Sizing of Atrial Septal Defects in Adults

In a retrospective study of 51 consecutive patients undergoing transcatheter closure of secundum type atrial septal defects (ASDs), we examined the reliability of transesophageal echocardiography (TEE) prior to catheterization and compared the diameter with that obtained by balloon measurement during catheterization. The TEE diameter was 16.3 ± 4.6 mm compared with 22.5 ± 6.0 mm for the stretched diameter obtained during catheterization (p < 0.001). There was no gender difference. The degree of left-to-right shunting correlated poorly with the size of the defect. We conclude that although TEE is accurate for diagnosis of an ASD, the measurement of its size to determine the size of the closure device is at best inaccurate.