title: Left ventricular mid-cavitary obstruction after balloon dilation in isolated aortic valve stenosis in children.
abstract: A hyperdynamic left ventricle can lead to post-dilation mid-cavitary obstruction in the absence of any preballoon mid-cavitary obstruction in children with aortic valve stenosis. The purpose of this study was to define the incidence and course of post-dilation mid-cavitary obstruction. We reviewed the catheterization and echocardiographic data of 35 patients, ages 3 days to 18 years (mean = 7.9 years), with isolated aortic valve stenosis who underwent balloon dilation with a fall in aortic valve gradient to less than 20 mm Hg. Post-dilation mid-cavitary obstruction was suspected from post-dilation left ventricular angiogram and was quantitated by echocardiographic and Doppler examinations performed immediately after dilation and in a 1-3 month follow-up period. Continuous wave Doppler directed by color flow Doppler was used for evaluation and differentiation of post-dilation mid-cavitary obstruction and residual aortic valve stenosis. Three children (3/35 [9%]) all under 2 years of age developed post-dilation mid-cavitary obstruction immediately after dilation. The obstruction within the cavity resolved spontaneously in all three patients.
  
  
  CONCLUSIONS
  1) Post-dilation left ventricular mid-cavitary obstruction can occur in children under 2 years of age after balloon dilation of severe aortic valve stenosis, and 2) total regression of post-dilation mid-cavitary obstruction occurs spontaneously in all patients.
authors.affiliation: Lillie Frank Abercrombie Section of Pediatric Cardiology, Baylor College of Medicine, Texas Children's Hospital, Houston 77030.
authors.forename: A
authors.initials: A
authors.lastname: Ludomirsky
authors.forename: M P
authors.initials: MP
authors.lastname: O'Laughlin
authors.forename: M R
authors.initials: MR
authors.lastname: Nihill
authors.forename: C E
authors.initials: CE
authors.lastname: Mullins
mesh_terms: D001024:Aortic Valve Stenosis / Q000628:therapy*; D002404:Catheterization; D002648:Child; D004452:Echocardiography; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology; D014694:Ventricular Outflow Obstruction / Q000000981:diagnostic imaging / Q000453:epidemiology*