Right ventricular mechanics: a comparison of models.

Using data from an isolated supported cat right ventricle preparation, we investigated the following models or methods for characterising the mechanical function of the ventricle: (1) a pressure generator in series with an internal impedance; (2) a variable elastance in series with an internal, pressure dependent flow resistance; (3) pulse response analyses, theoretically based on the pressure response to a small volume step of short duration; and (4) geometric mapping of the variables pressure and volume as functions of time. We tested the reproductive and predictive strengths of the four models, and found that all methods could reproduce 50% of the observed pressure curves with an RMS error less than 0.2 kPa, and in most cases also gave a close prediction of pressure curves which were not used to establish the respective model parameters. We see this as one reason for the fact that no single ventricular model has yet been universally accepted.