title: Segmental contribution to left ventricular systolic function at rest and stress: a quantitative real time three-dimensional echocardiographic study.
abstract: OBJECTIVE
  To assess the relative contribution of each myocardial segment to global systolic function during stress using real time three-dimensional echocardiography (RT3DE).
  
  
  BACKGROUND
  During stress, global augmentation in contractility results in an increased stroke volume. The relative contribution of each myocardial segment to these volumetric changes is unknown.
  
  
  METHODS
  Full volume was acquired using RT3DE at rest and following peak exercise in 22 patients who had no ischemia and no systolic dyssynchrony on two-dimensional (2D) stress echocardiography. The following were calculated at rest and peak stress: end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), relative SV, and relative EF.
  
  
  RESULTS
  With stress, an increase in global EDV from 90.8 to 101.1 ml (P < 0.001), SV from 59 to 78.4 ml (P = 0.01), and EF from 65.6 to 78.4% (P = 0.001) was observed. ESV decreased from 31.8 to 22.7 ml (P < 0.001). Segmental analysis revealed significantly higher SV, relative SV, and relative EF for the basal anterior, basal anterolateral, and basal inferolateral segments compared with the apical septum and apical inferior segments at both rest and stress (P < 0.001). The SV, relative SV, and relative EF increased significantly from apex to mid to base at both rest and stress (P < 0.001).
  
  
  CONCLUSIONS
  The relative volumetric contribution of each myocardial segment to global left ventricular systolic function at rest and stress is not uniform. The basal segments contribute more than the mid and apical segments. Specifically, the basal anterior, basal anterolateral, and basal inferolateral segments contribute the most to augmentation of left ventricular systolic function with exercise.
authors.affiliation: Department of Medicine Cardiovascular Medicine, Stony Brook University Medical Center, Stony Brook, New York 11794, USA. skort@notes.cc.sunysb.edu
authors.forename: Smadar
authors.initials: S
authors.lastname: Kort
authors.forename: Swapna
authors.initials: S
authors.lastname: Mamidipally
authors.forename: Purnema
authors.initials: P
authors.lastname: Madahar
authors.forename: Laura
authors.initials: L
authors.lastname: Buzzanca
authors.forename: Barbara
authors.initials: B
authors.lastname: Blizzard
authors.forename: Juan
authors.initials: J
authors.lastname: Gamboa
authors.forename: David L
authors.initials: DL
authors.lastname: Brown
mesh_terms: D000328:Adult; D000465:Algorithms; D003199:Computer Systems; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012146:Rest; D012680:Sensitivity and Specificity; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*