Hematologic disorders and congenital cardiovascular malformations: converging lines of research.

In a population-based study on congenital cardiovascular malformations (CCVM), the occurrence of heritable coagulopathies among case parents and not among controls raised the possibility of an etiologic association of CCVM with blood disorders. The literature was searched for evidence that such an association could be biologically plausible. Reported embryologic and clinical data provided confirmatory findings. The heart and blood arise from common angiogenic cells; endothelial cells, the first components of the primitive heart, synthesize coagulation factors; resultant osmotic alterations of embryonic fluids could alter early cardiac morphogenesis. Bleeding diatheses are common in cyanotic and acyanotic patients with CCVM and hemostatic disorders have been reported in some families. CCVM and blood disorders are joint components of several malformation syndromes. The hypothesis of an etiologic relationship between HBD and CCVM needs to be tested in multiple research areas. Future experimental studies should be based on current theories of cardiac morphogenesis to include investigations of embryonic blood in genetic blood disorders. Clinical studies should clarify hematologic alterations in CCVM probands and their families.