Background: A secundum atrial septal defect (ASD II) is the most common type of all the communication between atria of the heart. A percutaneous closure of ASD II has been widely applied and appears to be an acceptable alternative to the surgical closure. However, some complications have been reported.
Case Report: We present an 8-year old girl with the congenital heart defect such as ASD II who was referred for further cardiac evaluation and treatment to our department. The girl was qualified for the transcatheter closure of the intraatrial communication with the Cardia device. The ASD was closed with the device of 30 mm in diameter (Cardia 3015). Twenty four hours later during a routine follow-up ecg the complete atrio-ventricular block was found and the patient was treated with parenteral corticosteroids for 5 days and next
with oral corticosteroids for further 3 weeks up to the full recovery of the atrioventricular conduction.
Conclusions: The percutaneous closure of ostium secundum atrial septal defects (ASDs) has been widely accepted and is becoming one of the standard treatments of this malformation. The atrioventricular conduction disturbances are possible but in most cases they are transient.
A corticosteroid therapy should be taken into consideration as the alternative therapy.

Keywords: Heart Septal Defects, Atrial, Cardia