title: Does left atrial volume affect exercise capacity of heart transplant recipients?
abstract: BACKGROUND
  Heart transplant (HT) recipients demonstrate limited exercise capacity compared to normal patients, very likely for multiple reasons. In this study we hypothesized that left atrial volume (LAV), which is known to predict exercise capacity in patients with various cardiac pathologies including heart failure and hypertrophic cardiomyopathy is associated with limited exercise capacity of HT recipients.
  
  
  METHODS
  We analyzed 50 patients [age 57 ±2 (SEM), 12 females] who had a post-HT echocardiography and cardiopulmonary exercise test (CPX) within 9 weeks time at clinic follow up. The change in LAV (ΔLAV) was also computed as the difference in LAV from the preceding one-year to the study echocardiogram. Correlations among the measured parameters were assessed with a Pearson's correlation analysis.
  
  
  RESULTS
  LAV (n = 50) and ΔLAV (n = 40) indexed to body surface area were 40.6 ± 11.5 ml·m-2 and 1.9 ± 8.5 ml·m-2·year-1, data are mean ± SD, respectively. Indexed LAV and ΔLAV were both significantly correlated with the ventilatory efficiency, assessed by the VE/VCO2 slope (r = 0.300, p = 0.038; r = 0.484, p = 0.002, respectively). LAV showed a significant correlation with peak oxygen consumption (r = -0.328, p = 0.020).
  
  
  CONCLUSIONS
  Although our study is limited by a retrospective study design and relatively small number of patients, our findings suggest that enlarged LAV and increasing change in LAV is associated with the diminished exercise capacity in HT recipients and warrants further investigation to better elucidate this relationship.
authors.affiliation: Division of Cardiovascular Diseases, Department of Internal Medicine University of Cincinnati, Cincinnati, Ohio, USA. shizukya@uc.edu.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Abdul-Waheed
authors.forename: Mian
authors.initials: M
authors.lastname: Yousuf
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Kelly
authors.forename: Ross
authors.initials: R
authors.lastname: Arena
authors.forename: Jun
authors.initials: J
authors.lastname: Ying
authors.forename: Tehmina
authors.initials: T
authors.lastname: Naz
authors.forename: Stephanie H
authors.initials: SH
authors.lastname: Dunlap
authors.forename: Yukitaka
authors.initials: Y
authors.lastname: Shizukuda
mesh_terms: D004452:Echocardiography; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D016027:Heart Transplantation / Q000000981:diagnostic imaging* / Q000473:pathology / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012123:Pulmonary Ventilation