THE QRS VECTORCARDIOGRAM OF THE NORMAL NEWBORN HUMAN.

A four-electrode resistance-combined network system was used to record the vector-cardiograms of 15 full-term infants, from birth to 96 hours of life. In the horizontal plane the QRS loop was described in a clockwise manner anterior to the point of origin. Initially it was directed anteriorly to the left and, terminally, posteriorly to the right. In the sagittal plane the loop described a figure-of-eight, with minimal superior and inferior displacement of the anterior and posterior components. In the frontal plane the QRS vector loop was described in either a clockwise direction inferior to the point of origin or a clockwise direction superior to the point of origin. Alterations in the appearance of the QRS vectorcardiogram result from changes in spatial orientation.