title: Controversial and similar aspects of the Brugada and J wave patterns: The vectorcardiogram point of view-Revision 2.
abstract: The J-wave electrocardiographic patterns include early repolarization (ER) and Brugada syndrome; especially when ER is located in the anteroseptal leads (V1-V3), it can mimic the Brugada syndrome (BrS) ECG pattern and therefore mislead the diagnosis. We aimed to define the vectorcardiographic characteristics of BrS and ER using aspects of QRS complex loop, J-point and ST-segment.
  
  
  
  Vectorcardiographic loops in the transverse plane (TP) of 14 BrS patients and 26 individuals with ER were analyzed and defined, and then a third group of 17 patients with non-characteristic ECG patterns were analyzed and compared with them. All QRS loops showed end-conduction delay (ECD) located in the right posterior-anterior quadrant (BrS) or left posterior-anterior quadrant (ER). In 100% cases a "break" in the QRS loop end, resembling a "nose" identified BrS, and a "fish-hook" shape identified ER. Non-coincidental QRS complex onset-end defined J-point resulting vector. BrS showed a significantly longer end-conduction delay (100% right anterior quadrant), shorter J-point amplitude oriented to the right, and "nose-like" QRS end loop. Analysis of group 3 confirmed the accuracy of the qualitative aspects to distinguish this "atypical" population: "fish-hook" shape of ER in the transverse plane in 6 individuals; and the "nose" shape of BrS in 14 patients, among which 2 patients had both patterns simultaneously.
  
  
  
  Vectorcardiographic characteristics could clearly differentiate BrS from ER qualitatively and quantitatively even in atypical ECGs.
authors.affiliation: Clinical Unit of Electrocardiography-Heart Institute (InCor) from Hospital das Clínicas da Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil. Electronic address: ecg_pastore@incor.usp.br.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Pastore
authors.affiliation: Clinical Unit of Electrocardiography-Heart Institute (InCor) from Hospital das Clínicas da Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Nelson
authors.initials: N
authors.lastname: Samesima
authors.affiliation: Clinical Unit of Electrocardiography-Heart Institute (InCor) from Hospital das Clínicas da Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Horácio G Pereira
authors.initials: HG
authors.lastname: Filho
authors.affiliation: Clinical Unit of Electrocardiography-Heart Institute (InCor) from Hospital das Clínicas da Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: Bruna A
authors.initials: BA
authors.lastname: Madaloso
mesh_terms: D000328:Adult; D000465:Algorithms; D053840:Brugada Syndrome / Q000175:diagnosis*; D000075224:Cardiac Conduction System Disease / Q000175:diagnosis*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014672:Vectorcardiography / Q000379:methods*
keywords: Brugada syndrome; Diagnostic method; Early repolarization; Electrocardiography; J-point; J-wave patterns; Vectorcardiography