title: Moderate intensity supine exercise causes decreased cardiac volumes and increased outer volume variations: a cardiovascular magnetic resonance study.
abstract: BACKGROUND
  The effects on left and right ventricular (LV, RV) volumes during physical exercise remains controversial. Furthermore, no previous study has investigated the effects of exercise on longitudinal contribution to stroke volume (SV) and the outer volume variation of the heart. The aim of this study was to determine if LV, RV and total heart volumes (THV) as well as cardiac pumping mechanisms change during physical exercise compared to rest using cardiovascular magnetic resonance (CMR).
  
  
  METHODS
  26 healthy volunteers (6 women) underwent CMR at rest and exercise. Exercise was performed using a custom built ergometer for one-legged exercise in the supine position during breath hold imaging. Cardiac volumes and atrio-ventricular plane displacement were determined. Heart rate (HR) was obtained from ECG.
  
  
  RESULTS
  HR increased during exercise from 60±2 to 94±2 bpm, (p<0.001). LVEDV remained unchanged (p=0.81) and LVESV decreased with -9±18% (p<0.05) causing LVSV to increase with 8±3% (p<0.05). RVEDV and RVESV decreased by -7±10% and -24±14% respectively, (p<0.001) and RVSV increased 5±17% during exercise although not statistically significant (p=0.18). Longitudinal contribution to RVSV decreased during exercise by -6±15% (p<0.05) but was unchanged for LVSV (p=0.74). THV decreased during exercise by -4±1%, (p<0.01) and total heart volume variation (THVV) increased during exercise from 5.9±0.5% to 9.7±0.6% (p<0.001).
  
  
  CONCLUSIONS
  Cardiac volumes and function are significantly altered during supine physical exercise. THV becomes significantly smaller due to decreases in RVEDV whilst LVEDV remains unchanged. THVV and consequently radial pumping increases during exercise which may improve diastolic suction during the rapid filling phase.
authors.forename: Katarina
authors.initials: K
authors.lastname: Steding-Ehrenborg
authors.forename: Robert
authors.initials: R
authors.lastname: Jablonowski
authors.forename: Per M
authors.initials: PM
authors.lastname: Arvidsson
authors.forename: Marcus
authors.initials: M
authors.lastname: Carlsson
authors.forename: Bengt
authors.initials: B
authors.lastname: Saltin
authors.affiliation: Department of Clinical Physiology, Lund University, Lund University Hospital Lund, Lund, Sweden. hakan.arheden@med.lu.se.
authors.forename: Håkan
authors.initials: H
authors.lastname: Arheden
mesh_terms: D000328:Adult; D004562:Electrocardiography; D015444:Exercise; D005260:Female; D064368:Healthy Volunteers; D006339:Heart Rate; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013318:Stroke Volume; D016683:Supine Position; D013997:Time Factors; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D055815:Young Adult