a malformed monozygotic twin fetus in which the heart is entirely absent.
A separate, grossly defective twin lacking a heart of its own, its blood supply being dependent on a shunt from the placental circulation of a more nearly normal twin; a placental parasitic twin or omphalosite. Compare: acardius.
[holo- + G. a- priv. + kardia, heart]
Etymology: Gk, holos + kardia, heart
a separate, grossly defective monozygotic twin fetus. It is usually a shapeless, nonformed mass in which the heart is absent and the circulation in utero is accomplished totally by the heart of the viable twin through a vascular shunt.
an unequal twin fetus in which the heart is entirely absent.