Integrated lumped parameter modeling of cardiac-vascular interaction with valve dynamics and ventricular...

Lumped-parameter cardiovascular models provide a useful framework for analyzing cardiac hemodynamics and valve-related flow disturbances. In this study, a lumped-parameter model was developed to investigate the hemodynamic response of the left ventricle and its interaction with aortic valve dynamics under physiological and pathological conditions.

The model incorporated time-varying ventricular elastance, valve flow relations, and vascular resistance-compliance effects to simulate pressure, flow, and volume variations over a cardiac cycle. The predicted waveforms were compared with a reference model to evaluate arrangement in magnitude, waveform shape, and phase synchronization. A systematic sensitivity analysis was also performed to assess the effects of arterial compliance (C_sat), minimum elastance (E_min), and stenosis severity (θ_max) on stroke volume (SV) and peak transvalvular pressure gradient (ΔP_peak).

The predicted pressure, flow, and volume waveforms showed good agreement with the reference model in terms of magnitude, waveform pattern, and timing. Arterial compliance had only a minor effect on both SV and ΔP_peak, mainly acting as a buffering parameter. Minimum elastance exerted a moderate influence on ventricular filling and pressure generation. In contrast, stenosis severity had the dominant effect on ΔP_peak, while its influence on SV was limited. This response reflected the nonlinear pressure-flow relationship across a restricted aortic valve.

The findings demonstrated that vascular compliance, myocardial elastance, and valve geometry contributed differently to cardiovascular dynamics. The model also showed that lumped-parameter approaches can be used to study ventricular-valvular interaction and may support diagnostic analysis and patient-specific cardiovascular assessment.