Noninvasive recording of the His bundle electrogram in neonates.

Twenty-seven normal, nonsedated neonates had high-resolution electrocardiography performed during the first four days of life. Using high amplification, analogue and digital filters, and signal averaging, easily defined His bundle deflections of 0.75-7.75 (mean 2.5) microV were detected in 25 (92.6%) of the 27 babies. The PH interval was 60-105 (mean 83) ms and the HV interval 10-25 (mean 17) ms. Surface His bundle electrocardiography is easily performed in the neonate and, as might be predicted, conduction intervals are considerably shorter than those seen in older age groups.