title: Inappropriate shocks from a subcutaneous implantable cardioverter-defibrillator due to oversensing during periods of rate-related bundle branch block.
abstract: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is a novel technology with proven efficacy in sudden cardiac death prevention; however, there is a lack of long-term safety data. We describe the case of a 55-year-old female patient implanted with an S-ICD due to idiopathic ventricular fibrillation, who subsequently presented with inappropriate shocks leading to ventricular fibrillation that was successfully terminated by another shock. Inappropriate shocks were due to intermittent T wave oversensing during periods of rate-dependent right bundle branch block. Assessment of the S-ICD electrograms during an exercise test allowed successful reprogramming of the device׳s sensing vector with no further events.
authors.affiliation: Cardiology Department, John Radcliffe Hospital, Oxford University Hospitals, NHS Foundation Trust, Headley Way, Oxford OX3 9DU, United Kingdom; Cardiology Department, Centro Hospitalar do Porto, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal.
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Sousa
authors.affiliation: Cardiology Department, John Radcliffe Hospital, Oxford University Hospitals, NHS Foundation Trust, Headley Way, Oxford OX3 9DU, United Kingdom.
authors.forename: Tim
authors.initials: T
authors.lastname: Betts
keywords: Bundle branch block; Implantable defibrillator; Inappropriate shock; Oversensing; Ventricular fibrillation