Modeling Partial and Total Support of Left Ventricular Assist Device for Discrete Hemodynamic Control Framework.

OBJECTIVES

This study develops a model-based control framework integrating a left ventricular assist device (LVAD) with drug therapy to regulate multidimensional hemodynamics (mean arterial pressure, cardiac output, and left and right atrial pressures) while minimizing myocardial oxygen consumption ($MVO_{2}$) in acute heart afailure (AHF). By modeling the hemodynamic and $MVO_{2}$ effects of partial and total LVAD support, the framework enables combined drugs-LVAD therapy for severe AHF cases where drug therapy alone is not effective.

METHODS

A previously developed hemodynamic control framework was extended to incorporate LVAD support. Using circulatory equilibrium models under LVAD support, an analytical $MVO_{2}$ model encompassing both LVAD modes was derived from the relationship between $MVO_{2}$ and the ventricular pressure-volume area. An optimal controller explicitly accounts for transitions between partial and total LVAD support. In our cardiovascular simulator, we validated the $MVO_{2}$ model and evaluated the framework's multidimensional hemodynamic regulation and $MVO_{2}$ minimization capabilities.

RESULTS

The $MVO_{2}$ model accurately predicted $MVO_{2}$ across the two LVAD modes. In a severe AHF scenario, drug therapy or LVAD support alone failed, whereas the combined drugs-LVAD controller succeeded in achieving both hemodynamic regulation and $MVO_{2}$ minimization. Compared with drug therapy alone, drugs-LVAD control using the proposed $MVO_{2}$ model halved $MVO_{2}$ while achieving multidimensional regulation.

CONCLUSIONS

Our drugs-LVAD framework may enable multidimensional hemodynamic regulation while reducing $MVO_{2}$ in severe AHF. Modeling both partial and total LVAD support may be essential for hemodynamic management.

SIGNIFICANCE: This work provides a theoretical basis for integrated drugs-LVAD control to achieve target hemodynamics while reducing cardiac workload.