title: Association of ST segment depression >5 min after exercise testing with severity of coronary artery disease.
abstract: OBJECTIVE
  To determine the association of prolonged ST segment depression after an exercise test with severity of coronary artery disease.
  
  
  METHODS
  A cross sectional study of 100 consecutive patients referred to the cardiology laboratory for stress myocardial perfusion imaging (MPI) conducted between April-August 2008. All selected patients were monitored until their ST segment depression was recovered to baseline. ST segment recovery time was categorized into less and more than 5 minutes. Subsequent gated SPECT-MPI was performed and stratified according to severity of perfusion defect. Association was determined between post exercise ST segment depression recovery time (<5 minutes and >5 minutes) and severity of perfusion defect on MPI.
  
  
  RESULTS
  The mean age of the patients was 57.12 +/- 9.0 years. The results showed statistically insignificant association (p > 0.05) between ST segment recovery time of <5 minutes and >5 minutes with low, intermediate or high risk MPI.
  
  
  CONCLUSIONS
  Our findings suggest that the commonly used cut-off levels used in literature for prolonged, post exercise ST segment depression (>5 minutes into recovery phase) does not correlate with severity of ischaemia based on MPI results.
authors.affiliation: Tabba Heart Institute Karachi.
authors.forename: Ayaz Hussain
authors.initials: AH
authors.lastname: Shaikh
authors.forename: Bashir
authors.initials: B
authors.lastname: Hanif
authors.forename: Adeel M
authors.initials: AM
authors.lastname: Siddiqui
authors.forename: Hunaina
authors.initials: H
authors.lastname: Shahab
authors.forename: Hammad Ali
authors.initials: HA
authors.lastname: Qazi
authors.forename: Iqbal
authors.initials: I
authors.lastname: Mujtaba
mesh_terms: D016009:Chi-Square Distribution; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon