Non-compaction of the right atrium and left ventricle in Ebstein's malformation.

Ebstein's malformation (EM) is characterized by dysplasia and displacement of the tricuspid inferior and septal leaflets from the true atrioventricular (AV) junction. Left ventricular hypertrabeculation/non-compaction (LVHT) including the 'atrialized' portion in EM has not been described. A 42-year-old man with a history of radiofrequency ablation of a Mahaim-like bundle suffered from chest pain. Coronary angiography was normal, but echocardiography showed a septal tricuspid leaflet inserting 3.5-cm apically beyond the AV junction, deep recesses of the atrialized interventricular septum, and a heavily trabeculated left ventricle; these were confirmed by cardiac magnetic resonance imaging. Neurologically, hypoacusis, positive pyramidal signs, postural tremor and brisk tendon reflexes were identified.