ABSTRACT
The active force developed by the muscular fibres of the myocardium is represented
as force per unit volume of the myocardium and included in the formalism describing
the pressure-volume relation (PVR) and the end-systolic pressure-volume relation
(ESPVR) in the left or right ventricle. Experimental methods to measure or to
calculate the parameters describing PVR have often given inconsistent results. The
objective of this study is to introduce some new mathematical relations describing the
properties of PVR. Verifications based on published experimental data are given.
Suggestions for future experimental work are indicated. The lack of adequate
mathematical formalism to verify the consistency of experimental data is the main
reason that prevents the application of PVR and ESPVR in routine clinical work.