title: Comparison of high-frequency QRS components and ST-segment elevation to detect and quantify acute myocardial ischemia.
abstract: OBJECTIVE
  This study tests the ability of high-frequency components of the depolarization phase (HF-QRS) vs conventional ST-elevation criteria to detect and quantify myocardial ischemia.
  
  
  METHODS
  Twenty-one patients admitted for elective percutaneous coronary intervention were included. Quantification of the ischemia was made by myocardial scintigraphy. High-resolution electrocardiogram before and during percutaneous coronary intervention was recorded and signal averaged. The HF-QRS were determined within the frequency band 150 to 250 Hz. ST-segment deviation was measured in the standard frequency range (<100 Hz).
  
  
  RESULTS
  HF-QRS criteria were met by 76% of the patients, whereas 38% met the ST-elevation criteria (P = .008). Both HF-QRS reduction and ST elevation correlated significantly with the amount of ischemia (HF-QRS: r = 0.59, P = .005 for extent and r = 0.69, P = .001 for severity; ST elevation: r = 0.49, P = .023 for extent and r = 0.57, P = .007 for severity).
  
  
  CONCLUSIONS
  This study suggests that HF-QRS analysis could provide valuable information both to detect acute ischemia and to quantify myocardial area at risk.
authors.affiliation: Department of Cardiology, Lund University, Lund, Sweden. michael.ringborn@ltblekinge.se
authors.forename: Michael
authors.initials: M
authors.lastname: Ringborn
authors.forename: Jonas
authors.initials: J
authors.lastname: Pettersson
authors.forename: Eva
authors.initials: E
authors.lastname: Persson
authors.forename: Stafford G
authors.initials: SG
authors.lastname: Warren
authors.forename: Pyotr
authors.initials: P
authors.lastname: Platonov
authors.forename: Olle
authors.initials: O
authors.lastname: Pahlm
authors.forename: Galen S
authors.initials: GS
authors.lastname: Wagner
mesh_terms: D000368:Aged; D000465:Algorithms; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity