Arrhythmic sudden cardiac death in a 3-year-old child with intimal fibroplasia of coronary arteries, aorta, and its branches

We report an unusual case of "arrhythmic" sudden cardiac death in a 3-year- old child who died of ischemic myocardial lesions as a result of intimal fi broplasia of the coronary arteries. Also affected were the aorta and its ma jor branches, whereas renal and mesenteric arteries, celiac mink, and syste mic veins were normal. Histopathologic examination showed severe concentric thickening of intima because of a proliferation of spindle-shaped cells (m esenchymal cells) set in an abundant extracellular matrix. In some vascular segments the intima was densely fibrotic and hyalinized. No significant in flammation, foam cells, cholesterol clefts, or other evidence of atheroma w ere present. The intimal lesions did not involve the media and/or the adven titia. Immunohistochemical staining of intima showed the proliferating mese nchimal cells to be myofibroblastic. Reactions for vimentin and smooth musc le actin were positive, while those for desmin, myosin, CD34, and Factor VI II were negative. (C) 2001 Elsevier Science Tnc. All rights reserved.