title: Electrocardiographic findings during balloon angioplasty of the left circumflex coronary artery - influence of location of the ischemic segments with respect to the obtuse margin of the left ventricle.
abstract: Acute left circumflex coronary artery (LCx) occlusion is not easily detected by the standard 12-lead electrocardiogram (ECG).
  
  
  
  In 16 patients continuous ECG recording was performed during balloon occlusion. The treated lesions were divided into proximal and distal based on the location of the ischemic segments with respect to the left obtuse margin of the heart.
  
  
  
  Mean ΔST (=ST amplitude during inflation - pre-inflation ST) ≥0.5mm in both leads I and aVL predicted a proximal occlusion site with sensitivity of 62.5% (95% confidence interval [CI] 24.9-91.5%), specificity 100% (95% CI 63.1-100%), positive predictive value 100% (95% CI 47.8-100%), and negative predictive value 72.7% (95% CI 39-94%). In lead III, mean ΔST was +0.3mm in the distal and -0.2mm in the proximal group, respectively (p=0.036).
  
  
  
  ST elevation in leads I and aVL is associated with myocardial ischemia at or proximal to the left obtuse margin.
authors.affiliation: Heart Center, Department of Cardiology, Tampere University Hospital, and School of Medicine, University of Tampere, Finland; Department of Cardiology, Faculty of Medicine, Zagazig University, Egypt.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Abdelwahed
authors.affiliation: Heart Center, Department of Cardiology, Tampere University Hospital, and School of Medicine, University of Tampere, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Eskola
authors.affiliation: Heart Center, Department of Cardiology, Tampere University Hospital, and School of Medicine, University of Tampere, Finland; Department of Internal Medicine, Savonlinna Central Hospital, Finland.
authors.forename: Petteri
authors.initials: P
authors.lastname: Kosonen
authors.affiliation: Heart Center, Department of Cardiology, Tampere University Hospital, and School of Medicine, University of Tampere, Finland.
authors.forename: Heikki
authors.initials: H
authors.lastname: Mäkynen
authors.affiliation: Heart Center, Department of Cardiothoracic Surgery, Tampere University Hospital, and School of Medicine, University of Tampere, Finland.
authors.forename: Jari
authors.initials: J
authors.lastname: Laurikka
authors.affiliation: School of Health Sciences, University of Tampere, Finland.
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.affiliation: Heart Center, Department of Cardiology, Tampere University Hospital, and School of Medicine, University of Tampere, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Inkovaara
authors.affiliation: The Section of Cardiology, the Department Of Medicine, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Yochai
authors.initials: Y
authors.lastname: Birnbaum
authors.affiliation: Heart Center, Department of Cardiology, Tampere University Hospital, and School of Medicine, University of Tampere, Finland. Electronic address: kjell.nikus@sydansairaala.fi.
authors.forename: Kjell
authors.initials: K
authors.lastname: Nikus
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects* / Q000379:methods; D054059:Coronary Occlusion / Q000175:diagnosis* / Q000601:surgery*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000601:surgery; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000601:surgery*
keywords: Balloon angioplasty; Electrocardiographic; Left circumflex coronary artery; Left ventricle