ABSTRACT
BACKGROUND: The primary mode of imaging in hypertrophic cardiomyopathy (HCM) is transthoracic echocardiography (TTE). However, in adults inadequate acoustic windows lead to poor quantification of myocardial thickness compared with cardiac magnetic resonance (CMR) imaging. In comparison, children have better acoustic windows and TTE measurements of wall thickness might be more accurate. The aim of this study was to assess the performance of TTE compared with CMR for the assessment of myocardial thickness in children with HCM. METHODS: Nineteen children (median age, 12.7 years; range, 8.4-18.4 years) with known HCM were studied using TTE and CMR imaging on the same day. The left ventricle was measured off-line using the standard 16-segment model. RESULTS: With CMR imaging 304 (19 × 16) segments were analyzable whereas only 263 were analyzable using echocardiography. Wall thickness measurements according to TTE were greater than those according to CMR imaging in the basal anterolateral, midventricular anterior and anterolateral and apical inferior, lateral and septal segments and smaller for the midventricular inferior and inferoseptal segments. Reproducibility of CMR and TTE measurements was assessed using the intraclass correlation coefficient (ICC). CMR measurements showed excellent intrareader (ICC, 0.929-0.991) and moderate inter-reader (ICC range, 0.512-0.991) reproducibility. TTE measurements revealed moderate intrareader (ICC, 0.575-0.942) and poor inter-reader (ICC range, -1.02 to 0.939) reproducibility. CONCLUSIONS: Echocardiography incompletely assesses circumferential myocardial thickness in a proportion of pediatric patients with HCM. Echocardiography under- and overestimates maximum wall thickness compared with CMR, depending on the location. Measurements using CMR are more reproducible than those obtained using echocardiography.
Subject(s)
Cardiomyopathy, Hypertrophic/diagnosis , Echocardiography/methods , Magnetic Resonance Imaging/methods , Adolescent , Canada , Child , Comparative Effectiveness Research , Dimensional Measurement Accuracy , Female , Humans , Male , Myocardium/pathology , Reproducibility of ResultsABSTRACT
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/m(2) . 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/m(2) vs. 104 ± 31 g/m(2) , 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.
