Secundum atrial septal defect is a dynamic three-dimensional entity

Background The aim of this study was to evaluate the diagnostic relevance o f 3-dimensional (3D) echocardiography in the assessment of secundum atrial septum defect (ASD2). Methods and Results Twenty-three patients (age 2 to 58 years) with an ASD2 were studied by transthoracic (n = 9) or transesophageal (n = 14) echocardi ography for the acquisition of a 3D data set before undergoing surgical rep air. Qualitative (location, shape, and structure) and quantitative (largest and smallest anteroposterior and superoinferior diameters) characteristics were analyzed and compared with surgical findings. Intraobserver and inter observer variability were assessed. The gross anatomy of the ASD2, shown by the 3D images, was confirmed by the surgeon in 21 of 23 patients, but the presence of membranous or fenestrated remnants of the valvula foramina oval is in the defect was not optimally visualized in 7 patients. Three-dimensio nal echocardiography revealed changes in diameter and shape of the ASD2 dur ing the cardiac cycle. The measured largest and smallest anteroposterior di ameters and their intraobserver and interobserver agreement were 274 +/- 12 mm, r = 0.95 (P <.001), r = 0.92 (P <.001), and 194 +/- 9 mm, r = 0.96 (P <.001), r = 0.94 (P <.001), respectively. The measured largest and smallest superoinferior diameter and their intraobserver and interobserver agreemen t were 304 +/- 26 mm, r = 0.90 (P <.001), r = 0.97 (P <.001), and 204 +/- 1 0 mm, r = 0.83 (P <.001), r = 0.84 (P <.001), respectively. The correlation coefficient between 2D and 3D echocardiography for the largest anteroposte rior and superoinferior diameter was r = 0.69 (P <.001) and r = 0.68 (P =.0 5), respectively. The correlation coefficient between the measurements from 3D reconstructions and direct surgical measurements was r = 0.20 (P = not significant) and r = 0.57 (P <.05), whereas between 2D and surgery was r = 0.50 (P <.05) and r = 0.26 (P = not significant). Conclusions ASD2 has a complex morphology. Three-dimensional echocardiograp hy provides better qualitative and quantitative information on its dynamic geometry, location, and extension as compared with standard 2D echocardiogr aphy and might be useful for device selection during catheter-based closure of ASD2.