Atrial fibrillation induced by inappropriate reactive antitachycardia pacing due to far field R wave oversensing: A case report

Abstract

An 89-year-old man with an intermittent 2:1 second-degree atrioventricular block received a permanent pacemaker (Medtronic Azure XT DR; Medtronic Inc., Minneapolis, MN, USA). Reactive antitachycardia pacing (ATP) was engaged in all transmissions 3 weeks later. Intracardiac recordings revealed a far-field R wave (FFRW) oversensing, occurring between atrial waves and premature atrial contractions. This event triggered the delivery of reactive ATP, which induced atrial fibrillation. A 79-year-old man underwent permanent pacemaker implantation for an intermittent complete atrioventricular block. One month after implantation, reactive ATP was initiated. The atrial electrogram of intracardiac recordings revealed one being a spontaneous P wave and the other an oversensed R wave. The criterion for an atrial tachycardia was fulfilled, and the device initiated reactive ATP. As a result, atrial fibrillation was induced by inappropriate reactive ATP. It was difficult to completely avoid inappropriate reactive ATP. Finally, we discontinued reactive ATP. The two cases presented in this study demonstrate the possibility of inappropriate reactive ATP due to FFRW oversensing, with the inappropriate reactive ATP inducing atrial fibrillation. All patients treated with reactive ATP should be carefully assessed for the presence of FFRW oversensing during pacemaker implantation and during the follow-up period. Learning objectiveWe present two cases of inappropriate reactive ATP caused by far-field R-wave oversensing. Inappropriate reactive ATP has not been previously reported. Therefore, we suggest that all patients provided with a DDD pacemaker should be carefully assessed for the presence of FFRW oversensing during pacemaker implantation and during the follow-up period. Remote monitoring enables very early detection of inappropriate reactive ATP delivery for rapid implementation of preventive measures.