Main characteristics and mode of initiation of spontaneous ventricular tachyarrhythmias in patients with Brugada syndrome (START-BRS)
A Milman, K Nademanee, T Kamakura, G Marcus, L Pannone, E Behr, L Calo, F Migliore, J Tfelt-Hansen, M Laredo, D Viskin, E Anter, B BelhassenAbstract
Background
Data on spontaneous initiation of ventricular arrhythmia (VTA) in patients with Brugada syndrome (BrS) exhibiting polymorphic (PVT) or monomorphic (MVT) ventricular tachycardia are limited.
Objectives
Compare the clinical profile and mode of initiation of PVT and MVT in BrS patients.
Methods
Retrospective multicenter registry of 146 BrS patients from 28 centers with documented VTA initiation recorded by ICD (95%) or ECG (5%). A total of 219 VTAs (1.53 per patient) were analysed. VTA initiation was classified using predefined electrocardiographic criteria.
Results
PVT was observed in 81.5% of patients, MVT in 15.8%, and both in 2.7%. Patients with MVT were older and more frequently White and predominantly exhibited drug-induced Brugada ECG. Pause-dependent initiation occurred in ~25% of PVT and ~33% of MVT episodes. Coupling intervals initiating PVT were significantly shorter than for MVT (median 367 vs. 385 ms; p<0.001), with lower prematurity index and shorter early arrhythmia cycle lengths. Antecedent PVCs were present in ~43% of both VTA types, commonly sharing morphology with initiating PVC. Pathogenic/likely pathogenic SCN5A variant prevalence did not differ between groups.
Conclusions
In this largest analysis of spontaneous VTA onset in BrS, MVT occurred in a substantial minority and associated with older age, White ethnicity and drug-induced ECG pattern. Initiation patterns were broadly similar across arrhythmia types, although PVT was preceded by shorter-coupled PVCs and faster VTA rates. These findings refine the clinical and electrophysiologic characterization of BrS-related arrhythmias and delineate distinct features of PVT and MVT initiation.