Figure 7. Comparison between computed and experimental systolic wall stress.

Values of left ventricular end-systolic stress experienced by cardiomyocytes within the human heart were calculated by modeling the ventricle as a prolate spheroid-shaped pressure vessel. (A) Loads produced by our magnetic afterload device were calculated, assuming a circular tissue cross-section and that 20% of the EHT cross-sectional area was occupied by cardiomyocytes. Where, k is the post stiffness, d is the tissue diameter, σ is the calculated tissue stress, and σ_c is the cardiomyocyte-perceived stress. (B) Published values of left ventricular diameters, wall thickness, and pressure at end systole were used to estimate stress from 16 to 40 weeks of gestation. (C) A previously established equation was used to calculate stress from birth onwards²⁸. (C) The blue regions in the graphs indicate the range of stresses applied by the afterload device, where the upper and lower bounds are indicated by dashed lines.