Background: The effect of the atrial septal defect (ASD) shape on ASD size measurements remains unclear. We assessed the relationships between the stretched balloon diameter (SBD) and the diameters measured using two-dimensional and three-dimensional (3D) transesophageal echocardiography (TEE) and evaluated the effect of ASD shape on these relationships in patients with secundum ASD.
Methods: We prospectively enrolled 107 consecutive patients who underwent transcatheter closure of ASD. The SBDs and ASD diameters on two-dimensional and 3D-TEE were measured. The circular index of the ASD was defined as the ratio of the maximal diameter to the minimal diameter on the 3D-TEE image. All patients were clinically followed up for a median of 1.3 months after the procedure.
Results: The correlations and agreements between measurements were significantly better in patients with a round (circular index less than 1.5) than with an oval ASD. The differences between the SBDs and maximal diameter on 3D-TEE images were significantly smaller in patients with a large oval ASD than in the other patients. The differences between the size of the devices finally implanted and maximal diameter on 3D-TEE images were smaller in patients with a large oval than with a round ASD. On multivariate linear regression analysis, a formula of the relationship between the finally selected device size and 3D-TEE parameters was constructed: device size = 0.964 × maximal diameter on 3D-TEE image - 2.622 × circular index + 7.084. No major complications, including device embolization, developed during follow-up.
Conclusions: The relationships between the SBDs and maximal diameters measured on two-dimensional and 3D-TEE images are influenced by the ASD shape and size. Therefore, the ASD shape, as well as the size, should be considered when the device size is determined without SBD measurement.
Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.