Left ventricular non-compaction, also known as LVNC, spongy myocardium or hypertrabeculation syndrome, is a pathologic cardiac condition in which the myocytes exhibit a “spongy” appearance. This is considered a genetic cardiomyopathy and is somewhat rare. The left ventricular myocardium exhibits pronounced trabeculae with intracavitary recesses, similar to diverticulum.
Diagnosis is made either via echocardiography or pathologically. The Jenni Criteria has been proposed as a 2:1 ratio of non-compacted cells to compacted cells in end-systole on the parasternal short axis echocardiographic view.
Manifestations include heart failure (frequently systolic), thromboembolism, arrhythmia and sudden cardiac death. Anticoagulation is recommended in all patients with LVNC with ejection fractions < 40% or if they develop atrial fibrillation. Medical therapy otherwise consists of standard heart failure therapy. Monitoring for arrhythmia is important and avoiding vigorous exercise is recommended.