Abstract 753: Assessment of Atrial Septal Defect Anatomy by Real-Time Three-dimensional Transesophageal Echocardiography and Residual Shunting After Transcatheter Atrial Septal Defect Closure
Background: Successful transcatheter closure of atrial septal defects (ASD) requires accurate assessment of defect size and morphology. The interatrial septum is a concave three-dimensional (3D) structure and ASDs are often irregularly shaped. As such, accurate assessment of ASD anatomy may be difficult by two-dimensional (2D) echocardiography. We hypothesize that real-time 3D transesophageal echocardiography (TEE) may provide more accurate morphologic assessment of ASDs than multiplane 2D TEE.
Methods: Multiplane 2D and real-time 3D TEE imaging was acquired in 25 patients undergoing transcatheter ASD closure using a matrix array 3D TEE probe (Philips Ultrasound, MA). Closure device size was based on 2D TEE. 3D images were assessed offline. ASD shape assessed by 3D TEE was classified as circular, oval, or complex. The maximum ASD dimension measured by 3D TEE was compared to the largest diameter measured by 2D imaging. The defect area by 3D planimetry was compared to the area calculated by the ellipse formula by 2D imaging.
Results: Of the 25 ASDs, 11 (44%) were circular, 6 (24%) were oval, and 8 (32%) were complex in shape. The mean maximum ASD diameter and mean ASD area measured by 3D TEE were significantly larger than the maximal dimension and area by 2D TEE (Table⇓). Follow-up echocardiograms were available in 17 patients. Eight patients had residual right to left shunting one month after ASD closure. ASD area by 3D TEE was 56% (±33) larger than by 2D TEE in patients with reisdual shunting, whereas the ASD area by 3D TEE was 3% (±45) larger than by 2D TEE in patients without residual shunting (p=0.01).
Conclusions: ASDs were often oval or complex in shape. ASD diameter and area were larger when measured with real-time 3D TEE compared to multiplane 2D TEE. Patients with residual right to left shunting one month after transcatheter ASD closure had a significantly larger discrepancy between the ASD area measured by 3D and 2D imaging compared to patients without residual shunting.