|Procedural Step||Remarks Regarding Imaging|
|Prior to PMBV||Echocardiographic assessment for excluding left atrial/left atrial appendage thrombi and to reassess contraindications for PMBV|
|Transseptal puncture||The tip of the transseptal puncture needle can be identified by a tentlike indentation of the interatrial septum on TEE. Useful imaging views:|
|Balloon positioning||2D and 3D TEE are useful to guide delivery of catheters and wires across the MV, to position the balloon within the MV orifice, and to confirm that the balloon is optimally positioned between the MV leaflets.|
|Balloon dilation||Dilation of the MV orifice due to splitting of the commissures is confirmed by echocardiography and fluoroscopy:|
|Evaluation post-PMBV||The evaluation after balloon dilation by TEE includes:|
2D = 2-dimensional; MR = mitral regurgitation; TEE = transesophageal echocardiography; other abbreviations as in Tables 1 and 2.
↵∗ The pressure half-time method post-PMBV is unreliable for calculation of MV area because of multiple factors, including atrial compliance, a newly created atrial septal defect, and changes in hemodynamics, which can influence the reliability of this measurement.