Electrocardiogram of the premature infant at 1 year of age.

ECGs were examined from 461 premature infants at 1 year of age. Data from those without a history of bronchopulmonary dysplasia were generally similar to published norms for healthy 1-year old infants. History and persistence of residual lung disease were reflected in the ECG by a high prevalence of findings suggestive of right ventricular hypertrophy. Clinically significant patent ductus arteriosus during the neonatal period did not influence the 1-year ECG findings. The data expand the published experience with follow-up ECGs from premature infants and suggest that the ECG may be a useful tool in follow-up of chronic residual lung disease in this population.

Ultrasound detection and quantitation of left to right aortopulmonary shunt flow in a canine model.

To test the sensitivity and accuracy of pulsed Doppler ultrasonography to detect and quantitate left to right aortopulmonary shunt flow, an arterial allograft aortopulmonary anastomosis was constructed in nine adult mongrel dogs. Cardiac output and allograft flow were measured as the diameter of the allograft was varied. Piezoelectric crystals attached to the carotid artery and proximal descending aorta were energized with 20 MHz pulsed Doppler signals. Negative Doppler shift and negative Doppler shift/positive Doppler shift were calculated for seven dogs. All dogs exhibited negative Doppler shift in the carotid artery at zero allograft flow; five of the seven dogs exhibited a similar pattern in the descending aorta. Increasing negative Doppler shift was measured in all dogs from both sites as the allograft flow increased. Excellent linear correlation existed between allograft flow and negative Doppler shift and negative Doppler shift/positive Doppler shift for each dog from both sampling sites. However, marked interanimal variation in the slopes of the linear regression lines existed, making the composite linear correlation very poor. Detection of small left to right aortopulmonary shunting and single measurements to quantitate accurately left to right aortopulmonary shunting introduce errors due to intersubject variation. However, these results suggest that serial ultrasound measurements made over a short time can accurately predict changes in left to right aortopulmonary shunting.

Radionuclide diagnosis of infradiaphragmatic total anomalous pulmonary venous drainage.

We hypothesized that infradiaphagmatic total anomalous pulmonary venous drainage (ITAPVD), because of its unique physiology, could be diagnosed with radionuclide angiography. Seven neonates with severe respiratory distress were injected intravenously with 3 mCi technetium-99m pertechnetate. In each of four neonates demonstrated to have ITAPVD by pulmonary angiography, nuclide recirculation through the right atrium occurred 3-6 s after initial passage. In addition, direct visualization of the anomalous common pulmonary trunk with nuclide as a "tail" below the diaphragm was obvious in the third infant studied. This prompted review of the first two infants with ITAPVD; in retrospect the anomalous trunk was also visualized with nuclide in both of these infants. All three were injected via the upper extremity. In the fourth ITAPVD infant, nuclide was injected via the lower extremity. In that infant, preferential streaming of the inferior vena caval flow and nuclide across the foramen ovale into the left heart led to simultaneous opacification of anomalous trunk and descending aorta, obscuring the "tail" sign.

Aortic atresia with double inlet left ventricle, rudimentary left sided right ventricle, and ventriculoarterial discordance.

Aortic atresia associated with ventriculoarterial discordance (transposition) was found at necropsy in a 3 month old neonate. This is a rare association.

Infradiaphragmatic total anomalous pulmonary venous drainage: new diagnostic, physiologic, and surgical considerations.

Numerous diagnostic pitfalls were noted among 6 infants with infradiaphragmatic total anomalous pulmonary venous drainage, including prolonged moderate respiratory distress in 2 infants, normal cardiac examination in 2, normal electrocardiograms in 2, arterial PO2 in excess of 100 torr in 3 cases, right radial/umbilical arterial PO2 gradients consistent with significant right-to-left ductal shunting in 2 of 4 cases, misleading M-mode echocardiography in 2 of 4 cases, and missed diagnosis at initial cardiac catheterization despite pulmonary angiography in 1 case. Helpful radiographic features included small heart, congested lungs, and pleural effusions in all 6 cases, and visualization of the anomalous trunk overlying the liver on slightly rotated abdominal flat plates in both cases so examined. Bedside umbilical venous catheterization was pathognomonic in 3 cases and suggestive of the diagnosis in the fourth case. Cross-sectional echocardiography was diagnostic in the 1 case in which it was employed. Intraoperative and postoperative pulmonary hypertension led to the demise of the 4 infants who survived long enough to undergo surgery. In addition to early diagnosis, measures to insure maximal decompression of the pulmonary circuit at surgery should improve survival.

Pleural effusion in the first days of life: a prospective study.

In a thirty-month prospective study pleural effusions were found on chest radiographs in 33 of 1482 newborns admitted to intensive care units. Congenital heart disease was the most common cause, accounting for eleven cases. Meconium aspiration was the most common respiratory disease associated with neonatal pleural effusion. Infants whose effusions were first noted after the second day of life were likely to have heart disease (p = 0.02). Infants with moderate or large effusions were unlikely to have heart disease (p = 0.04). Prolonged pleural effusion was associated with a prolonged need for supplemental oxygen. Survivors whose effusions lasted three or more days were at increased risk for needing supplemental oxygen for more than twenty-one days (p = 0.07). The overall mortality was 48 percent (sixteen of thirty-three infants died).

Cardiac catheterization in infants through a venous cutdown sheath.

When percutaneous vascular access for cardiac catheterization of small infants fails, necessitating a cutdown approach, we cannulate the isolated vein (usually the great saphenous vein) with a guidewire, dilator, and sheath with subsequent introduction of the catheter through the indwelling sheath. We have used this technique in sixty-one infants without complications and recommend this modified sheath approach because of the following advantages: ease of introduction of the introducer set and catheter, the ability to change catheters quickly, elimination of distal vascular spasm, reduction of vascular trauma induced by catheter manipulation, prevention of backflow bleeding at the catheter entry site, and possible reduction of catheterization time.

Respiratory suppression and swallowing from introduction of fluids into the laryngeal region of the lamb.

Introduction of 0.9% NaCl or undiluted fetal tracheal fluid into the laryngeal region produced no suppression of breathing in lambs during the perinatal period. As NaCl or tracheal fluid solutions were increasingly diluted with water, progressively greater respiratory suppression associated with rapid swallowing was observed. Introduction of amniotic fluid was associated with variable suppression of respiration. The swallowing induced by the dilute solutions was as rapid as two swallows per sec. Lambs 3 months of age swallowed when water was introduced into the laryngeal region, but were able to alternate swallows between breaths without suppression of breathing.