| Namespace | MPheno.ontology | Obsolete | false |
| description | a heart with 3 atria, is in which either the left or right atrium is divided into 2 parts by a fold of tissue, a membrane, or a fibromuscular band that may vary significantly in size and shape, appearing similar to a diaphragm or funnel-shaped, bandlike, entirely intact (imperforate) or contain 1 or more openings (fenestrations) ranging from small, restrictive-type to large and widely open |
