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 atrioventricu lar septal defect (AVSD) surgery. The relation of the valve leaflet morphol ogy and the MR mechanism remains a conundrum. Two-dimensional echocardiogra phy depicts leaflet edges, whereas volume-rendered 3-dimensional echocardio graphy provides direct visualization of the surface areas of the mitral val ve leaflets. This study examines the relation of mitral valve anatomy as de termined by 3-dimensional echocardiography with MR origins in patients afte r AVSD repair. Twenty-seven patients with AVSD surgery and Doppler color MR were prospectively enrolled (median age was 5 years and 16 patients had Do wn syndrome). Doppler color flow imaging of the MR jet and 3-dimensional ec hocardiography of the mitral valve were performed with a probe in the trans thoracic or transesophageal position. Enface 3-dimensional views of the mit ral valve from the left atrium were reconstructed. Analysis of the 3-dimens ional 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%, m ural 25 +/- 6%). Both intra and interobserver variability on the area measu rements were <5%. In 12 patients (group 1) the jet appeared to emanate medi ally from the region of coaptation of the superior and inferior components of the anterior leaflet. In 9 patients (group 2) the jet emanated more late rally from the region toward the mural leaflet The area ratios of the infer ior 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-dimensiona l echocardiography provides new insight into the anatomic determinants of M R following AVSD surgery. (C)1999 by Excerpta Medica, Inc.