Predictors of inappropriate shock in Brugada syndrome patients with a subcutaneous implantable cardiac defibrillator

J Cardiovasc Electrophysiol. 2021 Jun;32(6):1704-1711. doi: 10.1111/jce.15059. Epub 2021 May 5.

Abstract

Background: Subcutaneous implantable cardioverter defibrillators (S-ICDs) avoid complications secondary to transvenous leads, but inappropriate shocks (ISs) are frequent. Furthermore, IS data from patients with Brugada syndrome (BrS) with an S-ICD are scarce.

Objective: We aimed to establish the frequency and predictors of IS in this population.

Methods: We analyzed the clinical and electrocardiographic characteristics, automated screening test data, device programming, and IS occurrence in adult patients with BrS with an S-ICD.

Results: Thirty-nine patients were enrolled (69% male, mean age at diagnosis 46 ± 13 years, mean age at implantation 48 ± 13 years). During a mean follow-up of 26 ± 21 months, 18% patients experienced IS. Patients with IS were younger at the time of diagnosis (36 ± 8 vs. 48 ± 13 years, p = .018) and S-ICD implantation (38 ± 9 vs. 50 ± 23 years, p = .019) and presented with spontaneous type 1 Brugada electrocardiogram pattern more frequently at diagnosis or during follow-up (71% vs. 25%, p = .018). During automated screening tests, patients with IS showed lower QRS voltage in the primary vector in the supine position (0.58 ± 0.26 vs. 1.10 ± 0.35 mV, p = .011) and lower defibrillator automated screening score in the primary vector in the supine (123 ± 165 vs. 554 ± 390 mV, p = .005) and standing (162 ± 179 vs. 486 ± 388 mV, p = .038) positions. Age at diagnosis was the only independent predictor of IS (hazard ratio = 0.873, 95% confidence interval: 0.767-0.992, p = .037).

Conclusion: IS was a frequent complication in patients with BrS with an S-ICD. Younger age was independently associated with IS. A more thorough screening process might help prevent IS in this population.

Keywords: Brugada syndrome; inappropriate shock; subcutaneous implantable cardioverter-defibrillator.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brugada Syndrome* / diagnosis
  • Brugada Syndrome* / therapy
  • Death, Sudden, Cardiac / epidemiology
  • Death, Sudden, Cardiac / etiology
  • Death, Sudden, Cardiac / prevention & control
  • Defibrillators, Implantable* / adverse effects
  • Electrocardiography
  • Female
  • Follow-Up Studies
  • Heart
  • Humans
  • Male
  • Subcutaneous Tissue
  • Treatment Outcome