title: Role of signal-averaged electrocardiograms for predicting the inducibility of ventricular fibrillation in the syndrome consisting of right bundle branch block and ST segment elevation in leads V1-V3.
abstract: Right bundle branch block and ST segment elevation (RBBB-STE) in the right precordial leads have been reported as a distinct clinical and electrocardiographic syndrome in patients prone to ventricular fibrillation (VF) in the absence of structural heart disease (Brugada syndrome). The purpose of the study was to investigate the role of signal averaged electrocardiogram (SAECG) in identifying patients at high risk among asymptomatic RBBB-STE patients. Thirteen patients with the RBBB-STE ECG were identified. Symptoms were: syncope (n=3, cases 1, 3, and 11), atypical chest pain (n=3, cases 4, 10, and 12) and palpitations (n=2, cases 6, and 7). The other 5 patients were asymptomatic. SAECG and programmed electrical stimulation (PES) were conducted in all patients. Body surface late potentials (LPs) were present in 7 of 13 patients before PES. Vf was induced in 6 of 7 LP positive patients. Vf was induced in 3 of 6 LP negative patients, but LP became positive in 2 of 3 patients in whom Vf was induced. One patient with syncope due to VF (case 1), 1 patient without symptoms who died suddenly during follow up (case 2), and 1 asymptomatic patient (case 9) showed reproducibly positive LP. In a patient (case 9) with positive LP at baseline, LP transiently became negative during follow up. In RBBB-STE patients, reproducibly positive LP is at risk for malignant ventricular arrhythmias and sudden death. Repeated SAECG recording may be useful for screening high-risk patients who should receive electrophysiological study among asymptomatic RBBB-STE patients.
authors.affiliation: Second Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Riko
authors.initials: R
authors.lastname: Masaki
authors.forename: Ichiro
authors.initials: I
authors.lastname: Watanabe
authors.forename: Toshiko
authors.initials: T
authors.lastname: Nakai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kondo
authors.forename: Naohiro
authors.initials: N
authors.lastname: Oshikawa
authors.forename: Hidezou
authors.initials: H
authors.lastname: Sugimura
authors.forename: Kimie
authors.initials: K
authors.lastname: Okubo
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Kojima
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saito
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ozawa
authors.forename: Katsuo
authors.initials: K
authors.lastname: Kanmatsuse
mesh_terms: D000328:Adult; D000368:Aged; D018780:Body Surface Potential Mapping; D002037:Bundle-Branch Block / Q000503:physiopathology* / Q000628:therapy; D002637:Chest Pain / Q000150:complications; D017147:Defibrillators, Implantable; D004558:Electric Stimulation; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013575:Syncope / Q000150:complications; D013577:Syndrome; D014693:Ventricular Fibrillation / Q000503:physiopathology*