title: Significance of QRS duration changes in the evaluation of ST-segment depression presenting exclusively during the postexercise recovery period.
abstract: BACKGROUND
  The aim of this study was to evaluate the contribution of QRS prolongation in the diagnosis of coronary artery disease (CAD) in patients with exercise-induced ST-segment depression exclusively during the recovery period.
  
  
  METHODS
  The study population consisted of 107 patients (90 males and 17 females) aged 39-70 (mean 59 +/- 7) years who underwent a treadmill exercise test using Bruce protocol and presented ST-segment depression limited to the recovery period. Angiographic data were available for all studied patients.
  
  
  RESULTS
  Among studied patients, 74 (69%) were found to have hemodynamically significant CAD, while the remaining 33 (31%) had normal coronary arteries. Concomitant QRS prolongation was revealed in 61 (82%) of the patients with angiographically documented CAD, while in 13 (18%) patients QRS duration remained unchanged. On the contrary, only 4 (12%) of the 33 patients with normal coronary arteries showed prolonged QRS duration during ST depression, while in the remaining 29 (88%) QRS duration remained unchanged.
  
  
  CONCLUSIONS
  The evaluation of the concomitant QRS duration changes may discriminate patients with truly ischemia-induced ST-segment depression limited to the recovery period.
authors.affiliation: Department of A' Cardiology Clinic, Medical School of Athens University, Hippokration Hospital, Athens, Greece. chrisfour@altecnet.gr
authors.forename: Andreas P
authors.initials: AP
authors.lastname: Michaelides
authors.forename: Christos A
authors.initials: CA
authors.lastname: Fourlas
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Giannopoulos
authors.forename: Konstantina
authors.initials: K
authors.lastname: Aggeli
authors.forename: George K
authors.initials: GK
authors.lastname: Andrikopoulos
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Tsioufis
authors.forename: Spiros S
authors.initials: SS
authors.lastname: Massias
authors.forename: Christodoulos I
authors.initials: CI
authors.lastname: Stefanadis
mesh_terms: D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000175:diagnosis*; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016277:Ventricular Function, Left