DK2985_C000 1..28 - AlSharqia Echo Club

Native Aortic Valve 341(A)(B)LAAoVLVAoSUPRA-VALVULARSTENOSISRV(C)(D)LAAoVLVAoSUPRA-VALVULARSTENOSISRV(E) Max Vel: 452cm/sMn Vel: 341cm/sVelocity: 123cmMax PG: 81.7mmHgMn PG: 51.2mmHgFigure 15.17 Mid-esophageal long-axis view in a 25-year-old woman operated on for supravalvular aortic stenosis. (A–D) Midesophageallong-axis view showing the normal opening of the aortic cusps but a stenosing membrane is present 9 mm above the levelof the aortic valve (AoV). (E) A maximal (Max) and mean (Mn) pressure gradient (PG) of 81.7 and 51.2 mmHg, respectively, is measuredacross the stenosing membrane (Ao, aorta; LA, left atrium; LV, left ventricle; RV, right ventricle; Vel, velocity).gradients and assumes V 1 (velocity in the LVOT) to benegligible in the calculation. However, when subaorticLVOT velocities are increased, this assumption is nolonger valid. The ASE task force on Doppler quantificationsrecommends that a V 1 value .1.5 m/s must beincluded in the calculations for the Bernoulli equation(7). This will usually occur in patients with subaorticobstruction or narrowing as seen in HOCM or severebasal septal hypertrophy. Other instances where V 1 maybe increased, and should be accounted for, include thepediatric patient and hyperdynamic states (e.g. sepsis,stress, severe anemia, hyperthyroidism, etc.). Finally,significant aortic regurgitation (AR) may also result in alarge stroke volume (SV) and increased V 1 . In those situations,software from most echocardiographic systemscan be reprogrammed to include V 1 in the calculation ofpressure gradients.PRESSURE GRADIENT AND SERIAL STENOSIS. Inpatients with dynamic LVOT obstruction and SAM, it isdifficult to determine the proportion of the pressure gradientthat is attributable to the obstruction at the valvular vsthe subvalvular level (e.g. HOCM). Planimetry of theAVA by 2D imaging may help identify the degree of stenosisat the valve level in this situation. Measurement ofV 1 proximal to the AoV and distal to the subvalvular