4.3 The role of 3D TEE compared to MDCT
Recent valvular heart disease guidelines and literature have recognized the importance of advanced cardiovascular imaging, especially 3D TEE and cardiac CT.7,8,19 MDCT provides a 3D dataset with good to excellent visualization of anatomic details of the MV and LVOT, enabling us to analyze the AM angle and predicted neo-LVOT area, which seems to contribute to the assessment of LVOT obstruction risk as well as patient selection, planning, and valve sizing for TMVI procedure.9,20 On the other hand, echocardiography including 3D TEE could be an alternative to MDCT in such patients as those with unstable clinical status, known allergy to iodinated contrast, kidney disease, tachycardia, and unable to hold their breath. Our results contribute to the risk stratification of the increase in LVOT gradient after procedure. More importantly, TMVI cannot be performed without real-time 2D and 3D TEE as it provides guidance for transseptal puncture and crossing, alignment of the delivery system using either a 3D en facesurgical view or a simultaneous multiplane (orthogonal) 2D view, and assessment for perivalvular leakage and LVOT obstruction after TMVI.7,8,21 Furthermore, analysis of newly created LVOT area by real-time 3D TEE just after deployment of the stent valve in the catheterization-lab not only confirms the success of TMVI but also may predict future LVOT obstruction.