All issues > Volume 35(12); 1992

Original Article

J Korean Pediatr Soc. 1992;35(12):1696-1701. Published online December 15, 1992.

A Cause of Transient Systolic Murmur in Neonates Physiologic Pulmonary Artery Stenosis

Hyun Joo HJ Kwak¹, Phil Seob PS Sim¹, Kwang Chul KC Lee¹, Chang Sung CS Sohn¹, Joo Won JW Lee¹, Young Chang YC Tockgo¹

¹Department of Pediatrics, College of Medicine, Korea University, Seoul, Korea

Abstract

A transient heart murmur is frequently heard in normal newborn who has no congenital heart disease. The cause of this murmur remains unclear but was speculated as hypoplasia of the pulmonary arterial branches or unusual alignment of the main pulmonary artery with its branches. Pulsed Doppler and two-dimensional echocardiographic studies were undertaken in 19 newborn infants with a transient murmur and 13 infants without heart murmur and their pulmonary arterial peak flow velocity and diameters were evaluated. The peak flow velocity of right and left pulmonary artery in neonates with murmur were significantly higher than in neonates without murmur and the ratio of the diameter between right and left pulmonary artery to that of a main pulmonary artery in neonates with murmur group is smaller than in neonates without murmur. The results demonstrated that the transient functional systolic murmur in neonates was considered most likely due to the relatively small size of pulmonary artery branches, disproportional to that of the main trunk.

Keywords :Transient murmur, Peripheral pulmonary stenosis