The Genesis and Importance of the Electrocardiogram in Coarctation of the Aorta

Abstract

The electrocardiogram in uncomplicated coarctation of the aorta in infants reflects the pattern of the fetal circulation and serves as a useful prognostic guide. When the fetal ductus inserts proximally to the region of coarctation and closes at birth, right ventricular enlargement is present at birth but is retrogressive. Furthermore, in this situation collateral circulation has begun to develop before birth so that the left ventricle can compensate on assumption of the postnatal circulation, and the prognosis is good. When the insertion of the fetal ductus is distal to the coarctation, progressive, and frequently fatal, left ventricular enlargement and failure develop shortly after birth. Modifications of these electrocardiographic patterns in the production of right bundle branch block are also discussed and illustrated.