title: ST-segment changes in high-resolution body surface potential maps measured during exercise to assess myocardial ischemia: a pilot study.
abstract: BACKGROUND
  The aim of the study was to assess myocardial ischemia by analysis of ST-segment changes in high-resolution body surface potential maps (HR-BSPM) measured at rest and during an exercise stress test.
  
  
  METHODS
  The study was carried out on a group of 28 patients with stable coronary artery disease and 15 healthy volunteers. The HR-BSPM were measured at rest and during the exercise stress test on a supine ergometer. The workload was increased in stages by 25 W every 2 min, beginning at 50 W. The maps of ST-segment depression (ST60) were calculated from time averaged recordings at rest and at maximal workload.
  
  
  RESULTS
  The efficiency in detection of myocardial ischemia was higher for HR-BSPM than for standard 12-lead electrocardiography (ECG) when both methods were evaluated by outcomes of coronarography. The sensitivity of HR-BSPM was 82.4% while for the standard 12-lead ECG exercise stress test it was 58.8%. For some patients significant changes in the ST segment were observed at stress HR-BSPM but were not visible in standard 12-lead ECG recorded under the same conditions.
  
  
  CONCLUSIONS
  Obtained high values of sensitivity and specificity in myocardial ischemia detection suggest that maps of ST60 calculated from HR-BSPM can improve detection of patients with ischemic heart disease in comparison to the standard electrocardiographic exercise stress test examinations.
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Kania
authors.affiliation: I Chair Department of Cardiology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Rajmund
authors.initials: R
authors.lastname: Zaczek
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Heriberto
authors.initials: H
authors.lastname: Zavala-Fernandez
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Janusek
authors.affiliation: Department of Nuclear Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Kobylecka
authors.affiliation: Department of Nuclear Medicine, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Leszek
authors.initials: L
authors.lastname: Królicki
authors.affiliation: I Chair Department of Cardiology, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Opolski
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Roman
authors.initials: R
authors.lastname: Maniewski
keywords: ST segment; body surface potential mapping; coronarography; exercise test