Age-Dependence of Flow Homeostasis in the Left Ventricle

Conclusions: In average, blood spends 1 to 3 beats inside the LV with very low shear stress rates. The apical region is the most prone to blood stasis, particularly in mid-aged adults. The washout of blood in the normal LV is age-dependent due to physiological changes in the degree of apical penetration of the filling waves. Introduction Cardioembolic stroke is a major source of mortality and disability worldwide and blood stasis one of its major determinants (Adams et al., 1986). Left ventricular (LV) function has evolved to maximize mechanical efficiency and ensure organ perfusion at a low cost of energy and filling pressures. An additional requirement of blood flow homeostasis is avoiding the risk of thrombosis inside cardiac chambers. Blood flow arrangement inside the LV ensures an effective washout and protects blood elements against high shear stresses (Kilner et al., 2000; Lowe, 2003). However, blood does not transit the LV following a first-in-first-out rule; even in normal hearts, a significant fraction of the blood entering the LV is not ejected during the ensuing systole (Bolger et al., 2007; Eriksson et al., 2011). This fraction increases in diseased hearts, potentially resulting in blood stagnation and eventually thrombosis inside the chamber (Eriksson et al., 2011; Hendabadi et al., 2013; Rossini et al., 2017). Thus, understanding the physiological foundations of intraventricular blood transit is of major clinical relevance. Furthermore, although avoidi...
Source: Frontiers in Physiology - Category: Physiology Source Type: research