The mini-heart: a step toward non-invasive cardiac pump models.

“First, the mini-heart did not generate the pressure–volume loop characteristic of physiological pumping function; instead, the loop appeared non-linear and double-helical, which the authors attribute to the absence of valves and to dynamic pressure imposed by fluid inertia at the inlet column. Incorporating valve-like elements—an approach proposed but not yet implemented in comparable chamber models—may help address this limitation. Establishing a more comprehensive pressure model, informed by direct comparison with invasive measurement techniques, would also strengthen confidence in the non-invasive readout.”

“In this issue of Cardiovascular Research, Ribeiro et al. describe a simplified ‘mini-heart’, generated from hPSC-CMs and cardiac fibroblasts (CFs), that exhibits the haemodynamic function and electrophysiology of a cardiac ventricular chamber. Using sacrificial moulding, the authors cast hPSC-CMs and CFs into a miniature ventricle coupled to a glass capillary, enabling haemodynamic measurement of contractile function. Through optical imaging, the authors demonstrate drug-induced physiological responses in this mini-heart, suggesting a promising step forward from conventional EHTs.”