4.4 The role of 3D TEE compared to 2D TEE
In a clinical setting, we used to suspect LVOT obstruction when we saw the encroachment of the stent valve toward LVOT space by 2D LV long-axis views. Also, we’ve frequently experienced that a stent valve may severely encroach into the LVOT without significant subsequent elevation of LVOT velocity. This apparent discrepancy may be explained by this study; the dimension between the stent struts and ventricular septum from 2D LV long-axis view was the minimum at the valve stent distal edge, while 3D derived LVOT cross sectional area was typically the maximum at the valve stent distal edge (Figure 4). Our study suggests the need of the 3D TEE if LVOT obstruction is suspected during or after the procedure by 2D LV long-axis view.