Asymmetric redirection of flow through the heart

Abstract

Through cardiac looping during embryonic development, paths of flow through the mature heart have direction changes and asymmetries whose topology and functional significance remain relatively unexplored. Here we show, using magnetic resonance velocity mapping, the asymmetric redirection of streaming blood in atrial and ventricular cavities of the adult human heart, with sinuous, chirally asymmetric paths of flow through the whole. On the basis of mapped flow fields and drawings that illustrate spatial relations between flow paths, we propose that asymmetries and curvatures of the looped heart have potential fluidic and dynamic advantages. Patterns of atrial filling seem to be asymmetric in a manner that allows the momentum of inflowing streams to be redirected towards atrio-ventricular valves, and the change in direction at ventricular level is such that recoil away from ejected blood is in a direction that can enhance rather than inhibit ventriculo-atrial coupling. Chiral asymmetry might help to minimize dissipative interaction between entering, recirculating and outflowing streams. These factors might combine to allow a reciprocating, sling-like, 'morphodynamic' mode of action to come into effect when heart rate and output increase during exercise.

Left Ventricular Fluid Mechanics: The Long Way from Theoretical Models to Clinical Applications

“…It showed the well-defined vortex ring-like structure of the vorticity field, (see Fig. 1 for an exemplary case), in qualitative agreement with a previous in vivo study 51 and a following mixed numerical and experimental one. 22 A further study analyzed the influence of the eccentric position of mitral orifice with respect to the LV geometry, 73 suggesting that the physiological arrangement corresponds to the minimal kinetic energy dissipation within the LV.…”

Comparative numerical study on left ventricular fluid dynamics after dilated cardiomyopathy

“…The phenomenological organization of the LV flow in the normal subjects is in agreement with those reported in the literature. It has been confirmed that normal diastolic filling is characterized by the presence of a 3D vorticity structure that develops into a dominant asymmetric vortex, a relatively smooth wheel-like motion over the whole cavity, which is associated with flow redirection toward the aorta (Kilner et al, 2000;Pedrizzetti and Domenichini, 2005). This global picture significantly changes in the context of DCM.…”

Accuracy of four-dimensional phase-contrast velocity mapping for blood flow visualizations: a phantom study

“…Phase-contrast velocity mapping with magnetic resonance imaging (PC-MRI) has become an important tool for quantifying and visualizing blood flow patterns in the human body (1)(2)(3)(4).…”