Left ventricular noncompaction associated with hypertrophic cardiomyopathy: echocardiographic diagnosis and genetic analysis of a new pedigree in China

Background: Hypertrophic cardiomyopathy (HCM) and left ventricular noncompaction (LVNC) are both genetically determined and familial diseases that possess variable but overlapping genetic defects. Previous literature has mostly reported their occurrences as either separate disorders in different members of a family or coexisting entities in sporadic cases rather than familial cases. This study explored the echocardiographic diagnostic values and familial features in a family with coexistence of HCM and LVNC.

Methods: A four-generation family comprised of 30 members was studied; 28 members underwent familial screening by routine transthoracic echocardiography (TTE), contrast echocardiography (CE), and/or cardiac magnetic resonance imaging (cMRI). Echocardiographic and cMRI findings were then compared.

Results: Four members (13.3%) died of sudden death or heart failure. Eleven members (39%) suffered from HCM, LVNC or both. There were 13 left ventricular hypertrophic segments among the echocardiographic images of 9 locally archived patients, including septal, inferior and anterior wall segments (8, 3, 2 respectively) as well as 20 noncompaction segments, including lateral, apical, anterior, antero-septal and inferior wall segments (8, 5, 4, 2, 1 respectively). Left atrial dilatation and diastolic dysfunction were significant in these subjects. Findings from TTE and CE were in accordance with those from cMRI in lesion locations. CE provided more information about noncompaction segments located in the antero-septum and near field than TTE.

Conclusions: HCM and LVNC coexist in one Chinese family, with overlapping phenotypes and different ages, clinical manifestations and multimodality imaging findings. TTE is an excellent tool to diagnose HCM and LVNC with supplementation by CE.