Distribution of Hypertrophy and Late Gadolinium Enhancement in Children and Adolescents with Hypertrophic Cardiomyopathy

Background: While well characterized in adult patients, the pattern of hypertrophy and the extent of myocardial scarring in hypertrophic cardiomyopathy (HCM) are insufficiently known. The aim of this study was to assess the hypertrophy patterns and the prevalence and clinical significance of scars in the hearts of young patients with HCM. Methods and Results: A retrospective analysis of the imaging findings of 38 children (aged 12.83 ± 2 years, 30 males) with HCM who underwent cardiac magnetic resonance imaging (CMR) was performed. In addition to left ventricular mass and volumes, the examinations were assessed for the pattern of hypertrophy and presence of late gadolinium enhancement (LGE). A myocardial signal intensity≥6 standard deviations above the mean of normal myocardium defined positive LGE. Left ventricular mass index averaged 110 ± 34 g/m². Nineteen children (50%) had diffuse septal, 13 (34%) diffuse concentric and 6 (16%) isolated basal hypertrophy. Seven children (18%) had LGE. Patients with LGE had a greater left ventricular mass index than those without (136 ± 34 g/m² vs. 104 ± 31 g/m², P = .025). The only two patients who presented with an episode of aborted sudden cardiac death had LGE (P = .03). Conclusions: The most common hypertrophy pattern in children with HCM was diffuse septal hypertrophy. The incidence of LGE observed is lower than that reported in adults. The presence of LGE appears to confer a risk for adverse events.