Wide QRS complex and the risk of major arrhythmic events in Brugada syndrome patients: A systematic review and meta‐analysis

Abstract

Background: Brugada syndrome (BrS) is an inherited arrhythmic disease associatedwith an increased risk of major arrhythmic events (MAE). Previous studies reported that a wide QRS complex may be useful as a predictor of MAE in BrS patients. We aimed to assess the correlation of wide QRS complex with MAE by a systematic review and meta-analysis. Methods:We comprehensively searched the databases of MEDLINE and EMBASE from inception to June 2019. Included studies were cohort and case control studies that reported QRS duration and the relationship between wide QRS complex (>120 milliseconds) and MAE (sudden cardiac death, sudden cardiac arrest, ventricular fibrillation, sustained ventricular tachycardia, or appropriate shock). Data from each study were combined using the random-effects model. Results:Twenty-two studies from 2007 to 2018 were included in this metaanalysis involving 4,814 BrS patients. The mean age was 46.1 ± 12.8 years.The patients were predominately men (77.6%). Wide QRS duration was an independent predictor of MAE (pooled risk ratio 1.55, 95% confidence interval:1.04-2.30, P = .30, I 2 = 38.4%). QRS duration was wider in BrS who had history of MAE (weight mean difference = 8.12 milliseconds, 95% confidence interval: 5.75-10.51 milliseconds). Conclusions:Our study demonstrated that QRS duration is wider in BrS who had history of MAE, and a wide QRS complex is associated with 1.55 times higher risk of MAE in BrS populations. Wide QRS complex can be considered for risk stratification

Automated Electrocardiogram Analysis Identifies Novel Predictors of Ventricular Arrhythmias in Brugada Syndrome

“…In BrS, both depolarization and repolarization abnormalities are posited to play important roles in ventricular arrhythmogenesis ( 15 , 16 ). ECG indices related depolarization ( 13 ), such as QRS duration, QRS dispersion, R-wave and S-wave durations have been identified as useful predictors in this condition ( 3 , 17 – 21 ). For Brugada syndrome, QRS vector magnitude was identified as a predictor of ventricular arrhythmias ( 22 ).…”

Pathogenesis and Management of Brugada Syndrome: Recent Advances and Protocol for Umbrella Reviews of Meta-Analyses in Major Arrhythmic Events Risk Stratification

“…However, magnetic resonance imaging in subgroups of patients with BrS revealed enlarged right ventricular (RV) volumes, increased RV outflow tract (RVOT) area, or mild RV wall motion abnormalities [ 16 ]. The pathomechanism observed in BrS patients involves depolarization and repolarization abnormalities, inflammation of myocytes, and fibrosis in RVOT and/or RV [ 9 , 12 ]. A recent study performed on whole hearts from deceased patients, whose SCD was accounted to BrS, showed biventricular myocardial fibrosis, especially in the epicardium of the RVOT [ 17 ].…”

“…For example, excess outflow of potassium current during early repolarization or reduced inward current via calcium channels may contribute to BrS pathophysiology [ 21 ]. The reduced inward current flow of sodium in BrS patients may result in prolonged PR (PQ) interval, first degree atrioventricular block [ 22 ], slow cardiac conduction (intraventricular and His–Purkinje), phase 2 reentry and premature repolarization [ 21 ], low-amplitude and high-frequency electrical activity in RVOT epicardium (late potentials), and ventricular arrhythmias [ 12 , 23 ].…”

“…Prolonged QRS complex duration, >120 milliseconds on standard 12-lead ECG due to slowed depolarization, was more pronounced in BrS patients expressing symptoms and may predict future MAE [ 12 ]. Moreover, T-peak to T-end (Tpe) intervals were identified as novel ECG markers in BrS patients for MAE prediction.…”

“…BrS is approximately nine times more common in males [ 8 , 9 ], and is one of the leading causes of SCD in males below age 40 in southeast Asia [ 10 ]. Patients with BrS are considered symptomatic if they have a history of aborted SCD, ventricular fibrillation (VF), sustained ventricular tachycardia (VT), or syncope [ 11 , 12 ].…”