A pictorial account of the human embryonic heart between 3.5 and 8 weeks of development

Jill P J M Hikspoors,Robert H Anderson,Greet M C Mommen,Nutmethee Kruepunga,Wouter H Lamers,S Eleonore Köhler

doi:10.1038/s42003-022-03153-x

Jill P J M Hikspoors, Robert H Anderson + Show 4 more

Open Access

https://doi.org/10.1038/s42003-022-03153-x

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Abstract

Heart development is topographically complex and requires visualization to understand its progression. No comprehensive 3-dimensional primer of human cardiac development is currently available. We prepared detailed reconstructions of 12 hearts between 3.5 and 8 weeks post fertilization, using Amira® 3D-reconstruction and Cinema4D®-remodeling software. The models were visualized as calibrated interactive 3D-PDFs. We describe the developmental appearance and subsequent remodeling of 70 different structures incrementally, using sequential segmental analysis. Pictorial timelines of structures highlight age-dependent events, while graphs visualize growth and spiraling of the wall of the heart tube. The basic cardiac layout is established between 3.5 and 4.5 weeks. Septation at the venous pole is completed at 6 weeks. Between 5.5 and 6.5 weeks, as the outflow tract becomes incorporated in the ventricles, the spiraling course of its subaortic and subpulmonary channels is transferred to the intrapericardial arterial trunks. The remodeling of the interventricular foramen is complete at 7 weeks.

Highlights

The description of human cardiac development based on magnetic resonance or fluorescent episcopic microscopy is instructive[12]
In the Blechschmidt collection, we found two CS15 embryos who had not yet formed a secondary foramen and two others who had, like the reconstructed specimen, both primary and secondary foramens
The aortopulmonary septum, initially seen at CS14 as a transverse protrusion extending from the dorsal wall of the aortic sac between the origins of the arteries of the 4th and 6th pair of pharyngeal arches, extends obliquely in a ventral direction toward the distal margins of the endocardial ridges in the middle portion of the outflow tract

Summary

Introduction

Heart development is topographically complex and requires visualization to understand its progression. At CS10, the cranial second heart field gives rise to the embryonic right ventricle proximally[42], while the distal portion becomes the myocardial outflow tract at CS11

Results

Conclusion