Three-dimensional echocardiographic analysis of valve anatomy as a determinant of mitral regurgitation after surgery for atrioventricular septal defects. 
Mitral regurgitation (MR) is a significant complication after atrioventricular septal defect (AVSD) surgery.  The relation of the valve leaflet morphology and the MR mechanism remains a conundrum.  Two-dimensional echocardiography depicts leaflet edges, whereas volume-rendered 3-dimensional echocardiography provides direct visualization of the surface areas of the mitral valve leaflets.  This study examines the relation of mitral valve anatomy as determined by 3-dimensional echocardiography with MR origins in patients after AVSD repair.  Twenty-seven patients with AVSD surgery and Doppler color MR were prospectively enrolled (median age was 5 years and 16 patients had Down syndrome).  Doppler color flow imaging of the MR jet and 3-dimensional echocardiography of the mitral valve were performed with a probe in the transthoracic or transesophageal position.  Enface 3-dimensional views of the mitral valve from the left atrium were reconstructed.  Analysis of the 3-dimensional data was possible in 21 of the 27 patients.  Mean area ratios of the 3 mitral leaflets were calculated (superior 40 +/- 7%, inferior 35 +/- 5%, mural 25 +/- 6%).  Both intra and interobserver variability on the area measurements were <5%.  In 12 patients (group 1) the jet appeared to emanate medially from the region of coaptation of the superior and inferior components of the anterior leaflet.  In 9 patients (group 2) the jet emanated more laterally from the region toward the mural leaflet.  The area ratios of the inferior leaflet were 32 +/- 4% in group 1 and 38 +/- 6% in group 2 (p = 0.02).  The area ratios of the mural leaflet were 28 +/- 5% in group 1 and 21 +/- 5% in group 2 (p = 0.007).  The superior leaflet area ratio was not different in groups 1 and 2, 40 +/- 9% and 41 +/- 6%, respectively.  Three-dimensional echocardiography provides new insight into the anatomic determinants of MR following AVSD surgery.