title: Poor correlation between left and right ventricular ejection fractions in patients with normal ventricular function.
abstract: OBJECTIVE
  Correlation between right and left ventricular ejection fraction (RVEF, LVEF) has been studied in only a small number of patients with a marked decrease in RVEF and LVEF. The goal of the present study was to compare LVEF and RVEF in a large population with low and normal ejection fractions (EFs) measured by blood pool scintigraphy.
  
  
  METHODS
  A series of 152 patients who underwent LVEF measurement for a clinical indication also underwent simultaneous measurement of the RVEF. The correlation between RVEF and LVEF in patients with or without depressed EF was studied using Pearson's regression analysis.
  
  
  RESULTS
  Although RVEF and LVEF were significantly correlated in an S curve mathematical function, the correlation was weak when the entire cohort was considered (r=0.32; P<0.001). However, when patients with lower EF (LVEF and RVEF less than 50%) were considered, the correlation was stronger (r=0.41; P<0.001), and in patients with normal biventricular EF (LVEF and RVEF 50% or greater), the correlation was completely absent (r=0.001; P=0.86). The strongest correlation between RVEF and LVEF occurred in patients with LVEF and RVEF less than 30% (r=0.75, P=0.03).
  
  
  CONCLUSIONS
  Patients with decreased EF have highest correlation between LVEF and RVEF in comparison with no correlation in patients with normal EF. The cause of this discrepancy is not known.
authors.affiliation: Department of Medicine, Section of Cardiology, University of Arizona Sarver Heart Center, Tucson, Arizona, USA.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Movahed
authors.forename: Norah
authors.initials: N
authors.lastname: Milne