title: The association between right ventricular free wall strain and exercise capacity for health check-up subjects.
abstract: BACKGROUND
  Right ventricular (RV) function has been found to be a major factor of exercise capacity in patients with heart failure. However, the role of RV function in exercise capacity in healthy subjects has not been well studied. This study aims to validate the role of RV strain derived from speckle tracking echocardiography for exercise capacity for health check-up subjects.
  
  
  METHODS
  This study prospectively recruited subjects from a routine health examination. All of them were symptom free. RV function represented by RV strain was derived from speckle tracking echocardiography in addition to traditional echocardiography parameters. Functional capacity was determined by a symptom limited treadmill exercise test with the Bruce protocol.
  
  
  RESULTS
  Among 164 recruited subjects (age 52.2 ±9.2 years, 66.4% male), 32 subjects represented impaired functional capacity (MET<8), which was significantly correlated with age, left ventricular mass index, left ventricular filling pressure (E/e'), global longitudinal strain of the left ventricle (LVGLS) (-16.0±2.5% vs. -18.9±3.8%, p < 0.001) and RV free wall strain (RVLS_FW) (-17.0±4.9% vs. -21.9±3.2%, p <0.001). After multivariate logistic regression, RVS_FW was an independent predictor for impaired functional capacity (OR 1.62, CI 1.32-1.98; p <0.001).
  
  
  CONCLUSIONS
  In conclusion, RV strain is independently associated with exercise capacity for health check-up subjects. RV function is an important factor for functional capacity.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chi-Mei Medical Center, Yungkang Dist, Tainan, Taiwan.|Division of Cardiology, National Cheng Kung University Hospital, Tainan, Taiwan.|Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Chang
authors.affiliation: Division of Cardiology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Yen-Wen
authors.initials: YW
authors.lastname: Liu
authors.affiliation: Division of Cardiology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Ping-Yen
authors.initials: PY
authors.lastname: Liu
authors.affiliation: Department of Internal Medicine, Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Chih-Hsin
authors.initials: CH
authors.lastname: Hsu
authors.affiliation: Division of Cardiology, National Cheng Kung University Hospital, Tainan, Taiwan.
authors.forename: Wei-Chuan
authors.initials: WC
authors.lastname: Tsai
mesh_terms: D000328:Adult; D004562:Electrocardiography; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010808:Physical Examination; D015203:Reproducibility of Results; D013624:Taiwan; D016278:Ventricular Function, Right