Isomerism
Isomerism is a term which in general means 'mirror-image' and refers to finding normally-asymmetric bilateral structures to be similar. It is used in the context of heterotaxy and is of two types:
- left isomerism
- right isomerism
Left isomerism
Mirror image of the structures on the left side of the chest along the left-right axis of the body, i.e. patients with isomeric left atrial appendages frequently have bilobed lungs bilaterally and each with a long bronchus . Additionally, they have polysplenia and pulmonary veins connecting to both atrial chambers.
Right isomerism
Mirror image of the structures on the right side of the chest along the left-right axis of the body, i.e. patients with isomeric right atrial appendages frequently have trilobed lungs bilaterally and each with a short bronchus . Additionally characterized by asplenia.
100% symmetry does not occur.
History and etymology
The term isomerism is derived from Greek: "iso" meaning equal and "meros" meaning part.
See also
