title: Exercise-induced ST elevation in patients with non-ischemic dilated cardiomyopathy and narrow QRS complexes: novel predictor of long-term prognosis from exercise testing.
abstract: BACKGROUND
  The clinical significance and prevalence of exercise-induced ST elevation (ESTE) in non-ischemic dilated cardiomyopathy (NIDCM) patients are unknown.
  
  
  RESULTS
  We retrospectively examined 12-lead ECGs during cardiopulmonary exercise testing in 360 consecutive NIDCM patients (left ventricular ejection fraction (LVEF) <45%) with narrow QRS. ESTE was defined as ≥1.0mm ST (J-point) elevation compared with baseline. During long-term follow-up for major cardiac events (death, transplantation, or LV assist device implantation), ESTE was recognized in 50 patients (14%). They had much lower LVEF than patients without ESTE (20±7% vs. 27±7%, respectively, P<0.001), whereas the differences in peak VO2 (P=0.01) and VE/VCO2 slope (P=0.04) were relatively small. Major cardiac events occurred more frequently in patients with ESTE than in those without ESTE (39% vs. 12% at 48 months). Increased event rates were associated with low peak VO2 (<14ml·min(-1)·kg(-1)) in patients without ESTE (39% vs. 23%, P<0.05), but not in those with ESTE (50% vs. 62%, NS). Cox multivariate analysis revealed ESTE as the strongest independent prognosticator among exercise parameters (hazard ratio: 2.41 [95% confidence interval 1.03-5.63], P<0.05).
  
  
  CONCLUSIONS
  A substantial number of NIDCM patients exhibit ESTE, which indicates a poor prognosis. Low peak VO2 and ESTE may reflect different aspects of the pathophysiological processes that deteriorate heart failure.
authors.affiliation: Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Takaki
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sata
authors.forename: Kazushi
authors.initials: K
authors.lastname: Sakane
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ino
authors.forename: Teruo
authors.initials: T
authors.lastname: Noguchi
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Goto
authors.forename: Masaru
authors.initials: M
authors.lastname: Sugimachi
mesh_terms: D000328:Adult; D002311:Cardiomyopathy, Dilated / Q000401:mortality* / Q000503:physiopathology*; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D006353:Heart-Assist Devices; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013318:Stroke Volume