Familial occurrence of isolated non-compaction cardiomyopathy

Isolated left ventricular non-compaction cardiomyopathy (LVNC) may have an autosomal dominant or X-linked recessive inheritance. We focus on the familial occurrence of LVNC after misdiagnosing this disorder in symptomatic patients in two families. After identification of the index patient we studied the families more intensively in order to unmask affected family members.

LVNC was defined as an end-systolic non-compacted subendocardial layer of the left ventricular wall of at least twice the thickness of the subepicardial compacted layer (2D echocardiogram and MRI). This was studied in 13 patients in 2 families (A and B). LVNC was found in 3 out of 11 patients in family A. The grandmother was asymptomatic. Her daughter suffered from recurrent syncope and heart failure. Her daughter received a cardiac transplant because of progressive heart failure at the age of 14years. In family B, LVNC was found in 2 patients, a father and his son and presumed in a brother and a sister of the father who died suddenly at the age of 17 and 21years, respectively.

In all symptomatic patients, proven LVNC was previously misdiagnosed as hypertrophic or dilated cardiomyopathy. Misdiagnosis may lead to insufficient treatment and will misdirect targeted molecular genetic analysis. LVNC was identified in seven patients in two families. Family screening may unmask affected family members for primary prevention including anti-coagulation and ICD-therapy.