title: [Quantitative assessment of jet velocities and pressure gradients in experimentally induced aortic membranous and tunnel-like stenoses].
abstract: To assess the quantitative relationship between jet velocities and pressure gradients in membranous and tunnel-like stenoses, Doppler echo-cardiography(DE) and cardiac catheterization(CC) were performed simultaneously in 6 open-chested anaesthetized dogs. A nonelastic strip was put around the canine ascending aorta through a metal tube and tightened to produce a stenotic lesion. The cross sectional area of the aortic lumen was gradually decreased while the length of the stenotic lesion gradually increased by using strips with different width. The jet velocities and pressure gradients were recorded simultaneously using the continuous-wave Doppler and dual catheter techniques. The comparison of the peak (delta Pp) and the mean (delta Pm) pressure gradients measured by DE and CC yielded high correlations (r = 0.98, SEE = 1.17Kpa, and r = 0.97, SEE = 0.89Kpa, respectively). However, in lesions where the ratio of the length over the radius(1/r) of the stenotic segment was more than 3, DE significantly underestimated delta Pp and delta Pm measured by CC(P less than 0.001). We conclude that DE can accurately predict pressure gradients across membranous and tunnel-like stenoses, but significant underestimation may occur in stenotic lesions with 1 more than 14mm and 1/r more than 3.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001011:Aorta / Q000503:physiopathology; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001794:Blood Pressure; D004285:Dogs; D015150:Echocardiography, Doppler