Occluder Size Determination in Transcatheter Closure of Ostium Secundum Atrial Septal Defect Based on Three-Dimensional Echocardiography Assessment

A total of 50 consecutive patients eligible to percutaneous ASD II closure will be enrolled in the study. 3D-TEE will be performed in the diagnostic process; the images will be recorded for further investigation, however, measurments of the defect will not be taken until after the procedure. Traditional 2D-TEE together with balloon-sizing assessment of the defect will be performed in enrolled patients in order to chose a device. Control transthoracic echocardiography (TTE) will be provided twice to evaluate the outcome of transcatheter treatment: 1 day after the procedure and 6-12 months later. The previously obtained 3D images will be retrospectively assessed by 2 independent investigators excluded from the interventionalists' team. Maximum and minimum diameter, perimeter and area of the defect will be measured to propose the assumed optimal occluder size. Correlation between proposed occluder size and the device used during the procedure will be statistically analyzed.