Transient solitary diastolic murmurs in the newborn.

Three newborn infants were observed to have murmurs restricted to diastole. None was considered ill, and none has exhibited symptoms or findings of cardiopulmonary disease throughout follow-up. Localization of the diastolic timing and absence of a significant systolic component of the murmur were confirmed by phonocardiography. The transient nature of the finding was established by serial phonocardiography. Essentially normal cardiac anatomy was determined by routine chest radiograms, electrocardiograms, and echocardiography in both M and two-dimensional modes. Suggestive evidence for left-to-right shunting was present in each case. Invasive studies were not performed. An anatomic cause for the diastolic murmur was not discovered, suggesting it could be related to the ductus arteriosus or mild pulmonary insufficiency.