COMPARISON OF DIASTOLIC FILLING MODELS AND THEIR FIT TO TRANSMITRAL DOPPLER CONTOURS

Anatomic/physiologic and kinematic mathematical models of diastolic fi lling which employ (lumped) parameters of diastolic function have been used to predict or characterize transmitral flow. The ability to dete rmine model parameters from clinical transmitral flow, the Doppler vel ocity profile (DVP), is equivalent to solving the ''inverse problem'' of diastole, Systematic model-to-model and model-to-data comparison ha s never been carried out, in part due to the requirement that DVPs be digitized by hand, We developed, tested and verified a computerized me thod of DVP acquisition and reproduction, and carried out numerical de termination of model-to-model and model-to-data goodness-of-fit, The t ransmitral pow velocity of two anatomic/physiologic models and one kin ematic model were compared, Each model's ability to fit computer-acqui red and reproduced transmitral DVPs was assessed, Results indicate tha t transmitral flow velocities generated by the three models are graphi cally indistinguishable and are able to fit the E-wave of clinical DVP s with comparable mean-square errors, Nonunique invertibility of the a natomic/physiologic models was verified, i.e., multiple sets of model parameters could be found that fit a single DVP with comparable mean-s quare error, The kinematic formulation permitted automated, unique, mo del-parameter determination, solving the ''inverse problem'' for the D oppler E-wave, We conclude that automated, quantitative characterizati on of clinical Doppler E-wave contours using this method is feasible, The relation of kinematic parameters to physiologic variables is a sub ject of current investigation.