Spectral Analysis of the QT Interval Increases the Prediction Accuracy of Clinical Variables in Brugada Syndrome

Abstract

(1) Background: The clinical management of Brugada Syndrome (BrS) remains suboptimal. (2) Objective: To explore the role of standard electrocardiogram (ECG) spectral analysis in diagnosis and risk stratification. (3) Methods: We analyzed 337 patients—43 with a spontaneous type I ECG pattern (Spont-BrS), 112 drug induced (Induct-BrS), and 182 with a negative response to the drug challenge (negative responders (NR)). ECGs were processed using the wavelet transform (high frequency: 85 to 130 Hz). (4) Results: The power of the high-frequency content in the ST segment (Total ST Power; nV2Hz−1103) was higher in BrS compared with NR patients (Spont-BrS: 28.126 (7.274–48.978) vs. Induc-BrS: 26.635 (15.846–37.424) vs. NR: 11.13 (8.917–13.343); p = 0.002). No differences were observed between ECG patterns in BrS patients. However, the Total ST Power of the type II or III ECG in NR patients was lower than in the same ECG patterns recorded from BrS patients (BrS: 31.07 (16.856–45.283); vs. NR: 10.8 (7.248–14.352) nV2Hz−1103; p = 0.007). The Total ST Power, age, and family history of BrS were independent predictors of positive responses to drug testing. Comparing models with versus those without Total ST Power, the area under the received operator curve (ROC) curve increased (with 0.607 vs. without 0.528, p = 0.001). Only syncope was associated with an increased risk (follow-up 55.8 ± 39.35 months). However, the area under the ROC curve increased significantly when the Total ST Power was included as a covariate (with 0.784 vs. without 0.715, p = 0.04). (5) Conclusions: The analysis of the high-frequency content of ECG signals increases the predictive capability of clinical variables in BrS patients.

Does the Age of Sudden Cardiac Death in Family Members Matter in Brugada Syndrome?

“…A total of 22 (20 cohorts and 2 case‐control) studies from 27 countries (95 studied centers) involving 3386 patients with BrS during the study period of 2004–2019 were included in our meta‐analysis. 2 , 8 , 31 The ages of cut point of SCD among family members in different studies were >45 years old, 12 <50 years old, 13 <45 years old, 8 , 14 , 15 , 16 , 17 , 20 , 21 , 24 , 29 <40 years old, 19 , 22 and <35 years old. 29 a Nine studies did not report age of cut point of SCD among family members.…”

“…Among the 12 studies that defined a family history of SCD <45 years of age (9 studies used 45 years old, 2 , 8 , 14 , 15 , 16 , 17 , 20 , 21 , 24 2 studies used 40 years old, 19 , 22 and 1 study used 35 years old 29 as ages of cut point), the majority (8 of 12) showed an increased risk of MAE (OR, >1.0) 8 , 15 , 16 , 17 , 20 , 21 , 22 , 29 (Figure 3 ); of the 8 studies, 3 studies 15 , 20 , 29 showed the associations were statistically significant.…”

“…None of the results was significantly altered in the overall analysis (Figure S9 ). However, sensitivity analysis of younger than 45 years old showed that the results would become significant if Probst et al, García‐Iglesias et al, or Nagase et al 2 , 14 , 24 were omitted (Figure S10A ). Sensitivity analysis of younger than 40 years old also showed that the results would become nonsignificant if Migliore et al or Siera et al 22 , 29 were omitted (Figure S10B ).…”

“…Positive family history was defined as at least 1 first‐ or second‐degree relative who had sudden unexplained death, sudden cardiac death (SCD), or sudden cardiac arrest or as defined in each study ( Table ). 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 …”

Type of syncope and outcome in Brugada syndrome: A systematic review and meta‐analysis

“…In the overall analysis, a history of syncope was significantly associated with an increased risk of MAE in patients with Brugada syndrome (pooled OR, 3.90; 95% CI, 2.22–6.85; p < .001, I 2 = 76.0%). Results from each study were mixed, with ten studies 4 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 reporting the significant association between the history of syncope and risk of MAE, while the other eight studies 12 , 21 , 22 , 23 , 24 , 25 , 26 , 27 did not find the association to be statistically significant. Only two studies compared outcomes by syncope type 12 , 25 (Table 1 ).…”