VOLUME-RENDERED, 3-DIMENSIONAL ECHOCARDIOGRAPHIC DETERMINATION OF THESIZE, SHAPE, AND POSITION OF ATRIAL SEPTAL-DEFECTS - VALIDATION IN ANIN-VITRO MODEL

Accurate evaluation of atrial septal defect (ASD) size and shape is ve ry important for the selection of patients for transcatheter occlusion . The ability of volume-rendered, three-dimensional echocardiography ( 3DE) in displaying ASDs in a dynamic mode has been demonstrated; howev er, its accuracy in sizing ASDs is unknown. To assess this, we perform ed 3DE of 10 explanted pig hearts in which ASDs of various locations, sizes, and shapes had been experimentally created. From en face 3DE vi ews of the atrial septum containing the defects, major and minor diame ters of the defect were measured by a blinded observer, and these data were compared to direct anatomic measurements. The correlations betwe en 3DE and anatomy for the major and minor ASD diameters were y = 0.83 x + 3.4 (r = 0.97, p < 0.0001) and y = 0.92x + 1.3 (r = 0.92, p < 0.00 01) respectively. The correlation between the measures for major and m inor axis ratio was y = 1.06x - 0.052, r = 0.91, p < 0.0002. Good agre ement between both methods of measurements was demonstrated for all me asurements. In addition, 3DE portrayed the location and shape of the d efects accurately. Thus 3DE provides excellent visualization of ASD an d is able to accurately define the size of the defects. These qualitat ive and quantitative capabilities enhance the clinical potential of th is technique in the appraisal of ASDs for decisions regarding applicat ion of closure devices.