Endocardial fibroelastosis has been classified as primary and secondary. 

In the primary type, there is no structural cardiac abnormality, whereas, in the secondary type, a cardiac abnormality is demonstrable.

The most common secondary causes of endocardial fibroelastosis are aortic stenosis, coarctation of the aorta, anomalous origin of the left coronary artery from the pulmonary trunk, metabolic disorders, and viral infections.