Key result
Left atrial pressure estimation from total artificial heart parameters is largely independent of venous compliance, but uncertainty is high at high end diastolic volume and short diastole duration.
Why the study?
Physiological control of a total artificial heart requires reliable left atrial pressure information, but the transfer function and uncertainties when deriving it indirectly from intrinsic parameters need to be understood.
Can left atrial pressure be reliably estimated from intrinsic parameters (EDV and Td) in a total artificial heart across different venous compliances?
Can left atrial pressure be reliably estimated from intrinsic parameters (EDV and Td) in a total artificial heart across different venous compliances?
Physiological regulation of a total artificial heart using estimated LAP does not require individual adaptation to patient venous compliance, but must account for uncertainties at high EDV and short diastole duration.
Supports TAH LAP estimation without venous compliance adjustment in animals; leaves open reliability at high EDV/short diastole for clinical translation.
A physiological control of a total artificial heart (TAH) requires reliable information on left arterial pressure (LAP). When LAP is derived indirectly from intrinsic TAH parameters like end diastolic volume (EDV) and diastole duration (Td), the transfer function and associated uncertainties need to be well understood.We derived a computational equivalent to a hydraulic model consisting of the venous compliance, the heart valve and the pump chamber, and studied the filling phase in cases of different venous compliance. We calculated a family of curves of pump chamber volume as a function of time for different venous compliances and LAP. To visualize the LAP transfer function and uncertainties associated to EDV, Td measurement error and unknown venous compliance a family of similar curves in the vicinity of assumed measurement was found and visualised in the parameter space.Results were in a realistic absolute range and showed expected trends despite some simplifications in the simulation model. The venous compliance has no significant influence on LAP values extracted from EDV and Td, except at very low values. The uncertainty in the extracted LAP is particularly high for high EDV and short Td.A physiological regulation therefore does not have to be individually adapted to the patient's venous compliances, but has to deal with uncertainties in the input values like blood pressures extracted from intrinsic device parameters.
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Diedrich et al. (2019) studied Total artificial heart. Left atrial pressure estimation from intrinsic TAH parameters was evaluated on Reliability and uncertainty of LAP transfer function. Left atrial pressure estimation from total artificial heart parameters is largely independent of venous compliance, but uncertainty is high at high end diastolic volume and short diastole duration.
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