Early Left Ventricular Abnormalities in Children with Heterozygous Familial Hypercholesterolemia

Abstract

Few data are available on cardiac morphology and function in children with heterozygous familial hypercholesterolemia (FH). Such patients represent a unique clinical model to assess the effect of pure hypercholesterolemia on cardiac morphology and function, excluding the effect of comorbidities. Speckle-tracking echocardiography, a relatively new echocardiographic modality, allows the assessment of myocardial deformation properties. The aim of this study was to define in children with FH the preclinical effects of isolated hypercholesterolemia on the cardiovascular system by examining left ventricular (LV) function using speckle-tracking echocardiography. Ninety children (45 with FH and 45 controls; mean age, 11 ± 3 years) were prospectively studied. Children with FH showed thicker LV walls and significantly higher LV mass indexed for height(2.7) (P= .0008) and for body surface area (P < .0001). LV ejection fractions were similar in both groups. Assessment of diastolic function demonstrated longer deceleration times (P < .0001), reduced early diastolic mitral annular velocities (P < .0001), and higher transmitral early/early diastolic mitral annular velocity ratios (P= .0003) in children with FH. Longitudinal and circumferential myocardial deformation of the left ventricle were significantly reduced (P < .0001) whereas radial deformation was increased in children with FH (P= .04) compared with controls. This study demonstrates that hypercholesterolemia is associated with significant LV morphologic and functional alterations during childhood. The findings also suggest that reductions in longitudinal and circumferential deformation are compensated for by increasing radial strain in children with FH with normal LV ejection fractions. This study raises the questions of the clinical importance of these findings and the opportunity for cholesterol-lowering therapy. The potential benefits and risks of such treatment at a young age need to be addressed in larger long-term studies.