The interventional catheterization allows the percutaneous treatment of congenital heart diseases as the atrial septal defect (ASD). The examination is guided by the X-rays with stochastic side effects worrying at the child's. The software "Echonavigator" allows to merge the ultrasound image and fluoroscopic. This innovative software facilitates the procedures and reduce the irradiation time in some adult procedures.

The aim of this study was to validate the image fusion in children.

The software "Echonavigator" will be used after the introduction of the percutaneous closure of ASD prosthesis. The image fusion on fluoroscopy will then be applied and the bias between the generated ultrasound image and the X-ray view of the prosthesis will be measured. The center marker visible prosthesis ultrasound and fluoroscopy used as a reference marker.

Inclusion Criteria:

• Weight higher than or equal to 20 kg
• Presence of an ostium secundum atrial septal defect diagnosed by transthoracic echocardiography and associated with a shunt from left to right evidenced by the significant dilation of the right cavities liable to a closure
• The ASD should have an anatomy allowing percutaneous closure according to international recommendations

Exclusion Criteria:

• Children with contraindication to transesophageal ultrasound according to international recommendations
• ADS with minor shunt without indication of closure
• Refusal to participate in the study expressed by parental authority