Non-invasive assessment of the arrhythmogenic substrate in Brugada syndrome using signal-averaged electrocardiogram: clinical implications from a prospective clinical trial

Europace. 2019 Dec 1;21(12):1900-1910. doi: 10.1093/europace/euz295.

Abstract

Aims: Brugada syndrome (BrS) represents a major cause of sudden cardiac death in young individuals. The risk stratification to forecast future life-threatening events is still controversial. Non-invasive assessment of late potentials (LPs) has been proposed as a risk stratification tool. However, their nature in BrS is still undetermined. The purpose of this study is to assess the electrophysiological determinants of non-invasive LPs.

Methods and results: Two hundred and fifty consecutive patients with (Group 1, n = 96) and without (Group 2, n = 154) BrS-related symptoms were prospectively enrolled in the registry. Signal-averaged electrocardiogram (SAECG) was performed in all subjects before undergoing epicardial mapping. Group 1 patients exhibited larger arrhythmogenic substrates (AS; 5.8 ± 2.8 vs. 2.6 ± 2.1 cm2, P < 0.001) with more delayed potentials (220.4 ± 46.0 vs. 186.7 ± 42.3 ms, P < 0.001). Late potentials were present in 82/96 (85.4%) Group 1 and in 31/154 (20.1%) Group 2 individuals (P < 0.001). Patients exhibiting LPs had more frequently a spontaneous Type 1 pattern (30.1% vs. 10.9%, P < 0.001), SCN5A mutation (34.5% vs. 21.2%, P = 0.02), and exhibited a larger AS with longer potentials (5.8 ± 2.7 vs. 2.2 ± 1.7 cm2; 231.2 ± 37.3 vs. 213.8 ± 39.0 ms; P < 0.001, respectively). Arrhythmogenic substrate dimension was the strongest predictor of the presence of LPs (odds ratio 1.9; P < 0.001). An AS area of at least 3.5 cm2 identified patients with LPs (area under the curve 0.88, 95% confidence interval 0.843-0.931; P < 0.001) with a sensitivity of 86%, specificity 88%, positive predictive value 85%, and negative predictive value 89%.

Conclusion: The results of this study support the role of the epicardial AS as an electrophysiological determinant of non-invasive LPs, which may serve as a tool in the non-invasive assessment of the BrS substrate, as SAECG-LPs could be considered an expression of the abnormal epicardial electrical activity.

ClinicalTrials.gov number (NCT02641431; NCT03106701).

Keywords: Arrhythmogenic substrate; Brugada syndrome; Epicardial ablation; Late potentials; Signal-averaged electrocardiogram.

MeSH terms

  • Action Potentials*
  • Adolescent
  • Adult
  • Brugada Syndrome / diagnosis
  • Brugada Syndrome / physiopathology*
  • Brugada Syndrome / therapy
  • Death, Sudden, Cardiac / prevention & control*
  • Defibrillators, Implantable*
  • Electrocardiography / methods*
  • Epicardial Mapping / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Risk Assessment
  • Signal Processing, Computer-Assisted*
  • Tachycardia, Ventricular / physiopathology*
  • Tachycardia, Ventricular / therapy
  • Ventricular Fibrillation / physiopathology*
  • Ventricular Fibrillation / therapy
  • Young Adult

Associated data

  • ClinicalTrials.gov/NCT02641431
  • ClinicalTrials.gov/NCT03106701