Endomyocardial fibroelastosis is a cause of unexplained childhood cardiac insufficiency. It results from diffuse thickening of the endocardium leading to dilated myocardiopathy in the majority of cases and restrictive myocardiopathy in rare cases. It may occur as a primary disorder or may be secondary to another cardiac malformation, notably aortic stenosis or atresia.

The formation of a blood clot inside a blood vessel that subsequently travels through the blood stream from the site where it formed to another location in the body, generally leading to vascular occlusion at the distant site.