Impact of Net Atrioventricular Compliance on Mitral Valve Area Assessment-A Perspective Considering Three-Dimensional Mitral Valve Area by Transesophageal Echocardiography

Background: Net atrioventricular compliance (Cn) can affect the accuracy of mitral valve area (MVA) assessment. We assessed how different methods of MVA assessment are affected by Cn, and if patients with abnormal Cn may be identified by clinical and/or echocardiographic parameters. Methods: We studied 244 patients with rheumatic MS. The concordance between mitral valve area (MVA) by 2D planimetry, pressure half-time (PHT), continuity equation (CE), Yeo's index, and 3-dimensional mitral valve area assessed by transesophageal echocardiography (TEE 3DMVA) in patients with normal and abnormal Cn (Cn <= 4 mL/mmHg) were evaluated in the 110 patients with both transesophageal echocardiogram (TEE) and transthoracic echocardiogram (TTE). Variables that were associated with abnormal Cn were validated in the remaining 134 patients with only TTE. Results: Except for MVA by CE, concordance with TEE 3DMVA was poorer for all other methods of MVA assessment in patients with abnormal Cn. But, the difference in concordance was only statistically significant for MVA by PHT. Patients with MVA <= 1.5 cm2 by 2D planimetry and PHT <= 130 ms were likely to have an abnormal Cn. (specificity 98.5%). This finding was validated in the remaining 134 patients (specificity 93%). Conclusions: MVA assessment by PHT is significantly affected by Cn. Abnormal Cn should be suspected when 2D planimetry MVA is <= 1.5 cm2 together with an inappropriately short PHT that is <= 130 ms. In this scenario, MVA by PHT is inaccurate.