title: Systemic ventricular outflow obstruction progresses after the Fontan operation.
abstract: To evaluate the course of systemic ventricular outflow obstruction after the Fontan operation, the records of 57 hospital survivors of that procedure were reviewed. Ventricular outflow obstruction was identified in 7 patients (group 1) and was absent in 50 patients (group 2). Overall, the ventricular outflow gradient in group 1 was 6.3 +/- 2.9 mm Hg (mean +/- standard error) before the Fontan operation and 7.6 +/- 3.9 mm Hg at hospital discharge. Ventricular outflow obstruction subsequently progressed to 80.1 +/- 17.3 mm Hg (range, 33 to 165 mm Hg; p < 0.02) a mean of 28 months postoperatively. One patient died of severe progressive ventricular outflow obstruction. Group 1 did not differ from group 2 in age, ventricular morphology, presence of a subaortic outflow chamber, prior shunt, or length of follow-up. Compared with group 2, however, patients in group 1 more commonly had an aorta arising from a hypoplastic ventricle (p < 0.001) and had undergone prior pulmonary artery banding (p = 0.005). We conclude that systemic ventricular outflow obstruction occurs commonly after a Fontan procedure (incidence, 12%; 70% confidence interval, 9% to 18%) and is a progressive lesion.
authors.affiliation: Division of Pediatric Cardiology, C. S. Mott Children's Hospital, University of Michigan, Ann Arbor.
authors.forename: K M
authors.initials: KM
authors.lastname: Finta
authors.forename: R H
authors.initials: RH
authors.lastname: Beekman
authors.forename: F M
authors.initials: FM
authors.lastname: Lupinetti
authors.forename: E L
authors.initials: EL
authors.lastname: Bove
mesh_terms: D002675:Child, Preschool; D018450:Disease Progression; D018729:Fontan Procedure / Q000009:adverse effects*; D006331:Heart Diseases / Q000601:surgery; D006801:Humans; D012189:Retrospective Studies; D014694:Ventricular Outflow Obstruction / Q000209:etiology*