Mathematical model of a variable aperture mitral valve.

Previous models of pressure and flow waveforms during diastolic ventricular filling by the Waite et al. [2] described mitral valve behavior by a constant effective valve area and a constant valve impedance. A model to describe the opening process of the mitral valve was developed. The model is based on second-order dynamics and Bernoulli's equation. The earlier lumped variable model for diastolic filling was modified to reflect a variable mitral valve aperture. The combined model was calibrated using pressure and flow waveforms from porcine experiments and artificial transmitral pressure gradient waveforms. A comparison between the results of the combined model and the earlier fixed aperture model shows better agreement of experimental and simulated transmitral flow waveform in the combined model.