title: Left ventricular wall stress during leg-press exercise performed with a brief Valsalva maneuver.
abstract: OBJECTIVE
  To assess the effects of leg-press (LP) exercise performed with a brief (2 to 3 s) Valsalva maneuver on left ventricular (LV) systolic function and LV wall stress in five healthy men (mean +/- SD age, 27.6 +/- 2.9 years).
  
  
  METHODS
  Subjects performed submaximal (80% one repetition maximum [1RM], 337.9 +/- 109.1 kg; 95% 1RM, 400.6 +/- 129.8 kg) and maximal LP exercise (420 +/- 118.6 kg) during which central arterial pressure, intrathoracic pressure, and two-dimensional echocardiographic analysis of LV systolic function and LV wall stress were measured.
  
  
  RESULTS
  Compared with baseline, LP exercise resulted in an increase in intrathoracic pressure (baseline, 1.7 +/- 2.9 mm Hg; 80% 1RM, 111.7 +/- 20.2 mm Hg; 95% 1RM, 112.2 +/- 21.1 mm Hg; 100% 1RM, 111.0 +/- 21.3 mm Hg; p < 0.05) and LV end-systolic pressure (baseline, 120.0 +/- 13.2 mm Hg; 80% 1RM, 251.6 +/- 15.3 mm Hg; 95% 1RM, 255.3 +/- 12.2 mm Hg; 100% 1RM, 242.8 +/- 16.5 mm Hg; p < 0.05) with no changes in LV end-systolic transmural pressure (baseline, 118.3 +/- 12.6 mm Hg; 80% 1RM, 140.0 +/- 6.1 mm Hg; 95% 1RM, 143.1 +/- 16.1 mm Hg; 100% 1RM, 131.8 +/- 29.7 mm Hg; p > 0.05), LV end-systolic wall stress (baseline, 91.7 +/- 20.2 kilodyne/cm(2); 80% 1RM, 78.0 +/- 24.4 kilodyne/cm(2); 95% 1RM, 81.4 +/- 25.3 kilodyne/cm(2); 100% 1RM, 85.9 +/- 20.1 kilodyne/cm(2); p > 0.05), or LV fractional area change (baseline, 0.48 +/- 0.03; 80% 1RM, 0.52 +/- 0.11; 95% 1RM, 0.53 +/- 0.06; 100% 1RM, 0.52 +/- 0.05; p > 0.05).
  
  
  CONCLUSIONS
  LP exercise performed with a brief Valsalva maneuver is not associated with an alteration in LV wall stress or LV systolic function in healthy young men.
authors.affiliation: Faculty of Physical Education and Recreation, and Division of Cardiology, University of Alberta, Edmonton, Alberta, Canada. mark.haykowsky@ualberta.ca
authors.forename: M
authors.initials: M
authors.lastname: Haykowsky
authors.forename: D
authors.initials: D
authors.lastname: Taylor
authors.forename: K
authors.initials: K
authors.lastname: Teo
authors.forename: A
authors.initials: A
authors.lastname: Quinney
authors.forename: D
authors.initials: D
authors.lastname: Humen
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D004452:Echocardiography; D005080:Exercise Test; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D012016:Reference Values; D013599:Systole / Q000502:physiology*; D014636:Valsalva Maneuver / Q000502:physiology*; D016277:Ventricular Function, Left / Q000502:physiology*