Graphical estimation of ventricular wall force and stress from pressure-volume diagram.

A graphical method is proposed for assessment of ventricular wall circumferential total force and mean stress from the ventricular pressure-volume diagram. A family of force or stress isopleths are first drawn in the pressure-volume plane using a geometric model of the left ventricle and an appropriate version of the Laplace equation. A pressure-volume loop of the ventricle to be analyzed is then drawn in this pressure-volume plane. Total circumferential force in the ventricular wall or its mean circumferential stress can now be read directly from the intersections of the pressure-volume loop with the force or stress isopleths.