A Shocking Case of Far-Field Atrial Oversensing in Giant-Cell Myocarditis

Abstract

We report a unique case of delivery of inappropriate implantable cardioverter-defibrillator therapies related to a “perfect storm”: presence of an integrated lead, insufficient lead slack related to right heart dilation resulting in shock coil misplacement, myocarditis with loss of R waves, and the concomitant occurrence of an incessant atrial tachycardia. ( Level of Difficulty: Advanced. )

Progressive giant cell myocarditis presenting with inappropriate shocks from a subcutaneous defibrillator

“…Furthermore, a reduction in intracardiac R-wave sensing in GCM leading to the delivery of inappropriate shocks has also been reported. 12 …”