The ductus arteriosus in healthy newborn infants studied by continuous Doppler guided by two-dimensional Doppler color echocardiography

To characterize the ductus arteriosus shunt after birth, 53 normal newborn infants (36-41 weeks gestation), appropriate in size for gestational age, were examined using two dimensional Doppler echocardiography directed continuous Doppler for evidence of patent ductus arteriosus. The infants were examined within six hours of birth, and every six-eight hours thereafter until ductus arteriosus shunt could no longer be detected. In 51/53 infants, an adequate examination was possible and ductus arteriosus was detected in every infant using the standard precordial approach. Using two dimensional Doppler echocardiography a yellow-orange-red jet, sometimes blue in the central area, directed at the lateral wall of the pulmonary artery was recorded; using continuous Doppler a diastolic or continuous spectral flow into the main pulmonary artery was recorded. Ductus arteriosus shunt could no longer be detected in 7 infants 12 hours after birth, in 26 infants 12-24 hours after birth, in 11 infants 24-36 hours after birth, in 5 infants 36-48 hours after birth and in 2 infants 48-60 hours after birth. A diastolic spectral Doppler flow was present in 38 infants and became continuous before duct closure in 27 infants. In 13 infants it was continuous at first examination and until the ductus arteriosus closure. Both diastolic or continuous spectral Doppler flow could present a flat waveform profile, or a protodiastolic or protosystolic peak velocity. The shunt peak velocity increased significantly with the age i.e. (1.5 +/- 0.7 m/sec mean and SD-), at first examination, vs 2.3 +/- 0.6 m/sec at last examination before ductus arteriosus closure (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Patency of the ductus arteriosus in normal neonates: two-dimensional echocardiography versus Doppler assessment

Two-dimensional echocardiography using a high resolution, 7.5 ,Jsz transduce was compared with Doppler echocardiography for the assessment of patency of the ductus arteriosus in normal newborn infants. Twenty-eight neonates were studied between 1 and 10 hours (mean 5.5) after birth and both examinations were possible in 27 (96%). Doppler echocardiography under two-dimensional direction indicated ductal patency in all 27 neonates. Doppler sampling in the pulmonary end of the ductus rather than the main pulmonary artery was more sensitive for detecting patency. When two-dimensional echocardiography only was used to predict patency, there was 85% sensitivity. Two-dimensional echocardiography showed no evidence of ductus arteriosus narrowing ion four neonates studied shortly after birth. In 18, the pulmonary portion of the ductus arteriosus appeared narrowed and in 8 of these, the narrowing extended toward the mid-portion of the ductus. In five others, there was only mid-ductus arteriosus narrowing. It is concluded that high resolution two-dimensional echocardiography can be used to assess ductus arteriosus morphology, but is limited in predicting ductal patency near the time of normal physiologic closure. Combined two-dimensional and Doppler echocardiography is a highly sensitive technique for detection of ductal patency when sampling is performed in the pulmonary end of the ductus arteriosus.     

Management of patent ductus arteriosus in preterm infants.

OBJECTIVE: To evaluate the incidence of symptomatic patent ductus arteriosus (PDA) in preterm infants, and the results of the intravenous indomethacine treatment and surgery. METHODS: Among 394 preterm infants (<37 weeks), symptomatic PDA was diagnosed by echocardiography in 51 babies and they were examined retrospectively. All infants were managed conservatively and then IV indomethacine was given to non-responders (n=30). Surgical closure was performed in 12 babies. RESULTS: The incidence of symptomatic PDA in preterm infants was 12.9%: median age: 3 days, mean birth weight: 1434+/-540 g (540-2900g) and mean gestational age (GA) 30.9+/-3.3 weeks (23-37 weeks). With indomethacine, ductal closure was achieved in 70% infants. Early clinical improvement was observed in all cases that underwent surgery and most of them had a low birth weight (<1500 g) and an early gestational age (<32 weeks). None of them died due to operation. CONCLUSION: The incidence of symptomatic PDA is high in preterm infants. Treatment with indomethacine improves ductal closure and is associated with few reversible adverse effects. In the other hand, early clinical improvement and high success rate were achieved after surgery. If indomethacine fails to achieve ductal closure, decision of surgery must be made immediately.     

Pulsed Doppler and bidimensional echocardiography in patent ductus arteriosus

The classical form of patent ductus arteriosus (PDA) does not usually pose any difficulty in diagnosing. When the auscultatory signs are atypical, for example in the newborn or in cases with pulmonary hypertension, pulsed Doppler echocardiography may be a useful diagnostic aid. This study reports the results of pulsed Doppler examination in PDA. Twenty-four children with a suspected PDA underwent pulsed Doppler examination during 2D echocardiography. This population was divided into 2 groups; Group I: children who underwent catheterisation, and group II: in which catheterisation was not performed. The mean age in Group I was 7 years compared to 50 days in Group II, which mainly comprised newborn and premature babies. Direct visualisation of PDA by 2D echo was attempted in all cases. The search for a PDA by pulsed Doppler was made by positioning the sample volume at the bifurcation of the main pulmonary artery. PDA is associated with turbulent systolo-diastolic flow away from the transducer. Suprasternal and subcostal views were also used. In Group I (13 cases) PDA was directly visualised by 2D echo in 7 children (53 p. 100). By comparison, pulsed Doppler examination diagnosed all 13 cases of PDA; these results were confirmed at catheterisation or surgery. In Group II (11 cases) direct visualisation of PDA was successful in 6 cases (54 p. 100). Pulsed Doppler was non-specific, showing typical flow disturbances in 8 cases and systolic turbulence in 3 cases at the level of bifurcation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of patent ductus arteriosus on the heart in preterm infants

There continues to be controversy on the long‐term effects of a patent ductus arteriosus (PDA) and its management. However, the hemodynamic effects of a large PDA in a preterm infant are well known. This article aims to provide insight into the adaptive changes and remodeling effects of a PDA on the myocardium in preterm infants.     

Overview of transcatheter patent ductus arteriosus closure in preterm infants

Clinically significant patent ductus arteriosus (PDA) has been associated with significant morbidity in extremely low birth weight (ELBW) infants. Current management of ELBW infants with hemodynamically significant PDA includes supportive treatment, pharmacological therapy, and surgical ligation. All of these therapeutic options have their advantages and limitations. More recently, transcatheter PDA closure has been described as a viable option in this population. In this paper, we provide a comprehensive review of this emerging procedure.     

A comprehensive program for preterm infants with patent ductus arteriosus

Objectives: Patent ductus arteriosus (PDA) is a common finding in preterm infants. A hemodynamically significant PDA may require intervention for closure. This article aims to describe a transcatheter PDA closure (TCPC) program for preterm infants and the components of a comprehensive outpatient follow-up strategy.
Setting: A multidisciplinary team approach including neonatology, cardiology, anesthesiology, medical transport team, pulmonology, cardiac surgery, neurodevelopmental specialist, nutrition, speech therapy, social work, research collaborators, and other health care specialists is integral to the dedicated care and promotion of wellness of extremely low birth weight (ELBW) infants.
Patients: To date, we have performed TCPC on 134 ELBW infants weighing <2 kg at the time of the procedure, 54 of whom were <1 kg with the smallest weighing 640 g with a median gestation age of 25 weeks (range 23-27 weeks).
Interventions: A comprehensive follow-up strategy with the creation of the Memphis PDA Clinic was implemented.
Outcome measures: Respiratory support, tolerance of enteral feeds, growth, and neurodevelopmental progress are indicators of favorable outcomes.
Results: TCPC has benefited ELBW infants with faster weaning off the ventilator, increase in enteral feedings, and somatic growth with the overall shortening of the hospital length of stay. The Memphis PDA Clinic has ensured optimal postdischarge follow-up to improve long-term outcomes.
Conclusions: TCPC is a safe and effective alternative to manage ELBW infants with a hemodynamically significant PDA. Comprehensive follow-up after discharge provided in a multispecialty clinic developed specifically for this unique population has been successful in improving outcomes.     

Single-dose prophylactic ibuprofen therapy for patent ductus arteriosus in preterm infants

This study aimed to evaluate the short-term morbidities and efficacy of single-dose prophylactic intravenous ibuprofen for patent ductus arteriosus (PDA) on the first day of life in preterm infants.Data of 69 preterm infants with birth weight < 1250 g and gestational age < 30 weeks admitted to the neonatal intensive care unit were analyzed. Of these, 37 infants were assigned to the prophylactic treatment (PT) group and 32 were assigned to the nonprophylactic treatment (non-PT) group. Only the PT group administered intravenous ibuprofen (10 mg/kg) once within 6 hours after birth.Until postnatal day 7, ductal closure occurred in 11 (34.4%) infants in the non-PT group, and in 35 (94.6%) infants in the PT group, of which 30 (81.1%) infants had ductal closure on postnatal day 1. There were 2 (5.4%) infants in the PT group and 9 (28.1%) in the non-PT group who needed ibuprofen treatment due to moderate-to-large PDA after postnatal day 7. Preterm infants in the PT group were less likely to develop an intraventricular hemorrhage (≥grade 2) (adjusted odds ratio 0.007, 95% confidence interval 0.01–0.45), had a shorter duration of invasive ventilatory support and central venous catheter, and earlier postnatal age to achieve feeding of 50 and 100 mL/kg/day compared with those in the non-PT group.Single-dose prophylactic intravenous ibuprofen on the first day of life decreased the occurrence of a persistent PDA and intraventricular hemorrhage (≥grade 2), and reduced the duration of invasive ventilatory support, central venous catheter use, and hospital stay.     

Noninvasive assessment of indomethacin therapy in patent ductus arteriosus in preterm infants

We performed 138 serial two-dimensional (2-D), M-mode, and Doppler echocardiographic studies to assess the efficacy of intravenous indomethacin (INDO) therapy for patent ductus arteriosus (PDA) in 41 preterm infants. Nine infants expired without sufficient echo data to warrant inclusion in the study. Of the remaining 32 infants, 12 (Group 1) required ligation despite INDO therapy, 18 (Group 2) responded to INDO or spontaneously closed their PDAs, and 2 were transferred to other hospitals with their PDAs still open and were lost to follow-up. The presence of PDA was verified by 2-D echo visualization of the ductus (high parasternal short-axis views) and Doppler demonstration of high velocity ductal flow toward the main pulmonary artery. The ratio of PDA lumen to aortic root inner diameter (Ao) was measured as well. Indication for surgical ligation was failure of the PDA to close after 3 or more courses of INDO. In Group 1, the PDA/Ao ratio was 0.45 +/- 0.10 standard error of the mean (SEM) pre-INDO, and 0.40 +/- 0.12 SEM post-INDO (immediately before ligation). In Group 2, the PDA/Ao ratio was 0.42 +/- 0.11 SEM pre-INDO, and 0.19 +/- 0.14 SEM at the end of INDO course (p less than 0.001), with 12 infants showing no ductal flow by Doppler. Follow-up six months after INDO therapy has shown no residual murmurs or other evidence of PDA in any INDO-closed infant. Five of the 18 infants have undergone repeated echocardiographic studies, all of which were negative for PDA patency or flow.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection and quantitation of constriction of the fetal ductus arteriosus by Doppler echocardiography

Pulmonary hypertension may occur in the fetus in the presence of constriction of the ductus arteriosus. The feasibility of detection and quantitation of fetal ductal constriction by Doppler echocardiography was assessed in an animal preparation in which ductal constriction was created in the fetal lamb with a variable ligature causing varying degrees of fetal pulmonary hypertension (fetal pulmonary arterial systolic pressure 57 to 97 mm Hg and ductal gradient 9 to 42 mm Hg). Comparison of blinded, continuous-wave peak Doppler velocity (V) measurements of the ductal gradient with the modified Bernoulli assumption (gradient = 4V2) compared well with direct catheter measurements of instantaneous peak systolic gradient (r = .99, catheter = 0.95 X Doppler + 0.6), peak-to-peak gradient (r = .97), and mid-diastolic gradient (r = .85). Ductal constriction was characterized by an increase in the peak systolic and diastolic velocities. The normal human fetal ductus arteriosus blood flow velocity pattern was assessed by pulsed Doppler techniques in 25 normal human fetuses after 20 weeks gestation. The peak systolic flow velocity in the ductus arteriosus measured by image-directed pulsed Doppler echocardiography ranged from 50 to 141 cm/sec (mean 80 cm/sec) and increased with gestational age (r = .50). Diastolic velocity in the ductus arteriosus was consistently directed toward the descending aorta and ranged from 6 to 30 cm/sec. The ductal systolic velocities were the highest blood flow velocities in the fetal cardiovascular system. Application of these techniques to fetuses whose mothers were receiving indomethacin for treatment of premature labor at 30 to 31 weeks gestation confirmed this method to be sensitive for detection of fetal ductal constriction, which developed in three fetuses.(ABSTRACT TRUNCATED AT 250 WORDS)     

Doppler echocardiography of fetal ductus arteriosus constriction versus increased right ventricular output

A prospective longitudinal study from 121 examinations of 41 normal pregnant women showed that fetal ductal flow velocities increased with gestational age. These normal data were compared with data in three groups of fetuses with altered ductal flow velocities: 22 fetuses (mean gestational age 31.3 weeks) had ductal constriction due to maternal indomethacin treatment; 10 fetuses (mean gestational age 27.9 weeks) had been exposed to terbutaline, a positive inotropic agent and 14 fetuses (mean gestational age 33.3 weeks) had hypoplastic left heart syndrome. In normal fetuses maximal systolic, mean and end-diastolic ductal flow velocities increased linearly (p less than 0.0001). The pulsatility index did not change (mean +/- 2 SD: 2.46 +/- 0.52). Fetuses with ductal constriction had higher maximal, mean and end-diastolic flow velocities and a significantly lower pulsatility index than did normal fetuses (1.25 +/- 0.76; p less than 0.0005). Six of 10 fetuses of the terbutaline group and 8 of 14 fetuses with hypoplastic left heart syndrome had increased maximal flow velocity, but normal or only mildly elevated mean flow velocity. The pulsatility index in fetuses during terbutaline therapy and with hypoplastic left heart syndrome was significantly higher than in normal fetuses (3.11 +/- 0.46 and 3.09 +/- 0.7, respectively, vs. 2.46 +/- 0.52; p less than 0.0005). Fetal ductal waveform analysis was necessary to distinguish fetal ductal constriction from increased right ventricular output. These measurements may be helpful in the diagnosis of left-sided outflow obstruction and assessment of fetal hemodynamic data.     

Patent ductus arteriosus in premature infants

An analysis of the course and complications in the ligation of patent ductus arteriosus (PDA) in 30 very low birth-weight preterm neonates was carried out. The mean gestational stage at birth was 26.97 weeks, and median weight was 811 gm. Attempted closures of the ductus with indomethacin in 19 infants failed, although there was temporary closure in nine. Congestive heart failure was present in 29 and respiratory distress syndrome in 22 patients. Endotracheal intubation with ventilation assistance was necessary in the entire series. The mean age at operation was 13.5 days, and ductal ligation was performed in the intensive care unit under local anesthesia, supplemented with pancuronium and pethidine. There were no intraoperative deaths, but five infants died during their hospitalization from unremittent respiratory distress syndrome. There were seven additional late deaths. Eighteen survivors were followed for a mean of 26.5 months. Early ligation of PDA in very low birth-weight prematures improved the cardiorespiratory status, and long-term follow-up revealed good clinical progress in two-thirds of the surviving group.     

Noninvasive detection of pulmonary hypertension in patent ductus arteriosus by pulsed Doppler echocardiography.

Twenty-five patients with proven patent ductus arteriosus were examined by pulsed Doppler echocardiography (PDE) before invasive assessment. Ten patients had normal pulmonary artery pressures, and by PDE, pandiastolic ductal flow. Fifteen patients had elevation of mean pulmonary artery pressure, and by PDE, all had abbreviations of diastolic ductal flow. PDE correctly distinguished between patients with normal pressure and those with evidence of pulmonary hypertension; the ECG did not allow such differentiation. Detection by PDE of pulmonary hypertension complicating patent ductus arteriosus appears to be clinically useful.