title: Difference in the Clinical Characteristics of Ventricular Fibrillation Occurrence in the Early Phase of an Acute Myocardial Infarction Between Patients With and Without J Waves.
abstract: BACKGROUND
  We recently showed that the presence of J waves increases the risk of ventricular fibrillation (VF) occurrence in the early phase of an acute myocardial infarction (AMI). This study aimed to evaluate the clinical characteristics of VF occurrences in the early phase of an AMI between patients with and without J waves.
  
  
  RESULTS
  This retrospective, observational study included 281 consecutive patients with an AMI (69 ± 12 years; 207 men) in whom 12-lead ECGs before AMI onset could be evaluated. The patients were classified based on a VF occurrence <48 hours after AMI onset and the presence of J waves. J waves were electrocardiographically defined as an elevation of the terminal portion of the QRS complex of >0.1 mV from baseline in at least 2 contiguous inferior or lateral leads. VF occurred in 24 patients, and J waves were present in 37. VF occurrence was more prevalent in the patients with than without J waves (27% vs. 6%; P < 0.001). Among the 244 patients without J waves, peak creatine kinase level (P < 0.01), number of diseased coronary arteries (P < 0.01), and male sex (P < 0.05) were higher in the patients with than without VF occurrence. However, among the 37 patients with J waves, there was no significant difference in these variables. There was no association between the location of J waves and the infarct area.
  
  
  CONCLUSIONS
  In patients with AMI, those with J waves were more likely to develop VF and less likely to have high-risk clinical characteristics than those without J waves.
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Naruse
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nogami
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Harimura
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Mayu
authors.initials: M
authors.lastname: Ishibashi
authors.affiliation: Cardiovascular Division, Tsukuba Medical Center Hospital, Tsukuba, Ibaraki, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Noguchi
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sekiguchi
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Sato
authors.affiliation: Cardiovascular Division, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Aonuma
mesh_terms: D000200:Action Potentials; D000368:Aged; D000369:Aged, 80 and over; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology
keywords: ECG; J-wave; acute myocardial infarction; early repolarization; percutaneous coronary intervention; ventricular fibrillation