Familal left ventricular hypertrabeculation (noncompaction) is myopathic.

BACKGROUND

Left-ventricular hypertrabeculation/noncompaction(LVHT) is a cardiac abnormality of unknown aetiology, frequently associated with arrhythmias, heart failure, and embolism. In most cases LVHT is associated with neuromuscular disorders (NMDs) or other rare non-neuromuscular genetic syndromes. Occasionally, LVHT occurs familiarly.

METHODS AND RESULTS

Invited for a cardiologic investigation were all first-degree relatives of index patients with LVHT who attended the cardiologic department. Altogether 25 relatives of 15 index patients from 15 families were investigated. Three members each were investigated in 3 families, 2 patients each in 4 families and 1 member each in 8 families. Among the 25 relatives from the 15 families, LVHT was found in 4 of them. Accordingly, familial LVHT was detected in 4 of the 15 investigated families (27%). Among the 4 relatives with LVHT, extension and morphology were similar to the appropriate index patient in 2 families. A NMD was diagnosed in three of the four relatives (75%) with familial LVHT. One relative without LVHT presented with a history of Fallot's tetralogy, and two relatives each presented with thickening of the left-ventricular myocardium.

CONCLUSIONS

LVHT is familial in at least 27% of the patients with LVHT. LVHT may differ between relatives in some of the patients with familial LVHT. Familial LVHT is associated with a NMD in the majority of the cases. Relatives of LVHT patients may present with cardiac abnormalities other than LVHT.