Numerical evaluation of the slope and intercept of end-systolic pressure-volume relation

Numerical evaluation of two methods to calculate slope and intercept of endsystolic pressure-volume relation (ESPVR) in the left ventricle is presented. The mathematical formalism is based on results previously published in which the active force of the myocardium (also called isovolumic pressure Piso) is introduced in the formalism describing the pressure-volume relation (PVR) in the left ventricle. The numerical calculation is simple and can be easily implemented in routine clinical work, only the ventricular pressure Pm near endsystole needs to be estimated. A thick-walled cylindrical model contracting symmetrically is assumed for the left ventricle.