Misdiagnosis of aortic atresia due to catheter malposition.

A single film portable aortogram through a highly placed umbilical artery catheter suggested aortic atresia, but subsequent study revealed a normal aorta and a patent ductus arteriosus. This demonstrates the importance of proper catheter placement in single film portable aortography, which is a reliable diagnostic tool in the evaluation of distressed neonates.

The cardiovascular effects of dopamine in the severely asphyxiated neonate.

The cardiovascular effects of dopamine were evaluated in 14 severely asphyxiated neonates. After a period of stabilization, either dopamine 2.5 micrograms/kg/minute or placebo was infused in a randomized double-blind protocol. In seven dopamine-treated infants, echocardiographically determined shortening fraction and mean velocity of circumferential fiber shortening increased when compared to preinfusion values (P less than 0.05). There was no significant change in these echo indices of cardiac function in the placebo-treated group. Systolic blood pressure rose in the dopamine group when compared to predopamine infusion values and to the postinfusion values of the placebo group (P less than 0.001 and 0.025, respectively). Diastolic blood pressure increased to a small degree in the dopamine group. There was no significant change in heart rate or echocardiographically measured systolic time intervals. Low doses of dopamine increase cardiac performance and raise systolic blood pressure in the severely asphyxiated neonate.

Two-dimensional echocardiographic evaluation of discrete subaortic stenosis from the apical long axis view.

M-mode standard two-dimensional (2DE) left parasternal long axis echocardiographic examination of the left ventricular outflow tract (LVOT) was evaluated exclusively with respect to its utility in identifying discrete subaortic stenosis (SUB-AS). Important details of the anatomy of the subaortic area may also be obtained from 2DE apical long axis imaging. According, 18 patients with discrete SUB-AS were prospectively evaluated by M-mode and 2DE. The M-mode findings included narrowing of the LVOT and early systolic closure of the aortic valve. However, these findings were variable and highly dependent upon scan speed, fluid flow dynamics, and beam angulation. 2DE findings varied using the standard long axis view at the left parasternal border, depending upon the type of obstruction present. A discrete membrane produced linear echoes adjacent and parallel to the interventricular septum beneath the aortic valve. Fibromuscular obstruction produced a localized dense ridge of echoes in the LVOT. These findings were not apparent in five patients studied. In these patients, the 2DE apical long axis view was employed to image the subaortic area. From this tomographic corss-section a fibrous membrane was imaged as a linear echo parallel to the aortic valve. The membrane extended across the LVOT from the ventricular septum to the anterior leaflet of the mitral valve. The 2DE apical long axis view therefore provides an additional approach in the evaluation of patients with discrete SUB-AS.

Assessment of patent ductus arteriosus in preterm infants by single lateral film aortography.

Differentiation of a hemodynamically significant cardiovascular abnormality from lung disease in the newborn infant may remain problematic after clinical, radiographic, and echocardiographic evaluation. Single-view aortography was performed in 38 preterm and one full term infant in the neonatal special care nursery. Special lateral views were obtained consisting of either a horizontal x-ray beam with oblique angulation of the supine patient or a vertical bean with 30 degree head-up angulation of the patient. These views projected the ductus caudal to the aortic arch and enabled visualization of the entire length of the ductus and focal constrictions of the ductus. The severity of patent ductus arteriosus was judged by anatomic (diameter of the ductus compared to the descending aorta) and physiologic (preferential opacification of the aortic arch or pulmonary circulation) criteria.