The influence of Hill's force-velocity relation on left ventricular mechanics in simulated hypertensive conditions with variable afterload.

Hill's force-velocity relationship is integrated into a 3D left-ventricular finite element model to enhance myocardial contraction dynamics alongside the Frank-Starling mechanism. Hypertensive conditions were simulated by adjusting arterial resistance and compliance to mimic varying afterload, with damping applied on velocity as an alternative stabilization method for numerical stability. Hill's relationship reduced peak systolic pressures (6.3%-7.2%) as hypertension progressed, moderated shortening velocities (1.61-1.69 s^-1), and prevented velocity overshoot. Cardiac output was preserved, and ejection fraction remained unaffected. These findings highlight Hill's role in regulating systolic function, optimizing myocardial response under elevated afterload, and improving predictive capabilities for hypertensive heart disease.