Embryology of coronary arteries and anatomy/pathophysiology of coronary anomalies. A comprehensive update.

OBJECTIVES: This paper reviews new findings in both embryology of coronary arteries and in clinical observations of coronary artery anomalies. FOCUS: Our presentation emphasizes studies based on: 1) newer methods of coronary development in animals and humans, and 2) intravascular ultrasonography to interpret pathophysiology and guide treatment of coronary anomalies.
CONCLUSIONS: New data reveal the roles of many cellular interactions and signaling pathways involved in the normal and abnormal formation of the coronary arterial system and the consequences of their defective formation. Pathogenetic developmental mechanisms include dysfunction of the Notch and Hypo signaling pathways, angiogenic and arteriogenic molecules, and neural crest cells. We addressed numerous clinically significant coronary anomalies and their prevalence in a general population (especially those characterized by an ectopic origin with aortic intramural course), and point out the critical relevance of understanding the variable mechanisms of coronary dysfunction, especially, fixed versus phasic stenoses or intermittent spasm, and individual severity of clinical presentations.