title: On-line vectorcardiography during elective coronary angioplasty indicates procedure-related myocardial infarction.
abstract: BACKGROUND
  Increased creatine kinase concentrations after elective percutaneous transluminal coronary angioplasty (PTCA) have been shown to be associated with increased late cardiac mortality.
  
  
  OBJECTIVE
  To evaluate the potential of continuous on-line vectorcardiography during elective PTCA to identify procedure-related myocardial infarction.
  
  
  METHODS
  Patients (n = 192, ages 58 +/- 10 years), treated with elective and initially successful PTCA, were studied using vectorcardiogram (VCG) recordings. VCG monitoring was started 5 min before start of the PTCA and was carried out during the entire procedure, for at least 30 min after the first balloon inflation. ST-segment vector magnitude (ST-VM) and ST-segment change vector magnitude (STC-VM) were monitored.
  
  
  RESULTS
  Fifteen (7.8%) procedure-related myocardial infarctions occurred. Indicators of procedure-related myocardial infarction were maximum value of ST-VM (P < 0.001) and STC-VM (P < 0.001), total ischemic time of all ST-VM episodes (P < 0.001) and STC-VM episodes (P < 0.001). The variable most closely related to a procedure-related myocardial infarction was the maximum STC-VM value during the procedure. With an optimized cutoff value, maximum STC-VM predicts a procedure-related myocardial infarction with a sensitivity of 93%, a specificity of 59% and a negative predictive value of 99%. Patients who had a stent implanted had significantly greater VCG values (P < 0.05-P < 0.001) than the group without a stent. There was a trend (P < 0.06) to a relation between increased creatine kinase concentration and stent implantation. In patients both with and without an implanted stent, greater STC-VM values were associated with procedure-related myocardial infarction (P < 0.01).
  
  
  CONCLUSIONS
  Continuous VCG monitoring during elective PTCA is a promising method for immediate detection of patients at increased risk of procedure-related myocardial infarction.
authors.affiliation: Department of Cardiology, Huddinge Hospital, Sweden. jje@cardio.ks.se
authors.forename: J
authors.initials: J
authors.lastname: Jensen
authors.forename: S V
authors.initials: SV
authors.lastname: Eriksson
authors.forename: B
authors.initials: B
authors.lastname: Lindvall
authors.forename: P
authors.initials: P
authors.lastname: Lundin
authors.forename: C
authors.initials: C
authors.lastname: Sylvén
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000792:Angiography; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D003327:Coronary Disease / Q000628:therapy*; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology*; D012372:ROC Curve; D012044:Regression Analysis; D018570:Risk Assessment; D014672:Vectorcardiography