Figure 5.

Impact of ventricular interdependence on elastic restoring forces. (A and B) Example of shape index (SI) analysis at the instant of minimum diastolic RV pressure (P_min) at baseline (A) and during late endotoxin infusion (B). Local 3-dimensional values of SI are shown for each vertex of the septum. A value of SI +1 accounts for a convex spherical geometry bending towards the RV, whereas a value of −1 accounts for a symmetric spherical concave geometry bending towards the LV. Changes in average SI values for the whole septum take place in parallel to changes in V₀. (C) Simultaneous RV and LV pressures during the same two phases showing the inversion in the trans-septal pressure difference from baseline to the late endotoxin phase. Arrowheads indicate the time of P_min. (D) The RV passive stiffness pressure curves obtained in the same animal following changes in V₀.