Abstract 18731: Direct Assessment of St. Jude Mechanical Mitral Valve Orifice Area by 3 Dimensional Transesophageal Echocardiography
Background: We aimed to test the feasibility of 3D transesophageal echo (3DTEE) to directly measure mechanical mitral valve (MV) orifice area. 3D anatomic diastolic area (ADA) and 3D color Doppler diastolic area were compared to manufacturer-defined geometric orifice area (GOA), and spectral Doppler-derived effective orifice area (EOA).
Methods: Patients with normal St. Jude mechanical MV function by TEE were included. Images were optimized for 3D live zoom, and 3D color Doppler (7 beat stitch) acquisition. Doppler-derived EOA was obtained by transthoracic study within 24 hours. Each 3D dataset was manipulated to define 2 orthogonal long-axis views and a single short-axis view of the prosthetic valve. For each imaging modality, a planar diastolic valve area was directly measured from the short-axis view by manual tracing of the inner valve circumference (Figure). Mean area from 3 diastolic frames was recorded.
Results: 25 patients with normal bileaflet mechanical MV were studied. Age: 61 yrs ± 16; 15 female. Valve size 21- 33 mm; defined from the operative record. 3D image quality was diagnostic for all patients. Mean 3D live ADA was smaller but correlated well with GOA (3.13 cm2 ± 0.66 vs. 3.89 cm2 ± 0.81; R=0.81, p<0.001 respectively). 3D color Doppler area was even smaller with modest correlation to GOA (2.51 cm2 ± 0.58; R=0.65, p<0.001). Doppler-derived EOA was smallest (2.10 cm2 ± 0.56) and did not correlate to GOA or 3D valve areas. Measured 3D valve areas were highly reproducible; intraclass correlation coefficient: 0.91, p<0.001.
Conclusion: Direct measurement of mechanical mitral valve orifice area by 3DTEE is novel, feasible, reproducible, and correlates well with manufacturer-reported area. Valve area by 3D color Doppler gives intermediate values, between Doppler-derived EOA and geometric area. Visualization and quantitation of the prosthetic valve orifice area by 3DTEE may therefore be an important adjunct in evaluating prosthetic valve function.
- © 2010 by American Heart Association, Inc.