Flow Characteristics of the SAPIEN Aortic Valve: The Importance of Recognizing In-Stent Flow Acceleration for the Echocardiographic Assessment of Valve Function

Improving the Accuracy of Effective Orifice Area Assessment after Transcatheter Aortic Valve Replacement: Validation of Left Ventricular Outflow Tract Diameter and Pulsed-Wave Doppler Location and Impact of Three-Dimensional Measurements

“…The hemodynamic evaluation of these valves has become an integral part of assessing procedural success, long-term durability and complications, and recent guidelines suggest that preand postimplantation assessment should be performed with echocardiography. 17 Although measurements of both LVOT diameter and LVOT VTI proximal to the THV stent have been advocated, 11,12,18,19 validation of the accuracy of this method for calculating THV area is lacking. Calculation of EOA by echocardiography requires an accurate measurement of SV.…”

“…Although the assessment of surgically placed prosthetic valve function is well established, 10 the assessment of THV function has limited validation. 11,12 Unlike the surgical bioprosthetic valve, the THV has no sewing ring and the level of the leaflet coaptation is near the center of the stent. This results in a region within the stent below the coaptation of the cusps.…”

Flow Characteristics of the Medtronic CoreValve: Difficulties Estimating Aortic Valve Cross-Sectional Area Following Transcatheter Aortic Valve Implantation

“…All recordings were made at a sweep speed of 100 mm/s, with a superimposed eCg (lead II). A: The distance from the ventricular aspect of the device to the base of the neo-aortic leaflets in the SAPIEN valves is short (7.7mm, 8.7mm, and 11.6mm Site-Specific Measurement of Sub-Valvular SV Sub-valvular diameter: using a zoomed 2d parasternal long axis full-screen display, 'pre-stent' diameter was measured (in mid-systole, using inner-edge to inner-edge methodology, perpendicular to the tAVI device long axis) just underneath the apical margin of the valve stent [12][13][14] . After that, 'in-stent, pre-valve' diameter was measured (again using a zoomed parasternal mid-systolic frame, using inner-edge to inner-edge methodology perpendicular to the tAVI device long axis) just below the hinge points of the visible prosthetic leaflets 15 .…”

“…of the valve stent [12][13][14] . subsequently, 'in-stent, pre-valve' VtI was measured in mid-systole with the pulsed-wave doppler sample volume approximately 1cm below the neo-aortic valve 9 .…”

“…these differences in neo-aortic valve height are confirmed in representational 2-dimensional echo pictures shown in Figures 2A and 2B. the unique shape of different tAVI devices has specific influence on sub-valvular flow acceleration across the implanted valve. In the sApIeN device, flow acceleration occurs 'prestent' and 'in-stent, pre-valve' [11][12][13] . previous studies thus recommend using sub-valvular sV values 'pre-stent' to avoid 'in-stent' sub-valvular flow acceleration.…”