title: Differences in myocardial velocities during supine and upright exercise stress echocardiography in healthy adults.
abstract: BACKGROUND
  Tissue Velocity Imaging (TVI) is a method for quantitative analysis of longitudinal myocardial velocities, which can be used during exercise and pharmacological stress echocardiography. It is of interest to evaluate cardiac response to different types of stress tests and the differences between upright and supine bicycle exercise tests have not been fully investigated. Therefore, the aim of this study was to compare cardiac response during supine and upright exercise stress tests.
  
  
  METHODS
  Twenty young healthy individuals underwent supine and upright stress test. The initial workload was set to 30 W and was increased every minute by a further 30 W until physical exhaustion. Tissue Doppler data from the left ventricle were acquired at the end of every workload level using a GE Vivid7 Dimension system (>200 frames s(-1)). In the off-line processing, isovolumic contraction velocity (IVCV), peak systolic velocity (PSV), isovolumic relaxation velocity (IVRV), peak early diastolic velocity (E') and peak late diastolic velocity (A') were identified at every workload level.
  
  
  RESULTS
  No significant difference between the tests was found in PSV. On the contrary, E' was shown to be significantly higher (P<0.001) during supine exercise than during upright exercise and IVRV was significantly lower (P<0.001) during supine exercise compared to upright exercise.
  
  
  CONCLUSIONS
  Upright and supine exercise stress echocardiography give a comparable increase in measured systolic velocities and significant differences in early diastolic velocities.
authors.affiliation: School of Technology and Health, Royal Institute of Technology (KTH) Huddinge, Stockholm, Sweden. anna.bjallmark@sth.kth.se
authors.forename: Anna
authors.initials: A
authors.lastname: Bjällmark
authors.forename: Matilda
authors.initials: M
authors.lastname: Larsson
authors.forename: Kambiz
authors.initials: K
authors.lastname: Shahgaldi
authors.forename: Britta
authors.initials: B
authors.lastname: Lind
authors.forename: Reidar
authors.initials: R
authors.lastname: Winter
authors.forename: Lars-Ake
authors.initials: LA
authors.lastname: Brodin
mesh_terms: D000328:Adult; D001642:Bicycling; D018618:Echocardiography, Doppler, Color; D025401:Echocardiography, Stress; D005080:Exercise Test; D005240:Feasibility Studies; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D009200:Myocardial Contraction; D010807:Physical Endurance; D011187:Posture; D016683:Supine Position; D013997:Time Factors; D055815:Young Adult