| Namespace | MPheno.ontology | Obsolete | false |
| description | any structural anomaly of the paired, longitudinal, endothelial-lined channels formed from the cardiogenic mesoderm in embryonic development; angiogenic cell clusters (aka angioblastic cords) located in a horse-shoe shape configuration in the cardiogenic plate coalesce to form the right and left endocardial heart tubes which then fuse in cephalo-caudal direction to form a single primitive heart tube |