Interplay between Geometry, Fluid Dynamics, and Structure in the Ventricles of the Human Heart

Natural structures conveying fluid flow exhibit an interplay between flow-mediated forces and long-term adaptation. This phenomenon is relevant in the cardiovascular system where the geometric remod-eling of the heart chambers is the main mechanism underlying pathological progression leading to hearth failure. Cardiac adaptation is analyzed here in children with a single right ventricle (SRV) in their heart. In these patients, the left ventricle (LV) is not well developed and the healthy right ventricle (RV) is surgi-cally reconnected, early after birth, to take the functional role of the systemic ventricle. Such a condition represents a special model to investigate cardiac adaptation and this study takes advantage of the availabil-ity of an uncommon dataset (64 normal RVs, 64 normal LVs, 64 SRVs with clinically normal function). The ventricular functional performance is analyzed in terms of fluid dynamics and tissue deformation with the objective of verifying to which degree the SRV configuration adapts from the original RV and pro-gresses toward the function of a LV. Results show that the SRV immediately assumes a larger volume and a wider geometry due to the higher operating pressure. However, the fluid dynamics is weakly turbulent and produces a reduced propulsion. The surrounding tissue develops muscular thickening with multidi-rectional orientation of myofibers that mimic a LV. However, the reduced flow performance and a lower structural consistency makes the SRV at higher risk of progressive dysfunctional adaptations. This study demonstrates how the interplay between cardiac flow and tissue response represents the driving macro-scopic factor underlying the development of heart failure. More in general, the combined evaluation of fluid dynamics and structural functional properties can be a requirement for the exploration of adaptation processes across the different time scales.

Automated summary

This study analyzes the cardiac adaptation in children with a single right ventricle (SRV) in their heart and reveals that the SRV tries to adapt to fulfill the role of the systemic ventricle despite its developmental defect. The findings show that although the SRV increases in volume and geometry, its fluid dynamics is weak and its structural consistency is lower, making it more prone to progressive dysfunctional adaptations.