Poutanen T, Tikanoja T, Jääskeläinen P, Jokinen E, Silvast A, Laakso M, Kuusisto J. Diastolic dysfunction without left ventricular hypertrophy is an early finding in children with hypertrophic cardiomyopathy-causing mutations in the beta-myosin heavy chain, alpha-tropomyosin, and myosin-binding protein C genes.
Am Heart J 2006;
151:725.e1-725.e9. [PMID:
16504640 DOI:
10.1016/j.ahj.2005.12.005]
[Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Accepted: 12/06/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES
We investigated the presence of left ventricular hypertrophy (LVH) and features of diastolic dysfunction in genotype-confirmed children from families with hypertrophic cardiomyopathy (HCM) and healthy control children.
BACKGROUND
In subjects with HCM-causing mutations, LVH usually does not evolve until adolescence. Diastolic dysfunction has not been systematically evaluated in children carrying HCM-causing mutations.
METHODS
All children (aged 1.5-16.7 years) from 14 HCM families with identified disease-causing mutations (the Arg719Trp mutation in the beta-myosin heavy chain gene [MYH7], the Asp175Asn mutation in the alpha-tropomyosin gene [TPM1], the Gln1061X mutation in the myosin-binding protein C gene [MYBPC3], and the IVS5-2A-->C mutation in the MYBPC3 gene) and 53 matched control children were examined with electrocardiography and 2- and 3-dimensional echocardiography (2DE and 3DE). Natriuretic peptides were measured in children from HCM families and 67 control children.
RESULTS
Of 53 children from HCM families, 27 (51%) had a disease-causing mutation (G+). G+ children had slightly thicker septum on 2DE compared with the control children (P = .004), but only 3 (11%) of 27 G+ children exceeded the 95th percentile values of the body surface area-adjusted maximal LV thickness of healthy children (the major echocardiographic criterion for HCM). However, prolonged isovolumetric relaxation time, increased left atrial volume on 3DE, or increased levels of NT-proANP, all features suggestive of diastolic dysfunction, were found in 14 (52%) of 27 G+ children.
CONCLUSIONS
In children with HCM-causing mutations, signs of diastolic dysfunction are found in about half of the cases, as LVH is present only in small percentage of these children.
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