DK2985_C000 1..28 - AlSharqia Echo Club

Native Aortic Valve 339(A)(B)MVAoVLVAoFigure 15.14 (A, B) Basal transgastric view of the aortic valve (AoV). Note the alignment of the Doppler signal with aortic bloodflow. In this view, the mitral valve (MV) is imaged in a short-axis view (Ao, aorta; LV, left ventricle).Pitfalls of Pressure GradientPRESSURE RECOVERY. Pressure recovery is theincrease in pressure which occurs downstream from a stenosisdue to reconversion of kinetic energy into potentialenergy. Pressure recovery is an important phenomenonwhich may result in a measured Doppler mean systolicgradient that is 3–54 mmHg higher than the measuredcatheter gradient. Indeed, the Doppler measurementreflects the highest pressure gradient across the stenosis,or the difference between the highest proximal pressureand the lowest distal pressure, which occurs immediatelydownstream from the AoV at the vena contracta. TheDoppler measured gradient should correspond to the invasivelymeasured gradient if the catheter is positioned at thelevel of the vena contracta. However, the catheter is frequentlypositioned in the ascending Ao rather than at thelevel of the vena contracta. This explains in part, the discrepancyobserved between Doppler- and catheterderivedpressure gradients across the AoV. The measuredpressure gradient will progressively decrease over several(A)(B)AoVLATVRAPVRV(C)(D)LALVAoRVFigure 15.15 (A, B) Mid-esophageal short-axis view of the aortic valve (AoV) in a patient with severe calcific non-rheumatic aorticstenosis. Note the absence of commissural fusion in this patient. (C, D) Mid-esophageal long-axis view of the AoV in a patient with rheumaticheart disease. Note systolic doming (arrow) and commissural fusion characteristic of rheumatic heart disease (Ao, aorta; LA, leftatrium; LV, left ventricle; PV, pulmonic valve; RA, right atrium; RV, right ventricle; TV, tricuspid valve).