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Objective: To test the hypothesis that neonates with symptomatic tetralogy of Fallot (TOF) and absent ductus arteriosus (ADA) have worse clinical outcomes compared with those with a ductus arteriosus (DA), and that this difference is driven by those born with ADA and with critically deficient pulmonary blood flow (CDPBF)., Study Design: We performed a retrospective, multicenter cohort study of neonates who underwent intervention for symptomatic TOF comparing death and reintervention between subjects with and without a DA identified on fetal echocardiogram or on echocardiogram performed in the first postnatal day. Exclusion criteria were as follows: inability to define DA status, collaterals supplying pulmonary blood flow, atrioventricular septal defect, and absent pulmonary valve. We defined CDPBF as undergoing a procedure to augment pulmonary blood flow on the date of birth or extracorporeal membrane oxygenation prior to such a procedure., Results: The study cohort included 519 patients, among whom 11% had ADA. Patients with ADA were more likely to have a genetic syndrome and had smaller branch pulmonary artery size. In analyses adjusting for center, interventional treatment strategy, genetic syndrome, and minimum branch pulmonary artery size, ADA was associated with higher mortality risk (adjusted hazard ratio of 2.37 (95% CI: 1.07,5.27; P = .034). Seven patients had CDPBF (1.3% of the entire cohort and 12% of patients with ADA)., Conclusions: A minority of symptomatic TOF neonates have ADA, which is associated with higher adjusted mortality risk compared with those with a DA. CDPBF appears to be a rare but important entity in this population., Competing Interests: Declaration of Competing Interest This research is supported, in part, by donations to the Congenital Cardiac Research Collaborative from the Kennedy Hammill Pediatric Cardiac Research Fund, Liam Sexton Foundation, and A Heart Like Ava. The authors declare no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: To determine the effect of lung recruitment on pulmonary, systemic, and ductal blood flow in preterm infants treated with primary high-frequency ventilation (HFV)., Study Design: Thirty-four infants (median gestational age, 28 weeks) were included in this prospective cohort study. Changes in oxygenation in response to stepwise changes in the continuous distending pressure (CDP) were used to monitor lung recruitment during HFV. For each individual patient, the opening pressure (CDPo), closing pressure (CDPc), and optimal pressure (CDPopt) were determined. Ultrasound measurements of right ventricular output (RVO), superior vena cava (SVC), and ductus arteriosus (DA) flow were performed at the start of recruitment (CDPs), CDPo, and CDPopt., Results: Increasing the CDP from 8 (CDPs) to 20 (CDPo) cmH(2)O resulted in a decreased RVO (mean difference, -17%; 95% CI, -24, -10%) and unchanged SVC flow and ductal shunting. Transient low RVO and SVC flow values at CDPo were seen in 3 and 2 infants, respectively., Conclusions: Lung recruitment during HFV in preterm infants does not appear to result in clinically relevant changes in pulmonary, systemic, and ductal blood flow.

Objective: To describe the relationship among ductal shunting, estimated pulmonary blood flow, and pulmonary hemorrhage in very preterm infants., Study Design: A total of 126 babies born before 30 weeks' gestation (median gestation 27 weeks, range 23 to 29 weeks) underwent echocardiography at 5, 12, 24, and 48 hours of age; measurements included right and left ventricular output, superior vena cava flow, and color Doppler diameter of any ductal shunt. Pulmonary blood flow was derived from the sum of right ventricular output and estimated ductal shunt flow., Results: Twelve (9.5%) babies had a pulmonary hemorrhage at a mean age of 38 hours. Compared with the rest of the cohort, these 12 babies were less likely to have had antenatal steroids (59% vs 90%) and were less mature (26 weeks vs 27 weeks). At the echocardiogram closest to the pulmonary hemorrhage, 11 (92%) of the 12 babies had a significant patent ductus arteriosus >1.6 mm in diameter (median 2 mm, range 0.7 to 2.4 mm), and the median pulmonary blood flow was 326 mL/kg/min (range 210 to 598 mL/kg/min). These measurements were significantly higher than those found in the rest of the cohort in the same period (median duct diameter 0.5 mm [range 0 to 2.9 mm], median pulmonary blood flow 237 mL/kg/min [range 107 to 569 mL/kg/min]). At 5-hour echocardiography the babies with pulmonary hemorrhage had significantly larger diameter ducts but similar pulmonary blood flow., Conclusions: Pulmonary hemorrhage in preterm babies is associated with significant ductal shunting and high estimated pulmonary blood flow.

Objective: To assess the contribution of cardiac output in determining the blood pressure of preterm infants and to identify other factors that may be important., Methods: Sixty-seven preterm infants requiring mechanical ventilation (median birth weight, 1015 gm: median gestational age, 28 weeks) underwent on echocardiographic study at on average age of 19 hours (range, 7 to 31 hours). Measurements taken included left ventricular ejection fraction, left and right ventricular outputs by means of pulsed Doppler and the diameter of both the ductal and atrial shunt jets with the use of color Doppler as a measure of the size of shunt. Simultaneous measurements of intraarterial blood pressures, mean airway pressure, and inspired fraction of oxygen were recorded., Results: After we allowed for the influence of ductal shunting, the correlation between the left ventricular output and mean arterial blood pressure was significant but weak (r = 0.38). There were infants with low blood pressures and normal cardiac outputs, and conversely there were infants with low cardiac outputs and normal blood pressure. The infants with a mean arterial blood pressure of less than 30 mm Hg had a significantly lower gestational age (27 vs 28 weeks), higher mean airway pressure (9.0 vs 7.0 cm H2O), larger ductal diameter (1.6 mm vs 0.7 mm) and a lower systemic vascular resistance (163 vs 184 mm Hg/L per minute per kilogram of body weight). Multilinear regression identified higher mean airway pressure and larger ductal diameter as significant negative influences on mean arterial blood pressure, with higher gestational age and higher left ventricular output as significant positive influences., Conclusions: Normal blood pressure cannot necessarily be equated with normal systemic now. These data emphasize the importance of other influences, and in particular that of varying systemic vascular resistance, in the determination of blood pressure in preterm infants.

Objective: To identify early echocardiographic markers allowing prediction of subsequent symptomatic patent ductus arteriosus (PDA)., Methods: One hundred sixteen preterm infants ( < 1500 gm) requiring mechanical ventilation underwent echocardiography at a mean postnatal age of 19 hours (range, 7 to 31 hours). Four potential markers were studied: the left atrial to aortic root ratio, pulsed Doppler signal within the course of the duct (ductal diameter), and the direction of postductal aortic diastolic flow. Subsequent ductal closure or significant patency (if suspected clinically) was confirmed echocardiographically., Results: A significant PDA developed in 42 infants (36%). Ductal diameter was the most accurate echocardiographic marker in predicting subsequent significant most accurate echocardiographic marker in predicting subsequent significant PDA. With a ductal diameter of 1.5 mm or greater there were 34 true-positive, 11 false-positive, 63 true-negative, and 8 false-negative results, giving a positive likelihood ratio of 5.5 and a negative likelihood ratio of 0.22 for prediction of development of a PDA requiring treatment. The sensitivity was 81% and the specificity was 85%. Only one infant older than 28 weeks of gestational age had a significant PDA, and limiting the analysis to infants younger than 29 weeks of gestation further improved the predictive accuracy of ductal diameter. The positive likelihood ratio was 8.1 and the negative likelihood ratio was 0.19, with a sensitivity of 83% and a specificity of 90%., Conclusion: Color Doppler measurement of the internal ductal diameter allows early prediction of significant PDA in preterm infants.

Objective: To examine the role of ductus arteriosus (DA) constriction and loss of luminal blood flow in producing permanent closure of the DA in human infants., Methods: We studied 77 newborn infants (gestational age, 23 to 33 weeks) with asymptomatic patent ductus arteriosus (PDA), who had "complete clinical closure" (defined as the disappearance of all PDA signs) after treatment with indomethacin (three doses within 36 hours). All infants had an echocardiogram 24 to 36 hours after the last dose of indomethacin. They were then followed for the development of ductus reopening., Results: Despite the absence of clinical signs, 18 (23%) of 77 infants still had some residual luminal blood flow according to their echocardiograms. The failure to obliterate luminal blood flow completely was directly related to the infant's postnatal age when treatment was begun and to the amount of fluid administered before treatment. Subsequently the DA reopened in 16 (21%) of 77 infants. As predicted, infants with residual luminal blood flow after indomethacin treatment had a higher rate of subsequent clinical reopening than did those with no luminal flow. In addition, immature infants had a significantly higher reopening rate than did more mature infants. The increased risk of reopening in immature infants was seen even when indomethacin caused complete obliteration of ductus luminal blood flow., Conclusion: The DA of immature infants is resistant to the constriction-induced ischemic damage that is necessary for subsequent permanent closure of the vessel.

Seventeen term newborn infants (control subjects) and 17 whose mothers had been given intravaginal doses of prostaglandin E2 (PGE2) were examined serially by color Doppler echocardiography to determine whether maternal PGE2 prolonged ductal patency. No clinically relevant differences in closure times were found. Low-dose intravaginal PGE2 therapy was not associated with prolonged ductal patency in term infants.

Attention is called to a poorly recognized syndrome of neonatal renal arterial embolism, presumably from the ductus arteriosum, resulting in malignant hypertension, congestive heart failure, respiratory distress, and increased renin secretion. Radiographic studies revealed a ductus diverticulum and multiple narrowed arteries including the lower pole branches of the right renal artery. Renal scan showed poor imaging of the lower pole of the right kidney. Nephrectomy resulted in a prompt return of the blood pressure into the normal range. Eight cases recorded in the literature resemble the one reported here, and six of the eight had an associated thrombosis of the ductus arteriosum. Our patient appears to be the first case recognized by modern techniques followed by nephrectomy and clinical cure.