Quantification of Delayed Activation in Right Ventricular Outflow Tract in Brugada Patients

Brugada syndrome is a genetic disease associated with increased incidence of sudden cardiac death.Brugada patients have demonstrated delayed and heterogeneous conduction localized in the epicardial right ventricular outflow tract.Ventricular dyssynchrony in the right ventricular outflow tract constitutes a substrate of ventricular fibrillation.The present work aims to identify delays in the ventricular activation in Brugada patients from 24-hour electrocardiographic monitoring with the high precordial leads configuration.A lead-dependent global activation time is computed, every half hour in each lead, as the time instant along the QRS complex at which 50% of its total energy is reached.The spatial dispersion in activation, T , is defined as the difference between maximum and minimum global activation time values across leads, and it is evaluated every half hour.Brugada patients, especially the symptomatic ones, showed higher spatio-temporal dispersion over the 24 hours in global activation time than controls, indicating delayed and variable ventricular conduction (BrS: T =13[9; 28]ms; Controls: T =8[6; 9]ms, p < 0.01).In conclusion, this metric for quantifying spatial dispersion of ventricular activation not only distinguishes BrS patients but also holds potential for enhancing risk stratification in individuals with conduction disorders through 24-hour electrocardiographic monitoring.