Accurate measurement of defect size is important in transcatheter closure of atrial septal defect (ASD). We performed this study to analyze the difference between the measured ASD size and balloon occlusive diameter (BOD) by transthoracic (TTE) or transesophageal echocardiography (TEE).

We investigated 78 patients who underwent transcatheter closure of ASD. The defect size and the distance between the surrounding structures were measured by TTE and TEE. The BOD was measured by TEE during cardiac catheterization. Clinical characteristics and echocardiographic data were compared and analyzed.

The difference between BOD and diameter by TTE was 4.8±3.6 mm on short axis view, 5.4±3.2 mm on long axis view. The difference between BOD and diameter by TEE was 3.6±2.2 mm on short axis view, 4.2±3.1 mm on long axis view. The difference between BOD and the diameter of defects on TTE, TEE had statistically significant positive correlations with the age of the patients, distance between the, defect and posterior atrial septal wall, the distance between the defect and the mitral valve leaflet, and the diameter of defects and the length of the atrial septum on TTE ( P <0.05).

BOD of ASD can be estimated by the diameter on TTE and TEE. BOD is expected to measure larger, depending on the size of defects, the distance from surrounding structures and the location of defects on echocardiography. Our data offers important information on details of transcatheter ASD closure which can be helpful in predicting suitability and judging the procedural appropriateness during the procedure.