Fig. 4.
Sensitivity analysis of LV main diastolic properties. A: normalized Jacobian matrix of a control subject. Measured pressure is shown in the black dotted line. The impact of each diastolic index on instantaneous pressure is shown as the partial derivative of fitted pressure with respect to each index, normalized by its value. Elastic restoring forces are shown in green [constant of diastolic elastic recoil (S−) and LV minimum dead volume (Vd)], diastolic stiffness in blue [constant of diastolic passive stiffness (S+) and LV maximal achievable volume (Vm)], V0 in red, time constant of relaxation (τ) in yellow, and LV pressure at the onset of diastole (P0) in gray. Notice that early filling is governed by P0, τ, V0, and elastic restoring forces, whereas late filling is only influenced by V0 and diastolic stiffness. B: identical analysis as in A, in a patient with DCM. This ventricle does not contract below V0, so there is no contribution to filling of restoring forces. Additionally, notice that relaxation is not completed by end diastole, so end-diastolic pressure (EDP) is partially influenced by τ. C–F: resolution matrices of isovolumic relaxation (C and E) and full diastolic period (D and F). In this representation, the degree of autocorrelation among parameters is shown as the hue of gray, from no relationship (black) to full correlation (white).