ESPVR, ejection fraction and heart failure.

The problem of heart failure with preserved ejection fraction (HFpEF) has recently received much attention. In this study we discuss some relations that connect ejection fraction EF to the parameters describing the end-systolic pressure-volume relation (ESPVR). It is shown that the study of the relation between EF and ESPVR can give some understanding of the problem of HFpEF. An important feature of the present approach is the introduction of the active force of the myocardium (also called isovolumic pressure) in the formalism describing the ESPVR.