Imaging in mitral stenosis: assessment before, during and after percutaneous balloon mitral valvuloplasty

Level of agreement in three-dimensional planimetric measurement of mitral valve area between transthoracic and transesophageal echocardiography

BACKGROUND

Echocardiographic measurement of mitral valve area (MVA) is critical prior to percutaneous transmitral commissurotomy (PTMC). This study aimed to compare the agreement between transthoracic (TTE) and transesophageal echocardiography (TEE) in three-dimensional (3D) planimetric measurement of the MVA among patients with severe mitral stenosis.

METHODS

MVA was measured with planimetry in 105 patients before undergoing PTMC. 3D reconstruction was applied to both TTE and TEE examinations. The MVA values from four different methods of 3D reconstruction were compared to the average values of 3D methods in TEE as the gold standard measurement method for the MVA in this study. The agreement levels between the two examinations were evaluated and analyzed for various reconstruction methods.

RESULTS

The mean age was 49 ± 12 years for 28 men and 77 women who were enrolled. The image quality was graded as "excellent" in 57% of 3D images obtained by TTE, while it was graded as "excellent" in 81% of 3D images obtained by TEE. The ventricular zooming method in TTE with a bias of -0.006 ± 0.065 cm² (P < 0.0001) had the highest agreement with the 3D-MVA in TEE. While 2D-TTE and 3D-TEE measurements of the MVA (R = 0.91; P < 0.0001) were significantly correlated, 2D-TTE overestimated the MVA by 0.19 cm² .

CONCLUSION

Although the quality of 3D images was significantly better in TEE than those in TTE, a good agreement existed between the measured 3D-TTE and 3D-TEE studies. We also demonstrated that 2D-TTE overestimated the MVA compare to 3D-TEE.

Echocardiography-guided interventions

A major advantage of echocardiography over other advanced imaging modalities (magnetic resonance imaging, computed tomographic angiography) is that echocardiography is mobile and real time. Echocardiograms can be recorded at the bedside, in the cardiac catheterization laboratory, in the cardiovascular intensive care unit, in the emergency room-indeed, any place that can accommodate a wheeled cart. This tremendous advantage allows for the performance of imaging immediately before, during, and after various procedures involving interventions. The purpose of this report is to review the use of echocardiography to guide interventions. We provide information on the selection of patients for interventions, monitoring during the performance of interventions, and assessing the effects of interventions after their completion. In this document, we address the use of echocardiography in commonly performed procedures: transatrial septal catheterization, pericardiocentesis, myocardial biopsy, percutaneous transvenous balloon valvuloplasty, catheter closure of atrial septal defects (ASDs) and patent foramen ovale (PFO), alcohol septal ablation for hypertrophic cardiomyopathy, and cardiac electrophysiology. A concluding section addresses interventions that are presently investigational but are likely to enter the realm of practice in the very near future: complex mitral valve repairs, left atrial appendage (LAA) occlusion devices, 3-dimensional (3D) echocardiographic guidance, and percutaneous aortic valve replacement. The use of echocardiography to select and guide cardiac resynchronization therapy has recently been addressed in a separate document published by the American Society of Echocardiography and is not further discussed in this document. The use of imaging techniques to guide even well-established procedures enhances the efficiency and safety of these procedures.