Abstract 15748: Failure of Subcutaneous Implantable Cardioverter Defibrillator in a Patient With Arrhythmogenic Right Ventricular Cardiomyopathy

• Published in: Circulation (New York, N.Y.) Vol. 142; no. Suppl_3 Suppl 3; p. A15748
• Main Authors: Desai, Anish K, Glover, Annie, Krebsbach, Angela, Henrikson, Charles
• Format: Journal Article
• Language: English
• Published: by the American College of Cardiology Foundation and the American Heart Association, Inc 17.11.2020
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.142.suppl_3.15748

IntroductionThe subcutaneous ICD is an attractive option in ARVC patients as they rarely require pacing, it preserves vascular access, and it avoids the long-term morbidity related to intravascular lead placement. However, the limitations of the S ICD have not been fully demarcated by clinical trials.CaseAfter her father presented with a cardiac arrest, a 16-year-old female was diagnosed with ARVC on MRI after initially presenting with palpitations. This was corroborated via genetic testing, and an S ICD was placed after she passed pre-implant screening. Initially she did well, but she suffered inappropriate shocks approximately seven months after implant, in the setting of “hugging her boyfriend”. Interrogation revealed apparent noise, which was felt to be most likely due to lead fracture or possibly generator malfunction. At reoperation, first her lead was replaced, but continued noise was demonstrated intra-operatively, and thus her generator was also replaced. However, she was found again to have noise in each vector causing recurrent inappropriate shocks. Further testing ultimately determined that the noise was due to myopotentials, which were present in all vectors and unable to be programmed around. Ultimately, the S ICD was removed and replaced with a transvenous device.DiscussionWhile the S ICD is an attractive option in ARVC patients, the limitations of the technology must be acknowledged. The far-field nature of the sensing algorithm in the S ICD leads to a risk of myopotential oversensing. If this occurs, sometimes the system cannot be salvaged and the patient must be converted to a transvenous system. Recognizing this at the initial presentation with inappropriate shocks can avoid unsuccessful attempts at S ICD system modification and morbidity from future inappropriate shock events.