Valveless pumping behavior of the simulated embryonic heart tube as a function of contractile patterns and myocardial stiffness

Author(s):  
Alireza Sharifi ◽  
Alex Gendernalik ◽  
Deborah Garrity ◽  
David Bark
Author(s):  
Jörg Männer ◽  
Talat Mesud Yelbuz

The early embryonic heart is a multi-layered tube consisting of (1) an outer myocardial tube; (2) an inner endocardial tube; and (3) an extracellular matrix layer interposed between myocardium and endocardium, called “cardiac jelly” (CJ). During the past decades, research on CJ has mainly focused on its molecular and cell biological aspects. This review focuses on the morphological and biomechanical aspects of CJ. Special attention is given to (1) the spatial distribution and fiber architecture of CJ; (2) the morphological dynamics of CJ during the cardiac cycle; and (3) the removal/remodeling of CJ during advanced heart looping stages, which leads to the formation of ventricular trabeculations and endocardial cushions. CJ acts as a hydraulic skeleton displaying striking structural and functional similarities with the mesoglea of jellyfish. CJ not only represents a filler substance, facilitating end-systolic occlusion of the embryonic heart lumen. Its elastic components antagonize the systolic deformations of the heart wall and thereby power the refilling phase of the ventricular tube. Non-uniform spatial distribution of CJ generates non-circular cross sections of the opened endocardial tube (initially elliptic, later deltoid), which seem to be advantageous for valveless pumping. Endocardial cushions arise from non-removed remnants of the original CJ.


ESC CardioMed ◽  
2018 ◽  
pp. 33-36
Author(s):  
Robert G. Kelly

The embryonic heart forms in anterior lateral splanchnic mesoderm and is derived from Mesp1-expressing progenitor cells. During embryonic folding, the earliest differentiating progenitor cells form the linear heart tube in the ventral midline. The heart tube extends in length and loops to the right as new myocardium is progressively added at the venous and arterial poles from multipotent second heart field cardiovascular progenitor cells in contiguous pharyngeal mesoderm. While the linear heart tube gives rise to the left ventricle, the right ventricle, outflow tract, and a large part of atrial myocardium are derived from the second heart field. Progressive myocardial differentiation is controlled by intercellular signals within the progenitor cell niche. The embryonic heart is the template for septation and growth of the four-chambered definitive heart and defects in progenitor cell deployment result in a spectrum of common forms of congenital heart defects.


Author(s):  
Ashok Ramasubramanian ◽  
Larry A. Taber

During cardiac c-looping, an important developmental phase in early heart development, the initially straight heart tube (HT) is transformed into a c-shaped tube. Two distinct processes, ventral bending and dextral rotation, constitute c-looping. Previous research suggests that ventral bending is likely driven by forces that are intrinsic to the heart while dextral rotation is driven by forces applied by a pair of omphalomesenteric veins that flank the heart tube and a membrane called the splanchnopleure that lies on top of the heart.


ESC CardioMed ◽  
2018 ◽  
pp. 33-36
Author(s):  
Robert G. Kelly

The embryonic heart forms in anterior lateral splanchnic mesoderm and is derived from Mesp1-expressing progenitor cells. During embryonic folding, the earliest differentiating progenitor cells form the linear heart tube in the ventral midline. The heart tube extends in length and loops to the right as new myocardium is progressively added at the venous and arterial poles from multipotent second heart field cardiovascular progenitor cells in contiguous pharyngeal mesoderm. While the linear heart tube gives rise to the left ventricle, the right ventricle, outflow tract, and a large part of atrial myocardium are derived from the second heart field. Progressive myocardial differentiation is controlled by intercellular signals within the progenitor cell niche. The embryonic heart is the template for septation and growth of the four-chambered definitive heart and defects in progenitor cell deployment result in a spectrum of common forms of congenital heart defects.


2006 ◽  
Vol 129 (3) ◽  
pp. 441-449 ◽  
Author(s):  
Larry A. Taber ◽  
Jinmei Zhang ◽  
Renato Perucchio

Early in development, the heart is a single muscle-wrapped tube without formed valves. Yet survival of the embryo depends on the ability of this tube to pump blood at steadily increasing rates and pressures. Developmental biologists historically have speculated that the heart tube pumps via a peristaltic mechanism, with a wave of contraction propagating from the inflow to the outflow end. Physiological measurements, however, have shown that the flow becomes pulsatile in character quite early in development, before the valves form. Here, we use a computational model for flow though the embryonic heart to explore the pumping mechanism. Results from the model show that endocardial cushions, which are valve primordia arising near the ends of the tube, induce a transition from peristaltic to pulsatile flow. Comparison of numerical results with published experimental data shows reasonably good agreement for various pressure and flow parameters. This study illustrates the interrelationship between form and function in the early embryonic heart.


2009 ◽  
Vol 126 ◽  
pp. S94
Author(s):  
Laurent Dupays ◽  
Surendra Kotecha ◽  
Timothy Mohun
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