Inappropriate shocks from a transvenous implantable defibrillator caused by atrial fibrillation and a missed atrial septal defect in a patient with a modified Bentall procedure

Abstract Background Inappropriate shocks have been reported in ∼1/3 of patients with implantable cardiac defibrillators (ICDs). We report an unusual case of inappropriate ICD shocks due to atrial fibrillation (AF) caused by a missed atrial septal defect (ASD) in a patient with a modified Bentall procedure. Case summary A 67-year-old Caucasian male, with an ICD and a history of a modified Bentall procedure 24 years ago, reported to our outpatient clinic with recurrent inappropriate ICD shocks due to episodes of fast AF. The transthoracic echocardiographic exam revealed two large aneurysms at the ostia of the coronary arteries. We performed further evaluation with transoesophageal echocardiogram and computed tomography (CT) angiography. The aneurysms measured on CT were 3.14 cm × 2.29 cm on the right ostium and 1.9 cm × 0.99 cm on the left. A large secundum type ASD of 1.5 cm, missed in all previous echocardiographic studies, was revealed. The therapeutic options of surgical closure of the ASD and repair of the aneurysms or a more conservative approach with percutaneous closure of the ASD and closer follow-up were discussed with the patient. The patient declined the surgical option due to high complication risk, and closure of the ASD with an Amplatzer device was performed 3 months later. A 3-year follow-up was uneventful. Conclusion It is of major importance to comprehensively and thoroughly assess patients before and after a surgical intervention to not miss other treatable conditions preoperatively and complications in the postoperative period.