Physical parameters representing the energy components of the cardiac
pump related to inertance, resistance, and compliance are developed. The
martingale optimality principle and the Malliavin calculus are used to
estimate these time-varying parameters. The methods are applied to the
ejection phase of the cardiac cycle, using pressure and flow measured at
the root of the aorta for the left ventricle. We find the compliance
parameter to be in general agreement with data reported by others, but
our resistive parameter differs considerably and has a value
commensurate with the expected efficiency of the cardiac pump. The
inertance parameter, not represented in models reported by others, is
shown to be of significance and may contribute to differences in values
of the other parameters.