Dextrorotation of the Heart

Dextrorotation of the heart is a morphologic entity characterized by rotation to the right in both frontal and transverse planes of the body; the relative location of the cardiac chambers is normal. In contrast to mirror-image dextrocardia, which results from a defect in lateralization of the entire embryo occurring in the first 10 days of fetal life, dextrorotation results from a teratogenic agent acting in the sixth fetal week. More than 75 per cent of the patients with dextrorotation in this series had associated congenital cardiac anomalies. Corrected transposition of the great vessels was present in eight of 41 patients. A normal electrocardiogram provided a clear differentiation from mirror-image dextrocardia; angiocardiography permitted precise analysis of the in-vivo morphology.