Short- and medium-term outcomes for patent ductus arteriosus stenting in neonates ≤2.5 kg with duct-dependent pulmonary circulation.

BACKGROUND: Morbidity with surgical systemic-to-pulmonary artery shunting (SPS) in infants ≤2.5 kg has remained high. Patent ductus arteriosus (PDA) stenting may be a valid alternative. The objective of this study is to evaluate outcomes following PDA stenting in patients ≤2.5 kg from four large tertiary centers. METHODS: Retrospective review of all neonates ≤2.5 kg with duct-dependent pulmonary circulation who underwent PDA stenting. Procedural details, pulmonary arterial growth, reinterventions, surgery type, and outcomes were assessed. RESULTS: PDA stents were implanted in 37 of 38 patients attempted (18 female) at a median procedural weight of 2.2 kg (interquartile range [IQR], 2-2.4 kg). Seven patients (18%) had a genetic abnormality and 16 (42%) had associated comorbidities. The median intensive care unit stay was 4 days (IQR, 2-6.75 days), and the median hospital stay was 20 days (IQR, 16-57.25). One patient required a rescue shunt procedure, with three others requiring early SPS (<30 days postprocedure). Twenty patients (54%) required reintervention with either balloon angioplasty, restenting, or both. At 6-month follow-up, right pulmonary artery growth (median z-score -1.16 to 0.01, p = 0.05) was greater than the left pulmonary artery (median z-score -0.9 to -0.64, p = 0.35). Serious adverse effects (SAEs) were seen in 18% (N = 7) of our cohort. One patient developed an SAE during planned reintervention There were no intraprocedural deaths, with one early procedure-related mortality, and three interstage mortalities not directly related to PDA stenting. CONCLUSIONS: PDA stenting in infants ≤2.5 kg is feasible and effective, promoting pulmonary artery growth. Reintervention rates are relatively high, though many are planned to allow for optimal growth before a definitive operation.

A Pilot Randomized Controlled Trial of Early Targeted Patent Ductus Arteriosus Treatment Using a Risk Based Severity Score (The PDA RCT).

OBJECTIVES: To evaluate the feasibility of recruiting preterm infants to a randomized controlled trial of patent ductus arteriosus (PDA) treatment based on a PDA severity score (PDAsc) and to characterize challenges in obtaining consent, compliance with the protocol, and PDA closure rates. STUDY DESIGN: This single-center, randomized control pilot study of 60 infants <29 weeks of gestation with a high PDAsc (≥5.0) at 36-48 hours of age receiving either ibuprofen or placebo intravenously. The study protocol did not allow for additional PDA therapy within the first 2 weeks. We reported the rate of consent, open label treatment, and PDA closure rates. The primary outcome was chronic lung disease or death. RESULTS: We approached 83 families for enrollment with 73 (88%) providing consent; 13 infants had a PDAsc of <5; of the remaining infants, 30 were assigned ibuprofen and 30 received placebo. Eight infants received open label treatment in the first 2 weeks (12%). The overall PDA closure rate after treatment was 57% in the intervention group and 17% in the control group (P < .01). There was no difference in the primary clinical outcome (OR, 0.8; 95% CI, 0.3-2.1). CONCLUSIONS: Using a PDAsc for infant recruitment to a PDA treatment randomized controlled trial is feasible. There is a high rate of consent and relatively low rate of open-label PDA treatment. The overall PDA closure rate in the intervention arm was low placing the emphasis on devising more effective PDA closure strategies in future randomized controlled trials. TRIAL REGISTRATION: ISRCTN (13281214) and European Union Drug Regulating Authorities Clinical Trials Database (2015-004526-33).

Transcarotid Approach to Ventricular Septal Defect Closure in Small Infants.

Perimembranous ventricular septal defect closure in small infants has traditionally been a surgically treated defect, although alternative hybrid strategies are emerging. We aim to describe a novel approach to retrograde device closure of clinically relevant perimembranous ventricular septal defects in small infants via carotid cutdown. A retrospective review of all patients managed with attempted carotid cutdown for device closure of a perimembranous ventricular septal defect was recorded at a single tertiary cardiac centre. We summarized data on successful device deployment, conversion to open repair, complications, and length of stay. Eighteen infants with median (IQR) age of 7 months (5-9 months) and weight of 7.1 kg (6.5-7.8 kg) with clinically relevant PMVSD underwent attempted retrograde closure via carotid cutdown. Median (IQR) defect size was 8 mm (7-9 mm). Successful device deployment without significant aortic or tricuspid valve interference occurred in 15 (83%) patients. Three patients were converted to open repair, one following damage to the tricuspid valve apparatus. Median (IQR) hospital stay was 1 day (1-3 days). There were no complications related to carotid cutdown. Retrograde device closure of hemodynamically significant PMVSD is feasible and effective in small infants. Decision to convert to surgical repair should be made early if suboptimal device placement occurs. Carotid evaluation should be performed to rule out any access-related complications.

Impaired Right Ventricular Performance Is Associated with Adverse Outcome after Hypoxic Ischemic Encephalopathy.

Rationale: Asphyxiated neonates with hypoxic ischemic encephalopathy (HIE) are at risk of myocardial dysfunction; however, echocardiography studies are limited and little is known about the relationship between hemodynamics and brain injury.Objectives: To analyze the association between severity of myocardial dysfunction and adverse outcome as defined by the composite of death and/or abnormal magnetic resonance imaging.Methods: Neonates with HIE undergoing therapeutic hypothermia were enrolled. Participants underwent echocardiography at 24 hours, 72 hours (before rewarming), and 96 hours (after rewarming). Cerebral hemodynamics were monitored by near-infrared spectroscopy and middle cerebral artery Doppler.Measurements and Main Results: Fifty-three patients with a mean gestation and birthweight of 38.8 ± 2.0 weeks and 3.33 ± 0.6 kg, respectively, were recruited. Thirteen patients (25%) had mild encephalopathy, 27 (50%) had moderate encephalopathy, and 13 (25%) had severe encephalopathy. Eighteen patients (34%) had an adverse outcome. Severity of cardiovascular illness (P < 0.001) and severity of neurologic insult (P = 0.02) were higher in neonates with adverse outcome. Right ventricle (RV) systolic performance at 24 hours was substantially lower than published normative data in all groups. At 24 hours, lower tricuspid annular plane systolic excursion (P = 0.004) and RV fractional area change (P < 0.001), but not pulmonary hypertension, were independently associated with adverse outcome on logistic regression. High brain regional oxygen saturation (P = 0.007) and low middle cerebral artery resistive index (P = 0.04) were associated with RV dysfunction on post hoc analysis.Conclusions: RV dysfunction is associated with the risk of adverse outcome in asphyxiated patients with HIE undergoing hypothermia. Echocardiography may be a valuable diagnostic and prognostic tool in this vulnerable population.

Cardiac strangulation causing refractory cardiac arrest during elective pacemaker revision: a cautionary tale.

We describe a previously asymptomatic 7-year-old girl with a sudden cardiac arrest during elective pacemaker revision. Later imaging identified epicardial pacemaker lead strangulation of the left anterior descending and left circumflex coronary arteries. Anaesthetic induction led to a reduction in myocardial perfusion, precipitating the arrest. Extreme care should be taken during anaesthesia if cardiac strangulation is suspected.

Percutaneous axillary artery approach for ductal stenting in critical right ventricular outflow tract lesions in the neonatal period.

OBJECTIVES: We aimed to assess the experience using a percutaneous axillary artery approach for insertion of arterial ductal stents in patients with critical right ventricular outflow tract lesions at two tertiary pediatric cardiology centers. BACKGROUND: Patent ductus arteriosus stenting is an accepted palliative alternative to BT shunts for neonates with critical right heart lesions. Access to tortuous ductus' may be challenging via the femoral artery, whereas the carotid artery presents a low risk of stroke. Recently, the axillary artery has been utilized for access in these patients. METHODS: We performed a retrospective review of neonates who underwent stent placement or angioplasty using percutaneous axillary artery approach at two tertiary care centers from October 2016 to November 2018. Medical records were reviewed to ascertain demographic, clinical, and outcome data. RESULTS: Axillary artery access was performed in 20 patients (16 primary ductal stents and 4 re-interventions) at a median (IQR) procedural weight of 3.4 (3-3.9) kg. Median (IQR) procedural time was 110 (75-150) min. The median (IQR) ICU stay and intubation times were 14 (0-94) hr and 5 (0-40) hr, respectively. There were three access-related vascular complications which were managed conservatively with no long-term effects. Two patients subsequently died due to non-procedure related causes. CONCLUSIONS: Ductal stenting via a percutaneous axillary artery approach is a viable option in neonates with critical right ventricular outflow tract lesions. This approach provides an additional access site for PDA stenting which may be utilized in patients with vertical duct morphology.

Retroaortic innominate vein in a patient with transposition of the great arteries: the surgical implications.

We describe the case of a newborn infant with transposition of the great vessels and a retroaortic innominate vein. This is a previously undescribed association. The decision was made to incorporate the retroaortic innominate vein into the Lecompte procedure at the time of surgery to avoid the risk of superior caval vein syndrome.

Infants Born with Down Syndrome: Burden of Disease in the Early Neonatal Period.

OBJECTIVE: To evaluate the incidence of direct admission of infants with Down syndrome to the postnatal ward (well newborn nursery) vs the neonatal intensive care unit (NICU), and to describe the incidence of congenital heart disease (CHD) and pulmonary hypertension (PH). STUDY DESIGN: This retrospective cohort study of Down syndrome used the maternal/infant database (2011-2016) at the Rotunda Hospital in Dublin, Ireland. Admission location, early neonatal morbidities, outcomes, and duration of stay were evaluated and regression analyses were conducted to identify risk factors associated with morbidity and mortality. RESULTS: Of the 121 infants with Down syndrome, 54 (45%) were initially admitted to the postnatal ward, but 38 (70%) were later admitted to the NICU. Low oxygen saturation profile was the most common cause for the initial and subsequent admission to the NICU. Sixty-six percent of the infants (80/121) had CHD, 34% (41/121) had PH, and 6% died. Risk factors independently associated with primary NICU admission included antenatal diagnosis of Down syndrome, presence of CHD, PH, and the need for ventilation. CONCLUSIONS: Infants with Down syndrome initially admitted to the postnatal ward have a high likelihood of requiring NICU admission. Overall, high rates of neonatal morbidity were noted, including rates of PH that were higher than previously reported. Proper screening of all infants with Down syndrome for CHD and PH is recommended to facilitate timely diagnoses and potentially shorten the duration of the hospital stay.

Incidental Findings on Routine Targeted Neonatal Echocardiography Performed in Preterm Neonates Younger Than 29 Weeks' Gestation.

OBJECTIVES: The aim of this study was to quantify the rate of incidental findings identified on elective research echocardiography performed on neonates younger than 29 weeks' gestation. METHODS: We conducted a retrospective study of echocardiographic examinations performed within the first 24 hours of age on neonates younger than 29 weeks' gestation over a 3-year period for research purposes. Incidental echocardiographic findings and pertinent clinical data were recorded. RESULTS: Echocardiographic examinations performed on 145 neonates were retrospectively reviewed. Forty-three neonates (30%) had a total of 54 unexpected findings (37%). Most comprised malpositioned umbilical venous catheters, where the tip was located in the left atrium. The remainder of the conditions identified included unsuspected congenital heart disease, liver hematomas, and unexpected pulmonary hypertension. CONCLUSIONS: There is a high rate of incidental findings identified on screening echocardiograms. Routine targeted neonatal echocardiographic screening of preterm neonates may be warranted to identify the considerable likelihood of asymptomatic findings.

Ruptured Sinus of Valsalva Aneurysm and Gerbode Defects: Patient and Procedural Selection: the Key to Optimising Outcomes.

PURPOSE OF REVIEW: In this review, we reflect on the historical background, clinical features and imaging techniques used to assess Gerbode defects and sinus of Valsalva aneurysms. We aim to review the evolution of treatment strategies and the progression towards less invasive management for these conditions. RECENT FINDINGS: While transthoracic echocardiography is often diagnostic, transesophageal echocardiography (2D and 3D) has improved our understanding of these defects and allowed us to more accurately define their anatomy. Cardiac MRI provides improved assessment of the physiological impact of defects by quantifying shunt volume. Transcatheter techniques are currently vying with surgery as the mainstay of treatment. New insights are being discovered regarding diagnostic modalities and treatment pathways. Defining criteria for patient selection for catheter or surgical therapy is essential when deciding on the optimum intervention for the individual patient.

Prevalence of Subclinical Enteric Alpha-1-Antitrypsin Loss in Children with Univentricular Circulation Following Total Cavopulmonary Connection.

Protein-Losing Enteropathy post Fontan palliation is associated with significant morbidity and mortality. To date, very little research has been carried out to improve early identification of enteric protein loss in these patients. We hypothesise that subclinical enteric protein loss may occur in patients post Fontan surgery. A cross-sectional study was performed on 43 patients post Fontan surgery. We collected specimens of stool and blood from patients with no symptoms of protein-losing enteropathy post Fontan. Stool samples were assessed for alpha one antitrypsin. The stool samples of two patients were discarded, leaving 41 stool samples. Blood samples were also collected to review albumin, C-reactive protein, liver and renal function. Twenty-eight (65%) of those enrolled were male. The median (IQR) age between Fontan and collection of study specimens was 3.5 (2-7) years. Two (5%) patients had elevated levels of alpha-1-antitrypsin. There was no correlation between blood biochemistry and elevated stool alpha-1-antitrypsin. Subclinical protein loss is rare in asymptomatic children after Fontan procedure with only 5% of patients having elevated stool alpha-1-antitrypsin but no other symptoms. These findings may relate to our small cohort size and the time to testing post cardiac surgery. Future longitudinal follow-up studies should assess the ability of alpha-1-antitrypsin to provide earlier detection of protein-losing enteropathy in asymptomatic patients post Fontan. Given the serious prognosis of protein-losing enteropathy in this patient group, further work is warranted.

The Effect of a Significant Patent Ductus Arteriosus on Doppler Flow Patterns of Preductal Vessels: An Assessment of the Brachiocephalic Artery.

Systemic hypoperfusion secondary to a patent ductus arteriosus (PDA) is thought to only affect post-ductal vessels. In a prospective observational study of 51 preterm infants, we demonstrated that a persistent PDA by day 5-7 is associated with reversed diastolic flow in the brachiocephalic artery when compared with those without a PDA.

Noninvasive continuous cardiac output and cerebral perfusion monitoring in term infants with neonatal encephalopathy: assessment of feasibility and reliability.

BackgroundNoninvasive hemodynamic monitoring of infants with neonatal encephalopathy (NE) undergoing therapeutic hypothermia (TH) would be a potentially useful clinical tool. We aimed to assess the feasibility and reliability of noninvasive cardiac output monitoring (NICOM) and near-infrared spectroscopy (NIRS) in this cohort.MethodsNICOM and NIRS were commenced to measure cardiac output (CO), systemic vascular resistance (SVR), blood pressure (BP), and cerebral regional oxygen saturations (SctO2) during TH and rewarming. NICOM measures of CO were also compared with simultaneous echocardiography-derived CO (echo-CO).ResultsTwenty infants with a median gestation of 40 weeks were enrolled. There was a strong correlation between NICOM- and echo-CO (r2=0.79, P<0.001). NICOM-CO was systematically lower than echo-CO with a bias of 27% (limits of agreement 3-51%). NICOM illustrated lower CO during TH, which increased during rewarming. SctO2 increased over the first 30 h of TH and stayed high for the remainder of the study. There was a rise in SVR over the first 30 h of TH and a decrease during rewarming (all P<0.05).ConclusionsNoninvasive hemodynamic assessment of infants with NE is feasible and illustrates potentially important changes. Larger studies are needed to assess the clinical applicability of those methods in this cohort.

Left ventricular rotational mechanics in infants with hypoxic ischemic encephalopathy and preterm infants at 36 weeks postmenstrual age: A comparison with healthy term controls.

BACKGROUND AND AIMS: There is a paucity of data on left ventricle (LV) rotational physiology in neonates. We aimed to assess rotational mechanics in infants with hypoxic ischemic encephalopathy (HIE) and premature infants (<32 weeks) at 36 weeks postmenstrual age (PMA) (preterm group) and compare them with healthy term controls (term controls). We also compared the parameters in preterm infants with and without chronic lung disease (CLD). METHODS: Echocardiography was performed within 48 hours of birth or at 36 weeks PMA. LV basal and apical rotation, twist (and torsion=twist/LV length), twist rate (LVTR), and untwist rate (LVUTR) were measured. One-way ANOVA was used to compare values. RESULTS: There was no difference in gestation (40.0 [39.1-40.3] vs 39.9 [39.0-40.9], P>.05) or birthweight (3.7 [3.4-4.1] vs 3.5 [3.2-3.9], P>.05) between the HIE group (n=16) and term controls (n=30). The preterm group (n=35) had a gestation and weight of 36.0 [34.6-36.3] weeks and 2.3 [2.0-2.4] kg. The HIE group had lower twist, torsion, LVTR, and LVUTR than the other two groups. The preterm group had a more negative (clockwise) basal rotation while the term group had a more positive (counterclockwise) apical rotation. Preterm infants with CLD had higher apical rotation, twist, and torsion when compared to infants without CLD. CONCLUSION: Infants with HIE have reduced rotational mechanics. Preterm infants at 36 weeks PMA have comparable measurements of twist to term infants. This is achieved by predominant basal rather than apical rotation. Infants with CLD have increased apical rotation.

Cased-based education rounds-the eternal heart of an international training program.

Case-based teaching or "Morning Rounds" have been used in medical education for more than a century and remain a cornerstone for teaching in many training programs. Our Pediatric Critical Care Medicine (PCCM) program was established forty years ago and has retained this form of teaching since its inception. Case-based rounds have consistently had the highest evaluation of all curricula in our program. Here we review the history of how these rounds were introduced in medical education, provide data from the learners' evaluation of these case-based rounds, and discuss the strengths and potential drawbacks of this form of teaching from an educational theories perspective with the hope that they can be used by other Pediatric Critical Care training programs.

Patent ductus arteriosus shunt elimination results in a reduction in adverse outcomes: a post hoc analysis of the PDA RCT cohort.

OBJECTIVE: A post hoc appraisal of the PDA RCT to assess the relationship between early patent ductus arteriosus (PDA) shunt elimination and chronic lung disease or death (CLD/Death). STUDY DESIGN: Infants <29 weeks were divided into four groups: intervention arm in whom PDA closure was achieved (n = 17); intervention arm in whom PDA closure was not achieved (n = 13); placebo arm (n = 30); low risk infants (n = 13). The main outcome measure was CLD/Death. RESULTS: The rates of CLD/Death were lower in the Intervention Success Group (29%) when compared to the Intervention Failure Group (85%) or the Placebo Group (60%, all p < 0.05). There was no difference in CLD/Death between the Intervention Success and Low Risk Groups (8%, p > 0.05). A persistent PDA beyond Day 8 was associated with CLD/Death (aOR 6.5 [1.7-25.5]). CONCLUSIONS: Early shunt elimination in preterm infants with a PDA may reduce respiratory morbidity when compared to infants with prolonged shunt exposure.

Procedural technique for hybrid pulmonary valve replacement in infants and small children.

OBJECTIVES: Hybrid approach to pulmonary valve replacement (PVR) in the paediatric population has been reported, although data in infants and small children are limited. Several strategies are now possible. The aim of this study is to review our hybrid PVR strategy in a complex patient cohort, outlining a variety of approaches employed in our centre. METHODS: We performed a retrospective review of infants and small children who underwent hybrid PVR between May 2017 and April 2019 in a single tertiary cardiology centre. Medical records were reviewed to ascertain demographic, clinical and outcome data. RESULTS: Ten patients with a median (interquartile range) age of 1.5 years (1.1-1.9) and weight of 8.8 kg (8-10.6) were managed with hybrid pulmonary valve insertion. Eight patients had perventricular approach (4 sternotomy and 4 subxiphoid) and 2 patients had surgically sutured valve. Six patients underwent cardiopulmonary bypass for associated lesions. Three had insertion of the valve into conduits and 7 were deployed into native right ventricular outflow tracts. The pulmonary valve was successfully inserted in all 10 patients with no mortality. Postprocedural complications included paravalvar leak in 2 patients, suspected endocarditis in 1 patient who developed early valve regurgitation and wound infection in 1 patient. CONCLUSIONS: Several approaches to hybrid PVR may be employed in small children with a high success rate. Follow-up studies are required to evaluate longer term durability of these approaches compared to standard surgical replacement.

Early targeted patent ductus arteriosus treatment in premature neonates using a risk based severity score: study protocol for a randomised controlled trial (PDA RCT).

A patent ductus arteriosus (PDA) in preterm infants is associated with increased ventilator dependence and chronic lung disease, necrotizing enterocolitis, intraventricular haemorrhage, and poor neurodevelopmental outcome. Randomised controlled trials of early PDA treatment have not established a drop in the aforementioned morbidities. Those trials did not physiologically categorise PDA severity. Incorporating the specific physiological features of a haemodynamic significant PDA may evolve our understanding of this phenomenon, allowing accurate triaging using echocardiography and targeted treatment.  Our group has recently demonstrated that a PDA severity score (PDAsc) derived at 36-48 hours of age can accurately predict the later occurrence of chronic lung disease or death (CLD/Death). Using echocardiography, we assessed PDA characteristics, as well as left ventricular diastolic function and markers of pulmonary overcirculation, and from this formulated a PDAsc. Gestation was also incorporated into the score. We hypothesise that in preterm infants at high risk of developing CLD/Death based on a PDAsc, early treatment with Ibuprofen compared with placebo will result in a reduction in CLD/Death. This is a single centre double-blind two arm randomised controlled trial conducted in the neonatal intensive care unit in the Rotunda Hospital, Dublin. Echocardiogram is carried out in the first 36-48 hours of life to identify preterm infants with a PDAsc ≥ 5.0 and these infants are randomised to Ibuprofen or placebo. Primary outcomes are assessed at 36 weeks post menstrual age. This pilot study's purpose is to assess the feasibility of performing the trial and to obtain preliminary data to calculate a sample size for a definitive multi-centre trial of early PDA treatment using a PDAsc. We aim to recruit a total of 60 infants with a high risk PDA over three years. Trial Registration: ISRCTN ISRCTN13281214 (26/07/2016) and the European Union Drug Regulating Authorities Clinical Trials Database 2015-004526-33 (03/12/2015).

Left ventricular diastolic function influences right ventricular - Pulmonary vascular coupling in premature infants.

INTRODUCTION: Reduced left ventricular (LV) diastolic function can exert significant load to the right ventricle (RV) that can affect RV-pulmonary vasculature (PV) coupling. RV-PV can be assessed with the RV length-force relationship (tricuspid annular plane systolic excursion [TAPSE] to pulmonary artery acceleration time [PAAT] ratio). We aimed to determine the association between LV diastolic function measured using tissue Doppler imaging (TDI) and TAPSE/PAAT. METHODS: A study of premature infants <29 weeks gestation. TAPSE/PAAT, LV e' and a' waves were measured on Day 1 following birth. Correlation between diastolic indices and TAPSE/PAAT was performed. The independent effect of LV diastolic function and TAPSE/PAAT was assessed using linear regression. RESULTS: One hundred and sixty-two infants with a mean ±â€¯SD gestation & birthweight of 26.6 ±â€¯1.5 weeks & 938 ±â€¯241 g. There was a significant positive correlation between LV e' (r = 0.44, p < 0.01)/LV a' (r = 0.44, p < 0.01) and TAPSE/PAAT. This relationship remained significant when adjusting for important confounders (all p < 0.01). Infants with LV a' values in the lowest quartile had lower TAPSE values (4.2 ±â€¯1.2 vs. 5.1 ±â€¯1.1 mm, p < 0.01) without a difference in PAAT (41 ±â€¯8 vs. 41 ±â€¯10 ms, p = 0.97). CONCLUSIONS: We observed a direct correlation between LV diastolic function and RV-PV coupling in the first day of age, highlighting the importance ventricular interdependence in premature infants. TAPSE/PAAT, as the index of the RV-PV interaction may be further explored for its potential to assess RV reserve under stress with preterm infants in health and disease.

Cardiac mechanics in infants with Down syndrome in the early neonatal period.

OBJECTIVE: The objective of this study is to test whether myocardial performance is impaired over the first week of age in infants with Down syndrome (DS) without congenital heart disease (CHD). STUDY DESIGN: A prospective cohort study of 20 infants with DS without CHD and 17 healthy term infants comparing echocardiographic measures of left (LV) and right (RV) ventricular function and pulmonary hypertension (PH) on days 1, 2, and 5-7. RESULTS: Indices of PH were higher in the DS group over the study period. Infants with DS had larger RV and smaller LV dimensions. Fractional area change and RV longitudinal strain values were lower in the DS group. LV shear strain values were lower in infants with DS driven by a lack of basal rotation. CONCLUSION: Infants with DS without CHD and echocardiographic evidence of PH during the early neonatal period demonstrate reduced RV systolic function with impaired LV rotational mechanics, reflective of the ventricular interdependence.