title: Exercise function of children with congenital aortic stenosis following aortic valvuloplasty during early infancy.
abstract: OBJECTIVE
  The objectives of this study were to characterize the exercise function of patients treated with balloon aortic valvuloplasty at <or=6 months of age, and identify factors associated with exercise dysfunction.
  
  
  BACKGROUND
  Balloon aortic valvuloplasty is the primary therapy for neonatal aortic stenosis (AS). Residual and/or acquired abnormalities of left heart structure and function may adversely affect exercise capacity. Methods. We prospectively recruited patients >6 years old with a history of neonatal AS to undergo exercise testing.
  
  
  RESULTS
  We enrolled 30 patients (median age 13.1 years) who underwent balloon aortic valvuloplasty at a median age of 12 days. At time of exercise testing, the median maximum Doppler AS gradient was 34 mm Hg (0-70 mm Hg); 11 patients had moderate or severe aortic regurgitation. All patients were asymptomatic. Overall, peak oxygen consumption (VO(2)) was below normal (87 +/- 18% predicted; P < .001), and was severely depressed (<or=70% predicted) in 7 patients (23%). Although peak O(2) pulse was well preserved overall (97 +/- 22% predicted; P= .36), 11 patients had an O(2) pulse <85% predicted, including all patients with VO(2)<or= 70% predicted. Peak heart rate was below normal overall (91 +/- 7% predicted, P < .001), but severe chronotropic dysfunction (<or=70% predicted) was rare (n = 1). Age at testing correlated inversely with peak VO(2) (R(2)= 0.30; P= .002). No other demographic, historical, or echocardiographic variables were associated with peak VO(2).
  
  
  CONCLUSIONS
  Although exercise function is preserved in most patients with a history of AS treated in early infancy, a subset have markedly reduced peak VO(2), usually because of inability to increase stroke volume.
authors: Department of Cardiology, Children's Hospital, Boston, Mass 02115, USA. akipps@post.harvard.edu
authors: Alaina K
authors: AK
authors: Kipps
authors: Doff B
authors: DB
authors: McElhinney
authors: Janet
authors: J
authors: Kane
authors: Jonathan
authors: J
authors: Rhodes
mesh_terms: D000293:Adolescent; D001021:Aortic Valve / Q000502:physiology / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000151:congenital / Q000503:physiopathology / Q000601:surgery; D002404:Catheterization; D002648:Child; D015444:Exercise; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013318:Stroke Volume / Q000502:physiology; D055815:Young Adult