Electrophysiologic study of the condition system in normal children.

Values for cardiac conduction intervals obtained from normal children are reported so that the data will be available for comparison with patients who are suspected of having abnormalities. Sinus node recovery time correlated linearly with the resting PP interval. The mean intra-atrial conduction was considerably shorter in children (less than 25 msec) than in adults (42 msec). The atrioventricular node had similar electrophysiologic properties in the child and adult. With aging, the His bundle to Purkinje fiber time increased significantly (P less than .01).