Case report: Atrioventricular block after transcatheter atrial septal closure using the Figulla® Flex II ASD occluder.

We report a 7-year-old male patient who developed severe atrioventricular block after transcatheter closure of the atrial septal defect with an Occlutech Figulla® Flex II ASD occluder (FSO). He had a small aortic rim and the defect measuring 22.3 mm by balloon sizing. When a 24 mm FSO was deployed, he developed Wenckebach second-degree heart block; however, it recovered to sinus rhythm. Hence, the device was implanted. The rhythm deteriorated to a fixed 2:1 heart block within 7 hr. He underwent surgical retrieval of the device and closure of the defect. Intraoperative findings demonstrated the right atrium disk compressing the triangle of Koch, resulting in a small hematoma. The rhythm recovered completely by 7 days after the surgery. Care must be taken when a relatively large device is deployed in a patient with small rims as even "soft and flexible" device like the FSO can injure the endocardium.