Velocity of contractile element shortening in constrictive pericarditis and the effect of pulsus paradoxus.
Force-velocity curves were constructed in nine patients with CP from a high-fidelity LV pressure tracing and its simultaneously recorded first derivative. Vmax and peak Vce (Vpm) were calculated using the 2-element (Hill) or Voigt model; the curves were also constructed and Vmax measured using the 3-element Maxwell model. The measurements were compared with those in a group of four patients with CMO and with two control subjects. Measurements of the celerity of ventricular contraction--peak LVdp/dt, Max d/IP and Vmax (2-element model)--were reduced in CP and greatly reduced in CMO. The effect of beat-to-beat variations in preload during pulsus paradoxus on the indices of ventricular celerity was studied. Peak LVdp/dt and Vpm varied with the change in LVEDP: the change in Vmax was negligible using the 2-element (Hill) or Voigt model. The 3-element (Maxwell) model failed to discriminate between the three groups of patients and seems to be invalid at high LV end-diastolic pressures.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002302:Cardiac Output; D002306:Cardiac Volume; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D007545:Isoproterenol; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D010494:Pericarditis, Constrictive / Q000503:physiopathology*; D005082:Physical Exertion; D011674:Pulse
D007545:Isoproterenol