High-density epicardial mapping in Brugada syndrome: Depolarization and repolarization abnormalities

• Published in: Heart rhythm Vol. 19; no. 3; pp. 397 - 404
• Main Authors: Pannone, Luigi, Monaco, Cinzia, Sorgente, Antonio, Vergara, Pasquale, Calburean, Paul-Adrian, Gauthey, Anaïs, Bisignani, Antonio, Kazawa, Shuichiro, Strazdas, Antanas, Mojica, Joerelle, Lipartiti, Felicia, Al Housari, Maysam, Miraglia, Vincenzo, Rizzi, Sergio, Sofianos, Dimitrios, Cecchini, Federico, Osório, Thiago Guimarães, Paparella, Gaetano, Ramak, Robbert, Overeinder, Ingrid, Bala, Gezim, Almorad, Alexandre, Ströker, Erwin, Pappaert, Gudrun, Sieira, Juan, Brugada, Pedro, La Meir, Mark, Chierchia, Gian Battista, de Asmundis, Carlo
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2022
• Subjects: Ajmaline - pharmacology; Brugada syndrome; Brugada Syndrome - diagnosis; Electrocardiographic imaging; Electrocardiography - methods; Epicardial Mapping - methods; High-density mapping; Humans; Retrospective Studies; Sudden cardiac death; Ventricular tachycardia ablation; Ventricular tachycardia ablation; Brugada syndrome; Sudden cardiac death; High-density mapping; Electrocardiographic imaging
• ISSN: 1547-5271; 1556-3871
• DOI: 10.1016/j.hrthm.2021.09.032

The pathogenesis of Brugada syndrome (BrS) and consequently of abnormal electrograms (aEGMs) found in the epicardium of the right ventricular outflow tract (RVOT-EPI) is controversial. The purpose of this study was to analyze aEGM from high-density RVOT-EPI electroanatomic mapping (EAM). All patients undergoing RVOT-EPI EAM with the HD-Grid catheter for BrS were retrospectively included. Maps were acquired before and after ajmaline, and all patients had concomitant noninvasive electrocardiographic imaging with annotation of RVOT-EPI latest activation time (RVOTat). High-frequency potentials (HFPs) were defined as ventricular potentials occurring during or after the far-field ventricular EGM showing a local activation time (HFPat). Low-frequency potentials (LFPs) were defined as aEGMs occurring after near-field ventricular activation showing fractionation or delayed components. Their activation time from surface ECG was defined as LFPat. Fifteen consecutive patients were included in the study. At EAM before ajmaline, 7 patients (46.7%) showed LFPs. All patients showed HFPs before and after ajmaline and LFPs after ajmaline. Mean HFPat (134.4 vs 65.3 ms, P <.001), mean LFPat (224.6 vs 113.6 ms, P <.001), and mean RVOTat (124.8 vs 55.9 ms, P <.001) increased after ajmaline. RVOTat correlated with HFPat before (ρ = 0.76) and after ajmaline (ρ = 0.82), while RVOTat was shorter than LFPat before (P <.001) and after ajmaline (P <.001). BrS patients with history of aborted sudden cardiac death had longer aEGMs after ajmaline. Two different types of aEGMs are described from BrS high-density epicardial mapping. This might correlate with depolarization and repolarization abnormalities. [Display omitted]