Characteristics of patients with Brugada syndrome and monomorphic ventricular tachycardia

Abstract

Background: Brugada syndrome (BrS) is an arrhythmogenic disorder associated with sudden cardiac death primarily owing to ventricular fibrillation (VF). Monomorphic ventricular tachycardias (MVTs) are rarely reported, and little is known about their characteristics.

Objective: This study aimed to evaluate the characteristics of patients with BrS presenting with MVT compared with those with VF.

Methods: We performed a retrospective multicenter study of patients with BrS who received an implantable cardioverter-defibrillator (ICD). Inclusion criteria were (1) the initiation of ventricular arrhythmia on ICD recordings and (2) the absence of antiarrhythmic drugs or previous ventricular ablation. Arrhythmic events were classified as MVT or polymorphic ventricular tachycardia (PVT)/VF (both referred to as VF) according to the guidelines. We analyzed clinical data, characteristics related to arrhythmia initiation, and electroanatomic substrate.

Results: Among 793 patients with BrS with ICDs (44.2 ± 17.7 years, 37.1% women), 54 met the inclusion criteria. ICD recordings showed a total of 47 VF episodes and 27 MVT episodes, overlapping in only 1 patient. Patients with MVT were older at first event (47.7 ± 13.4 vs 40.7 ± 12.6 years, P = .06), had higher QRS duration, more prevalence of syncope, and later recurrences after ICD implantation (median 51 vs 20 months, P = .018). Rapid rhythms (>100 beats/min) were more frequent before MVT than VF (48.1% vs 8.5%, P < .001) with a lower incidence of ectopy (22.2% vs 61.7, P = .001). Abnormal epicardial substrate was broader in patients with MVT in baseline conditions (11.3 ± 5.5 cm² vs 6.8 ± 3.2 cm², P = .006).

Conclusion: VF/PVT and MVT in patients with BrS have distinct clinical presentations. MVT shows a later onset compared with VF/PVT and is associated with a broader substrate area.

Keywords: Brugada syndrome; Implantable cardioverter-defibrillator; Monomorphic ventricular tachycardia; Sudden cardiac death; Ventricular fibrillation.