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

• DOI: 10.1016/j.hrthm.2021.09.032
• Publication Date: 2021-10-01T07:45:36Z
• Authors: Luigi Pannone; Cinzia Monaco; Antonio Sorgente; Pasquale Vergara; Paul-Adrian Calbu...; Anaïs Gauthey; Antonio Bisignani; Shuichiro Kazawa; Antanas Strazdas; Joerelle Mojica; Felicia Lipartiti; Maysam Al Housari; Vincenzo Miraglia; Sergio Rizzi; Dimitrios Sofianos; Federico Cecchini; Thiago Guimarães ...; Gaetano Paparella; Robbert Ramak; Ingrid Overeinder; Gezim Bala; Alexandre Almorad; Erwin Ströker; Gudrun Pappaert; Juan Sieira; Pedro Brugada; Mark La Meir; Gian Battista Chi...; Carlo de Asmundis
• Keywords: Epicardial Mapping; Ajmaline; sudden cardiac death; Electrocardiography; 03 medical and health sciences; 0302 clinical medicine; electrocardiographic imaging; Humans; Brugada syndrome; Ventricular tachycardia ablation; High-density mapping; Brugada Syndrome; Retrospective Studies

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.