Spontaneous left ventricular hypertrabeculation in dystrophin duplication based Becker's muscular dystrophy.

Background: Left ventricular hypertrabeculation is frequently associated with neuromuscular disorders. Whether left ventricular hypertrabeculation in these patients is congenital or develops during lifetime, is unknown.

Case Report: In a 65-year-old man with Becker's muscular dystrophy, due to a duplication in the dystrophin gene on chromosome Xq21 (dystrophin molecular weight: 500 kD), left ventricular hypertrabeculation was detected on transthoracic echocardiography although being absent in repeated previous echocardiographic examinations. Additionally, there was thickening of the left ventricular myocardium. The spontaneous occurrence of left ventricular hypertrabeculation was interpreted as progression of cardiac involvement in Becker's muscular dystrophy.

Conclusion: Left ventricular hypertrabeculation may not exclusively be congenital, but may occasionally develop spontaneously during lifetime, being interpreted as progression of cardiac involvement in Becker's muscular dystrophy.