Association between PR Interval, First‐degree atrioventricular block and major arrhythmic events in patients with Brugada syndrome – Systematic review and meta‐analysis

Abstract

Background Risk stratification in patients with asymptomatic Brugada Syndrome is challenging, and despite recent advances, there is no clear evidence. The first‐degree atrioventricular block was hypothesized to be a predictor of arrhythmic events. Measurement of the PR interval and diagnosing atrioventricular block from surface ECG is easy, noninvasive, and cost‐effective. We aimed to assess the latest evidence on PR interval or first‐degree atrioventricular block and major arrhythmic events related to Brugada Syndrome. Methods We performed a comprehensive search in PubMed for “atrioventricular block” OR “PR interval” and “Brugada syndrome.” We included studies that have a component of PR interval and/or first‐degree atrioventricular block and major arrhythmic events related to Brugada Syndrome including syncope/VT/VF/appropriate ICD shocks/ICD implantation. Results We included 1526 subjects from 7 studies. Pooled mean difference of PR interval in 4 studies showed a significant difference [MD 10.77 ms (2.97‐18.57) P = 0.007, moderate‐high heterogeneity I2 = 53% P = 0.08]. On sensitivity analysis by removing a study, it became MD 6.50 ms [1.97‐11.03], P = 0.005, heterogeneity I2 = 0% P = 0.52. Indicating that PR interval was prolonged by small margin. Pooled analysis of the association between a first‐degree atrioventricular block and major arrhythmic events was significant [OR 3.33 (2.02‐5.50) P < 0.001, low heterogeneity I2 = 0% P = 0.57]. Conclusion First‐degree AV block is associated with more frequent major arrhythmic events in Brugada syndrome patients. PR interval seemed to be prolonged but is yet to be determined whether the PR interval association is still significant if it did not cross the first‐degree AVB threshold.

Predictors of late arrhythmic events after generator replacement in Brugada syndrome treated with prophylactic ICD

“…Recently, our study group, for the first time, demonstrated that first-AV block was an independent predictor of malignant arrhythmic events (18). A more recent meta-analysis by Pranata et al confirms that first-degree AV block is associated with more frequent major arrhythmic events in BrS patients (41). In the present study, we found that among ECG abnormalities, patients who experienced malignant arrhythmic events after GR had more often conduction abnormalities including first-degree AV block at baseline (P = 0.04).…”

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

“…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 ].…”

“… Overview of pathomechanisms involved in Brugada syndrome [ 9 , 10 , 11 , 12 , 21 , 22 , 24 , 25 , 26 , 27 ]. Abbreviations: AT—antithrombin; BrS—Brugada syndrome; Ca 2+ —calcium; ECG—electrocardiogram; K + —potassium; ICD—implantable cardioverter–defibrillator; Na + —sodium; SCD—sudden cardiac death; SCN5A—sodium voltage-gated channel alpha subunit 5; RV—right ventricle; RVOT—right ventricular outflow tract; VF—ventricular fibrillation; VT—ventricular tachycardia.…”

Electrocardiographic Markers Indicating Right Ventricular Outflow Tract Conduction Delay as a Predictor of Major Arrhythmic Events in Patients With Brugada Syndrome: A Systematic Review and Meta-Analysis

“…Hence, several studies investigated the association between several ECG markers and major arrhythmic events (MAE) in BrS patients to predict the likelihood of SCD and VTA events. Several meta-analyses revealed that first-degree atrioventricular block, fragmented QRS, wide QRS complex, early repolarization, especially in the inferolateral region, atrial fibrillation, Tpeak-Tend dispersion, Tpeak-Tend interval, and (Tpeak-Tend)/QTc ratio were significantly associated with a higher risk of MAE in BrS patients (8)(9)(10)(11)(12)(13)(14).…”