Late complete atrioventricular block after closure of an atrial septal defect with a gore septal occluder (GSO™)

Temporary intermittent complete heart block (CHB) occurred the day after interventional closure of an ASD with a 30 mm Gore Septal Occluder (GSO™) in a 2 years and 11-month-old female. CHB disappeared without further treatment and stable sinus rhythm recovered within 3 days. Only short episodes of 2nd degree AV-block (Wenckebach periodicity) at rare intervals were documented in Holter-monitors the following 2 months. Eleven months after device implantation the patient suffered from long lasting episodes of CHB. Surgical removal of the device resulted in incomplete recovery of AV-conduction. Histopathological work-up of the explanted GSO showed complete endothelialization of the device and regular scar formation. One year after surgery, the child had sinus rhythm during daytime but needed VVI-pacing while sleeping. Young age, inferior localization of the defect, and use of a large device have been individual risk factors for CHB in this patient. Clinical course and histologic findings indicate that mechanical compression was the only cause for CHB. The cumulative number of reports of CHB after use of different ASD-devices supports the recommendation to postpone the intervention in asymptomatic patients to preschool-age. Early removal of a pushing device may increase the chance of complete recovery from CHB.