社団法人日本循環器学会 Circulation journal : official journal of the Japanese Circulation Society 13469843 71 8 1258 1262 2007-07-20 2007-07-20 Endocardial Electrograms From the Right Ventricular Outflow Tract After Induced Ventricular Fibrillation in Patients With Brugada Syndrome Ohkubo,Kimie Watanabe,Ichiro Takagi,Yasuhiro Okumura,Yasuo Ashino,Sonoko Kofune,Masayoshi Kofune,Tatsuya Shindo,Atsushi Sugimura,Hidezou Nakai,Toshiko Kunimoto,Satoshi Kasamaki,Yuji Saito,Satoshi Hirayama,Atsushi Japanese Circulation Society Circulation journal : official journal of the Japanese Circulation Society Background The pathogenesis of Brugada syndrome (BS) is reported to be phase 2 reentry resulting from shortening of the action potential duration at the epicardial site of the right ventricular outflow tract (RVOT). However, several reports have shown a high incidence of ventricular late potentials (LPs) and a high rate of induction of ventricular fibrillation (VF) by programmed ventricular stimulation (PVS) among patients with BS. The aim of this study was to investigate the role of slow conduction for the initiation of VF by PVS in these patients. Methods and Results Endocardial mapping of the RVOT was conducted in 17 patients in whom VF was induced by PVS from the RV apex or RVOT; 11 patients had a positive LP. In 10 patients, RV mapping showed that low-amplitude fragmented and delayed potentials (DPs) were recorded at the RVOT below the pulmonary valve (PV) or between the PV and His bundle electrogram recording site. Electrograms recorded after PVS showed a high incidence of fractionated and disorganized DPs that lead to VF. Conclusions Slow conduction at the RVOT may contribute to the induction of VF by PVS. However, the role of slow conduction in spontaneous VF remains controversial. Ohkubo,Kimie Division of Cardiology, Department of Medicine, Nihon University School of Medicine Watanabe,Ichiro Division of Cardiology, Department of Medicine, Nihon University School of Medicine Takagi,Yasuhiro Division of Cardiology, Department of Medicine, Nihon University School of Medicine Okumura,Yasuo Division of Cardiology, Department of Medicine, Nihon University School of Medicine Ashino,Sonoko Division of Cardiology, Department of Medicine, Nihon University School of Medicine Kofune,Masayoshi Division of Cardiology, Department of Medicine, Nihon University School of Medicine Kofune,Tatsuya Division of Cardiology, Department of Medicine, Nihon University School of Medicine Shindo,Atsushi Division of Cardiology, Department of Medicine, Nihon University School of Medicine Sugimura,Hidezou Division of Cardiology, Department of Medicine, Nihon University School of Medicine Nakai,Toshiko Division of Cardiology, Department of Medicine, Nihon University School of Medicine Kunimoto,Satoshi Division of Cardiology, Department of Medicine, Nihon University School of Medicine Kasamaki,Yuji Division of Cardiology, Department of Medicine, Nihon University School of Medicine Saito,Satoshi Division of Cardiology, Department of Medicine, Nihon University School of Medicine Hirayama,Atsushi Division of Cardiology, Department of Medicine, Nihon University School of Medicine