title: Ventricular-arterial coupling assessment using gated single-photon emission computed tomography: relationship with reserve pulse pressure and repolarization abnormalities.
abstract: OBJECTIVE
  In patients with normal myocardial perfusion, ST-segment depression and reserve pulse pressure (rPP) can identify patients at higher risk of cardiovascular events. We aimed to explore the prevalence of impaired ventricular-arterial coupling (VAc) in patients with normal myocardial perfusion imaging and its relationship with ST-segment depression and rPP.
  
  
  RESULTS
  The present study included consecutive patients with normal myocardial perfusion imaging by single-photon emission computed tomography and ST-segment depression. Stroke volume, end-systolic pressure, arterial elastance (Ea), ventricular elastance (Ev), and VAc (Ea/Ev) were estimated both at rest and during stress. The difference between stress and rest (ΔVAc) was calculated. A positive ΔVAc was considered an impaired ΔVAc (iVAc).
  
  
  RESULTS
  A total of 92 patients were prospectively included. iVAc was identified in 44 (59%) patients with ST-segment depression compared with 3 (16%) patients with normal repolarization (P=0.001). A higher incidence of abnormal rPP was identified in patients with ST-segment depression compared with the control group (61 vs. 16%, P=0.0001). ST-segment depression was identified as the only independent predictor of iVAc (adjusted OR 7.5; 95% CI 1.9-30.0, P=0.004).
  
  
  CONCLUSIONS
  Noninvasive assessment of VAc is feasible with gated single-photon emission computed tomography and appears to be related to ST-segment depression and reserve rPP.
authors.affiliation: Department of Cardiovascular Imaging, TCBA, Buenos Aires, Argentina.
authors.forename: Osvaldo H
authors.initials: OH
authors.lastname: Masoli
authors.forename: Marcela
authors.initials: M
authors.lastname: Redruello
authors.forename: Lucas
authors.initials: L
authors.lastname: San Miguel
authors.forename: Jorgelina
authors.initials: J
authors.lastname: Medus
authors.forename: Nadia
authors.initials: N
authors.lastname: Pabstleben
authors.forename: Juan M
authors.initials: JM
authors.lastname: Blanco
authors.forename: Carlos
authors.initials: C
authors.lastname: Collaud
mesh_terms: D000368:Aged; D001794:Blood Pressure; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003326:Coronary Circulation; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011446:Prospective Studies; D012189:Retrospective Studies; D013318:Stroke Volume; D016276:Ventricular Function