title: Abnormal ventilatory response to exercise in young adults operated for ventricular septal defect in early childhood: A long-term follow-up.
abstract: BACKGROUND
  Ventricular septal defects (VSDs) are normally closed in early childhood, and postsurgical physical capacity is generally considered normal. Despite an increasing understanding of late cardiac morbidity among these patients, long-term pulmonary function remains to be investigated. Therefore, the aim of this prospective follow-up study was to describe ventilatory function during exercise in VSD-repaired adults operated in early life.
  
  
  METHODS
  We tested cardiopulmonary exercise capacity in 27 patients and 30 healthy control subjects on an ergometer cycle. Each test was preceded by a standard spirometry, and the exercise test was performed as a maximal incremental test. Pulmonary ventilation and gas exchange were simultaneously measured breath-by-breath with minute ventilation at peak exercise as our main endpoint.
  
  
  RESULTS
  In the VSD-group the median surgical age was 1.9 (95% CI 1.1-2.8 years) and the mean age at time of examination was 21.1 ± 3.1 years in the VSD-group vs. 21.2 ± 2.5 years in the control group. Mean minute ventilation at peak exercise was significantly lower in the VSD-group compared with the controls: 1.4 ± 0.4 L/kg/min vs. 1.8 ± 0.4 L/kg/min, p<0.01. Likewise, mean oxygen uptake was reduced: 38.0 ± 8.2 ml/kg/min in the VSD-cohort vs. 47.9 ± 6.5 ml/kg/min among controls, p<0.01. In terms of breath rate and ventilatory equivalents (O2 and CO2) there were no differences between the groups.
  
  
  CONCLUSIONS
  Patients with a surgically closed VSD have a markedly abnormal ventilatory response to exercise with significantly reduced minute ventilation despite a similar breath rate. With a follow-up of almost two decades our finding most certainly reflects an unknown but persisting abnormality.
authors.affiliation: Dept. of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark; Dept. of Clinical Medicine and Centre of Research in Rehabilitation (CORIR), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark. Electronic address: johan.heiberg@clin.au.dk.
authors.forename: Johan
authors.initials: J
authors.lastname: Heiberg
authors.affiliation: Dept. of Physiotherapy and Occupational Therapy, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark; Dept. of Clinical Medicine and Centre of Research in Rehabilitation (CORIR), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
authors.forename: Annemette K
authors.initials: AK
authors.lastname: Petersen
authors.affiliation: Dept. of Physiotherapy and Occupational Therapy, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark; Dept. of Clinical Medicine and Centre of Research in Rehabilitation (CORIR), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
authors.forename: Sussie
authors.initials: S
authors.lastname: Laustsen
authors.affiliation: Dept. of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark; Dept. of Clinical Medicine and Centre of Research in Rehabilitation (CORIR), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200 Aarhus N, Denmark.
authors.forename: Vibeke E
authors.initials: VE
authors.lastname: Hjortdal
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002675:Child, Preschool; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006345:Heart Septal Defects, Ventricular / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012123:Pulmonary Ventilation / Q000502:physiology; D012129:Respiratory Function Tests; D055815:Young Adult
keywords: Cardiopulmonary exercise testing; Congenital heart disease; Long-term follow-up; Ventilatory function; Ventricular septal defect