CM recognized as dystinct type in 2006, normally LV is more affected (and is called LVNC) but both ventricle could be abnormal, LVNC is a structural abnormality of the left ventricular myocardium of uncertain etiology and it is speculated that it results from a disturbed compaction process during early development of the LV myocardium. Neuromuscular disorders and chromosomal defects are noted (as example, Barth’s syndrome).  It is recommended that first degree relatives of patients with LVNC be investigated for LVNC. Diagnosed is done by Echo (different criteria are used for the diagnosis, see Figure below) that shows prominent trabeculae, intertrabeculae recesses and 2 distinct layers of myocardium (compacted and no compacted). although cardiac MRI is the gold standard test for diagnosis.

The outcome of patients with LVNC is usually determined by the development of complications, including ventricular arrhythmias, heart failure, and thromboembolism. The frequency of thromboembolism has been reported to range from 13% to 24% in adults and 0% to 38% in children.