Fallot and PR.
authors.affiliation: Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Interuniversity Cardiology Institute of the Netherlands, Utrecht, The Netherlands.
authors.forename: Hendrik G
authors.initials: HG
authors.lastname: Freling
authors.affiliation: Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Tineke P
authors.initials: TP
authors.lastname: Willems
authors.affiliation: Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Joost P
authors.initials: JP
authors.lastname: van Melle
authors.affiliation: Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Interuniversity Cardiology Institute of the Netherlands, Utrecht, The Netherlands; Department of Cardiothoracic Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Ymkje J
authors.initials: YJ
authors.lastname: van Slooten
authors.affiliation: Department of Pediatric Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Beatrijs
authors.initials: B
authors.lastname: Bartelds
authors.affiliation: Department of Pediatric Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Rolf M F
authors.initials: RM
authors.lastname: Berger
authors.affiliation: Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: van Veldhuisen
authors.affiliation: Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. Electronic address: p.g.pieper@umcg.nl.
authors.forename: Petronella G
authors.initials: PG
authors.lastname: Pieper
mesh_terms: D000328:Adult; D002675:Child, Preschool; D004452:Echocardiography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013771:Tetralogy of Fallot / Q000503:physiopathology* / Q000601:surgery*; D016278:Ventricular Function, Right / Q000502:physiology*; D014694:Ventricular Outflow Obstruction / Q000503:physiopathology*