Myocardial ischemic hyperacute T-wave oversensing leading to a defibrillator shock storm.

Appropriate sensing is essential for the normal functioning of an implantable cardioverter defibrillator (ICD). T-wave oversensing is a potential clinical problem in ICD patients that may result in inappropriate shocks. Oversensing may have various underlying causes and can be treated with noninvasive or invasive means. We present the case of a 45-year-old man presenting with shock storm as a result of T-wave oversensing. Workup revealed a hemodynamically significant stenosis of the left anterior descending artery treated with percutaneous coronary intervention and drug-eluting stent placement. This resulted in the resolution of T-wave missensing and restoration of normal ICD functioning.