title: Significance of the Doppler-derived gradient across a residual aortic coarctation.
abstract: Few data exist which address the significance of the Doppler gradient across a residual narrowing in older children who have had a coarctation repaired. Therefore, we evaluated 11 patients with repaired aortic coarctation with and without residual obstruction by Doppler echocardiography. The Doppler-derived transcoarctation pressure gradient correlated poorly with catheter-measured peak-to-peak and catheter maximal instantaneous gradients when only the maximal velocity across the repair was utilized in the simplified Bernoulli equation, [r = 0.73, standard of error of the estimate (SEE) = 5.0 mmHg and r = 0.56, SEE = 7.6 mmHg, respectively]. However, when the precoarctation velocity was included in the simplified Bernoulli equation, the correlation between Doppler-derived and catheter-measured gradients became excellent. The maximal Doppler gradient correlated well with catheter peak-to-peak gradient (r = 0.95, SEE = 2.2 mmHg) and catheter maximal instantaneous gradient (r = 0.94, SEE = 3.2 mmHg). However, the maximal Doppler gradient slightly overestimated the catheter peak-to-peak gradient and underestimated the catheter maximal instantaneous gradient. The Doppler mean gradient showed excellent correlation with the catheter mean gradient (r = 0.97, SEE = 0.85 mmHg). Precoarctation velocities were generally twofold greater than published normals due to a spatial acceleration phenomenon. All subjects had residual hypoplasia of the transverse aorta such that its transverse diameter was 29% less than, and its cross-sectional area was 50% less than, the ascending and descending aorta.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Pediatrics, University of Tennessee, School of Medicine, Memphis.
authors.forename: A W
authors.initials: AW
authors.lastname: Aldousany
authors.forename: T G
authors.initials: TG
authors.lastname: DiSessa
authors.forename: B S
authors.initials: BS
authors.lastname: Alpert
authors.forename: S E
authors.initials: SE
authors.lastname: Birnbaum
authors.forename: E S
authors.initials: ES
authors.lastname: Willey
mesh_terms: D000293:Adolescent; D000328:Adult; D001017:Aortic Coarctation / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D001783:Blood Flow Velocity; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology