Evolving Role of Three-Dimensional Echocardiography for Right Ventricular Volume Analysis in Pediatric Heart Disease: Literature Review and Clinical Applications

Accurate knowledge of right ventricular (RV) volumes and ejection fraction is fundamental to providing optimal care for pediatric patients with congenital and acquired heart disease, as well as pulmonary hypertension. Traditionally, these volumes have been measured using cardiac magnetic resonance because of its accuracy, reproducibility, and freedom from geometric assumptions. More recently, an increasing number of studies have described the measurement of RV volumes using three-dimensional (3D) echocardiography. In addition, volumes by 3D echocardiography have also been used for outcome research studies in congenital heart surgery. Importantly, 3D echocardiographic acquisitions can be obtained over a small number of cardiac cycles, do not require general anesthesia, and are less costly than CMR. The ease and safety of the 3D echocardiographic acquisitions allow serial studies in the same patient. Moreover, the studies can be performed in various locations, including the intensive care unit, catheterization laboratory, and general clinic. Because of these advantages, 3D echocardiography is ideal for serial evaluation of the same patient. Despite these potential advantages, 3D echocardiography has not become a standard practice in children with congenital and acquired heart conditions. In this report, the authors review the literature on the feasibility, reproducibility, and accuracy of 3D echocardiography in pediatric patients. In addition, the authors investigate the advantages and limitations of 3D echocardiography in RV quantification and offer a pathway for its potential to become a standard practice in the assessment, planning, and follow-up of congenital and acquired heart disease.

Establishing a neonatology consultation program: extending care beyond the neonatal intensive care unit

Neonates can be cared for in neonatal, pediatric, or cardiac intensive care units, and general and subspecialty pediatric units. Disposition is based on phase of care, gestational and postnatal age, birth weight, specific cardiac or surgical diagnoses, and co-existing medical morbidities. In addition, neonates may transfer between the neonatal intensive care unit (NICU) and other units several times throughout their hospitalization. As such, care for high-risk infants with ongoing neonatal morbidities (often related to prematurity or congenital anomalies) is provided in units with varying neonatal expertise. In this perspective, we provide a framework for the design and implementation of a neonatology consultation service for infants cared for in clinical units outside the NICU. We describe the core principles of effective neonatology consultation and focus on understanding hospital/unit workflow, team composition, patient selection, billing and compliance, and offer suggestions for research initiatives and educational opportunities.

Arch watch: current approaches and opportunities for improvement

Coarctation of the aorta (CoA) is a ductus arteriosus (DA)-dependent form of congenital heart disease (CHD) characterized by narrowing in the region of the aortic isthmus. CoA is a challenging diagnosis to make prenatally and is the critical cardiac lesion most likely to go undetected on the pulse oximetry-based newborn critical CHD screen. When undetected CoA causes obstruction to blood flow, life-threatening cardiovascular collapse may result, with a high burden of morbidity and mortality. Hemodynamic monitoring practices during DA closure (known as an "arch watch") vary across institutions and existing tools are often insensitive to developing arch obstruction. Novel measures of tissue oxygenation and oxygen deprivation may improve sensitivity and specificity for identifying evolving hemodynamic compromise in the newborn with CoA. We explore the benefits and limitations of existing and new tools to monitor the physiological changes of the aorta as the DA closes in infants at risk of CoA.

Asphyxia, Therapeutic Hypothermia, and Pulmonary Hypertension

Neonates with a perinatal hypoxic insult and subsequent neonatal encephalopathy are at risk of acute pulmonary hypertension (aPH) in the transitional period. The phenotypic contributors to aPH following perinatal asphyxia include a combination of hypoxic vasoconstriction of the pulmonary vascular bed, right heart dysfunction, and left heart dysfunction. Therapeutic hypothermia is the standard of care for neonates with moderate-to-severe hypoxic ischemic encephalopathy. This review summarizes the underlying risk factors, causes of aPH in neonates with perinatal asphyxia, discusses the unique phenotypical contributors to disease, and explores the impact of the initial insult and subsequent therapeutic hypothermia on aPH.

Guidelines and Recommendations for Targeted Neonatal Echocardiography and Cardiac Point-of-Care Ultrasound in the Neonatal Intensive Care Unit: An Update from the American Society of Echocardiography

Targeted neonatal echocardiography (TNE) involves the use of comprehensive echocardiography to appraise cardiovascular physiology and neonatal hemodynamics to enhance diagnostic and therapeutic precision in the neonatal intensive care unit. Since the last publication of guidelines for TNE in 2011, the field has matured through the development of formalized neonatal hemodynamics fellowships, clinical programs, and the expansion of scientific knowledge to further enhance clinical care. The most common indications for TNE include adjudication of hemodynamic significance of a patent ductus arteriosus, evaluation of acute and chronic pulmonary hypertension, evaluation of right and left ventricular systolic and/or diastolic function, and screening for pericardial effusions and/or malpositioned central catheters. Neonatal cardiac point-of-care ultrasound (cPOCUS) is a limited cardiovascular evaluation which may include line tip evaluation, identification of pericardial effusion and differentiation of hypovolemia from severe impairment in myocardial contractility in the hemodynamically unstable neonate. This document is the product of an American Society of Echocardiography task force composed of representatives from neonatology-hemodynamics, pediatric cardiology, pediatric cardiac sonography, and neonatology-cPOCUS. This document provides (1) guidance on the purpose and rationale for both TNE and cPOCUS, (2) an overview of the components of a standard TNE and cPOCUS evaluation, (3) disease and/or clinical scenario-based indications for TNE, (4) training and competency-based evaluative requirements for both TNE and cPOCUS, and (5) components of quality assurance. The writing group would like to acknowledge the contributions of Dr. Regan Giesinger who sadly passed during the final revisions phase of these guidelines. Her contributions to the field of neonatal hemodynamics were immense.

Risk Factors for Adverse Outcomes in Term Infants with CHD and Definitive Necrotising Enterocolitis

OBJECTIVES

To define the incidence of definitive necrotising enterocolitis in term infants with CHD and identify risk factors for morbidity/mortality.

METHODS

We performed a 20-year (2000-2020) single-institution retrospective cohort study of term infants with CHD admitted to the Boston Children's Hospital cardiac ICU with necrotising enterocolitis (Bell's stage ≥ II). The primary outcome was a composite of in-hospital mortality and post-necrotising enterocolitis morbidity (need for extracorporeal membrane oxygenation, multisystem organ failure based on the paediatric sequential organ failure assessment score, and/or need for acute gastrointestinal intervention). Predictors included patient characteristics, cardiac diagnosis/interventions, feeding regimen, and severity measures.

RESULTS

Of 3933 term infants with CHD, 2.1% (n = 82) developed necrotising enterocolitis, with 67% diagnosed post-cardiac intervention. Thirty (37%) met criteria for the primary outcome. In-hospital mortality occurred in 14 infants (17%), of which nine (11%) deaths were attributable to necrotising enterocolitis. Independent predictors of the primary outcome included moderate to severe systolic ventricular dysfunction (odds ratio 13.4,confidence intervals 1.13-159) and central line infections pre-necrotising enterocolitis diagnosis (odds ratio 17.7, confidence intervals 3.21-97.0) and mechanical ventilation post-necrotising enterocolitis diagnosis (odds ratio 13.5, confidence intervals 3.34-54.4). Single ventricle, ductal dependency, and feeding related factors were not independently associated with the primary outcome.

CONCLUSIONS

The incidence of necrotising enterocolitis was 2.1% in term infants with CHD. Adverse outcomes occurred in greater than 30% of patients. Presence of systolic dysfunction and central line infections prior to diagnosis and need for mechanical ventilation after diagnosis of necrotising enterocolitis can inform risk triage and prognostic counseling for families.

Preterm congenital heart disease and neurodevelopment: the importance of looking beyond the initial hospitalization

Congenital heart disease (CHD) and prematurity are leading causes of infant mortality in the United States. Infants with CHD born prematurely are often described as facing "double jeopardy" with vulnerability from their underlying heart disease and from organ immaturity. They endure additional complications of developing in the extrauterine environment while healing from interventions for heart disease. While morbidity and mortality for neonates with CHD have declined over the past decade, preterm neonates with CHD remain at higher risk for adverse outcomes. Less is known about their neurodevelopmental and functional outcomes. In this perspective paper, we review the prevalence of preterm birth among infants with CHD, highlight the medical complexity of these infants, and emphasize the importance of exploring outcomes beyond survival. We focus on current knowledge regarding overlaps in the mechanisms of neurodevelopmental impairment associated with CHD and prematurity and discuss future directions for improving neurodevelopmental outcomes.

Perioperative Care Models for Neonates With Congenital Heart Disease: Evolving Role of Neonatology Within the Cardiac Intensive Care Unit

A multidisciplinary team is needed to optimally care for infants with congenital heart disease (CHD). Different compositions of teams trained in cardiology, critical care, cardiothoracic surgery, anesthesia, and neonatology have been identified as being primarily responsible for perioperative care of this high-risk population in dedicated cardiac intensive care units (CICUs). Although the specific role of cardiac intensivists has become more well defined over the past two decades, the responsibilities of neonatologists remain highly variable in the CICU with neonatologists providing care along with a unique spectrum of primary, shared, or consultative care. The neonatologist can function as the primary physician and assume all or share responsibility with the cardiac intensivists for the management of infants with CHD. A neonatologist can provide care as a secondary consultant physician in a supportive role for the primary CICU team. Additionally, neonates with CHD can be mixed with older children in a CICU, cohorted in a dedicated space within the CICU or placed in a stand-alone infant CICU without older children. Although variations exist between centers on which model of care is deployed and the location within a CICU, characterization of current practice patterns represents the initial step required to determine optimal best practices to improve the quality of care for neonates with cardiac disease. In this manuscript, we present four models utilized in the United States in which the neonatologist provides neonatal-cardiac-focused care in a dedicated CICU. We also outline the different permutations of location where neonates can be cared for in dedicated pediatric/infant CICUs.

Pediatric Normal Values and Z Score Equations for Left and Right Ventricular Strain by Two-Dimensional Speckle-Tracking Echocardiography Derived from a Large Cohort of Healthy Children

BACKGROUND

Strain values vary with age in children and are both vendor and platform specific. Philips QLAB 10.8 and TomTec AutoSTRAIN are two widely used strain analysis platforms, and both incorporate recent European Association of Cardiovascular Imaging/American Society of Echocardiography/Industry Task Force to Standardize Deformation Imaging guidelines. The aims of this study were to establish normal strain values and Z scores for both platforms using a large data set of healthy children and to compare values among these two platforms and a previous version, QLAB 10.5, which predated the task force guidelines.

METHODS

Echocardiograms from 1,032 subjects <21 years old with structurally and functionally normal hearts were included. Images were obtained on the Philips EPIQ platform. Left ventricular (LV) and right ventricular (RV) strain was analyzed using QLAB 10.8 and AutoSTRAIN, and measurement reliability was assessed. Z score equations were derived as a function of age for QLAB 10.8 (LV longitudinal and circumferential strain) and AutoSTRAIN (LV and RV longitudinal strain). A subset (n = 309) was analyzed using QLAB 10.5. Strain values were compared among the three platforms.

RESULTS

For both of the newer platforms, strain varied with age, with magnitude reaching a maximum at 4 to 5 years. For LV longitudinal strain, the largest differences in value were observed in the youngest patients when using QLAB 10.5; the other two platforms were similar. LV circumferential strain measurements (QLAB 10.5 vs QLAB 10.8) were different for all ages, as were measurements of RV longitudinal strain (QLAB 10.8 vs AutoSTRAIN). Reliability was greater for AutoSTRAIN than for QLAB 10.8 and greater for LV than for RV strain.

CONCLUSIONS

Normal RV and LV strain values and Z scores were generated from a large cohort of children for two commonly used platforms in pediatric echocardiography laboratories. Following the incorporation of task force guidelines, the greatest improvement in standardization was seen in infants. Small differences persist between modern platforms; however, these results support the cautious consideration of comparing interplatform measurements.

The role of furosemide and fluid management for a hemodynamically significant patent ductus arteriosus in premature infants

A patent ductus arteriosus (PDA) in infants born premature can present significant management challenges for neonatal providers. Quantifying a hemodynamically significant PDA (hsPDA) represents the first hurdle, however, identifying the best evidence-based approach amongst conservative, pharmacologic, and/or interventional management options has proven to be even more complicated. Within the conservative arm, furosemide to reduce pulmonary edema and improve lung function has spawned several discussions given the concerns for its upregulation of prostaglandin E₂ in the kidneys and conflicting outcomes data. There remains no consensus regarding furosemide use in hsPDAs. In this perspective article, we summarize the approach to defining a hsPDA, review the current practice of furosemide use in the management of hsPDA, and suggest an approach to fluid management and diuresis to address the question: is the routine use of furosemide in hsPDA merited in current practice?

Diagnosis and management of pulmonary hypertension in infants with bronchopulmonary dysplasia

Chronic pulmonary hypertension of infancy (cPHi) is a heterogeneous disease process that contributes to morbidity and mortality in preterm infants. cPHi is most commonly associated with chronic lung disease of prematurity and represents a unique phenotype of bronchopulmonary dysplasia. It is characterized by persistently elevated or newly rising pulmonary vascular resistance and pulmonary artery pressure beyond the first weeks of age. The high-pressure afterload on the right ventricle may or may not be tolerated, depending upon additional cardiovascular shunting and co-morbidities. A comprehensive clinical evaluation combined with advanced hemodynamic assessment by echocardiography and other cardiac imaging modalities help decipher the etiopathologies of disease, identify cardiopulmonary compromise earlier and guide individualized therapeutic intervention tailored by the phenotype. This review summarizes the underlying etiologies, risk factors for development, hemodynamic assessment, management, and follow-up of cPHi in preterm infants. We offer an algorithm for early detection of cPHi and outline research priorities.

The Clinical and Cost Utility of Cardiac Catheterizations in Infants with Bronchopulmonary Dysplasia

OBJECTIVE

To evaluate the cost-utility of catheterization-obligate treatment in preterm infants with pulmonary hypertension, as compared with empiric initiation of sildenafil based on echocardiographic findings alone.

STUDY DESIGN

A Markov state transition model was constructed to simulate the clinical scenario of a preterm infant with echocardiographic evidence of pulmonary hypertension associated with bronchopulmonary dysplasia (BPD) and without congenital heart disease under consideration for the initiation of pulmonary vasodilator therapy via one of two modeled treatment strategies-empiric or catheterization-obligate. Transitional probabilities, costs and utilities were extracted from the literature. Forecast quality-adjusted life-years was the metric for strategy effectiveness. Sensitivity analyses for each variable were performed. A 1000-patient Monte Carlo microsimulation was used to test the durability of our findings.

RESULTS

The catheterization-obligate strategy resulted in an increased cost of $10 778 and 0.02 fewer quality-adjusted life-years compared with the empiric treatment strategy. Empiric treatment remained the more cost-effective paradigm across all scenarios modeled through one-way sensitivity analyses and the Monte Carlo microsimulation (cost-effective in 98% of cases).

CONCLUSIONS

Empiric treatment with sildenafil in infants with pulmonary hypertension associated with BPD is a superior strategy with both decreased costs and increased effectiveness when compared with catheterization-obligate treatment. These findings suggest that foregoing catheterization before the initiation of sildenafil is a reasonable strategy in preterm infants with uncomplicated pulmonary hypertension associated with BPD.

Relationship Between Postnatal Pulmonary Arterial Pressure and Altered Diastolic Function in Neonates with Down Syndrome

OBJECTIVE

To assess the influence of diastolic dysfunction on the evolution of pulmonary hypertension in neonates with Down Syndrome over the early newborn period.

STUDY DESIGN

This was a prospective observational cohort study. Echocardiography was performed three times over the first week of life in both Down syndrome and control cohorts. Measurements of pulmonary arterial pressure in addition to left ventricular (LV) and right ventricular systolic and diastolic function were collected.

RESULTS

Seventy babies with Down syndrome and 60 control infants were enrolled. Forty-eight of the infants with Down syndrome (69%) were born with congenital heart disease (CHD). Echocardiography surrogates of pulmonary hypertension and myocardial function remained significantly impaired in the Down syndrome group in comparison with control infants (all P < .01). In the Down syndrome group, LV early diastolic strain rate was independently associated with measures of pulmonary hypertension while controlling for gestational age, cesarean delivery, and the presence of CHD (P < .01).

CONCLUSIONS

Intrinsic LV diastolic impairment is directly associated with higher indices of pulmonary hypertension in infants with Down syndrome and may be a contributing factor to its evolution.

Rethinking Congenital Heart Disease in Preterm Neonates

Congenital heart disease (CHD) and prematurity are the leading causes of infant mortality in the United States. Importantly, the combination of prematurity and CHD results in a further increased risk of mortality and significant morbidity. The key factors in these adverse outcomes are not well understood, but likely include maternal-fetal environment, perinatal and neonatal elements, and challenging postnatal care. Preterm neonates with CHD are born with "double jeopardy": not only do they experience challenges related to immaturity of the lungs, brain, and other organs, but they also must undergo treatment for cardiac disease. The role of the neonatologist caring for preterm infants with CHD has changed with the evolution of the field of pediatric cardiac critical care. Increasingly, neonatologists invested in the cardiovascular care of the newborn with CHD engage at multiple stages in their course, including fetal consultation, delivery room management, preoperative care, and postoperative treatment. A more comprehensive understanding of prematurity and CHD may inform clinical practice and ultimately improve outcomes in preterm infants with CHD. In this review, we discuss the current evidence surrounding neonatal and cardiac outcomes in preterm infants with CHD; examine the prenatal, perinatal, and postnatal factors recognized to influence these outcomes; identify knowledge gaps; consider research and clinical opportunities; and highlight the ways in which a neonatologist can contribute to the care of preterm infants with CHD.

Definitive Closure of the Patent Ductus Arteriosus in Preterm Infants and Subsequent Short-Term Respiratory Outcomes

A persistent patent ductus arteriosus (PDA) can have significant clinical consequences in preterm infants, depending on the degree of left-to-right shunting, its impact on cardiac performance, and associated perinatal risk factors that can mitigate or exacerbate the shunt. Although the best management strategy remains contentious, PDAs that have contraindications to, or have failed medical management have historically undergone surgical ligation. Recently smaller occluder devices and delivery systems have allowed for minimally invasive closure in the catheterization laboratory even in extremely premature infants. The present review summarizes the pathophysiologic manifestations, treatment options and management of hemodynamically significant PDA in preterm infants. Additionally, we review the available literature surrounding the respiratory support and outcomes of preterm infants following definitive PDA closure.

Near-infrared spectroscopy for perioperative assessment and neonatal interventions

Perioperative applications of near-infrared spectroscopy (NIRS) to monitor regional tissue oxygenation and perfusion in cardiac and noncardiac surgery are of increasing interest in neonatal care. Complex neonatal surgery can impair adequate oxygen delivery and tissue oxygen consumption and increase the risk of neurodevelopmental delay. Coupled with conventional techniques, NIRS monitoring may enable targeted hemodynamic management of the circulation in both cardiac and noncardiac surgical procedures. In this narrative review, we discuss the application of perioperative NIRS in specific neonatal interventions, including surgical intervention for congenital heart defects, definitive closure of the patent ductus arteriosus, neurological and gastrointestinal disorders, and use of extracorporeal membrane oxygenation. We identified areas for future research within disease-specific indications and offer a roadmap to aid in developing evidence-based targeted diagnostic and management strategies in neonates. IMPACT: There is growing recognition that perioperative NIRS monitoring, used in conjunction with conventional monitoring, may provide critical hemodynamic information that either complements clinical impressions or delivers novel physiologic insight into the neonatal circulatory and perfusion pathways.

Cardiac Performance in the First Year of Age Among Preterm Infants Fed Maternal Breast Milk

IMPORTANCE

There is a beneficial association between human breast milk exposure in the neonatal period and cardiac mechanics in adults who were born preterm. It is unknown whether this benefit is apparent in infants in the first year of age.

OBJECTIVE

To test the hypothesis that higher consumption of mother's own milk in preterm infants is associated with enhanced cardiac performance during the first year of age.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study of cardiac and nutritional data at an academic medical center included 80 individuals born preterm and 100 individuals in the control group born full-term. All births were between 2011 and 2013. Two-dimensional echocardiograms were performed at 32 weeks' and 36 weeks' postmenstrual age and at 1 year's corrected age in individuals born preterm and at 1 month and 1 year of age in individuals born full-term. Statistical analysis was performed from January to May 2021.

EXPOSURES

Consumption of mother's own milk.

MAIN OUTCOMES AND MEASURES

Main study outcomes included echocardiography measures of right and left ventricle longitudinal strain (function), left ventricle mass index and right ventricular areas (morphology), and pulmonary vascular resistance (pulmonary hemodynamics) at age 1 year.

RESULTS

Of 180 infants included in the study, 97 (54%) were Black infants and 89 (49%) were female infants. Among the 80 infants born in the preterm cohort, 43 (54%) were female infants and 43 (54%) were Black infants. The median gestational age at birth of the preterm infants was 27.0 weeks (interquartile range, 26.0-28.0 weeks) and the median birth weight was 960 g (interquartile range, 800-1138). For each week of exposure to mother's own milk, preterm infants had greater magnitudes of right ventricular strain (eg, right longitudinal strain: β, 0.021; 95% CI, 0.002-0.041; P < .001) and left ventricular strain (eg, left longitudinal strain: β, 0.065; 95% CI, 0.049-0.080; P = .01), larger right ventricle areas (eg, systolic area: β, 0.026; 95% CI, 0.011-0.042; P = .009), larger left ventricle mass index (β, 0.045; 95% CI, 0.024-0.073; P = .003), and decreased pulmonary vascular resistance (eg, pulmonary artery acceleration time: β, 0.041; 95% CI, 0.018-0.063; P < .001) at 1 year's corrected age, even after accounting for gestational age and common neonatal morbidities. Cardiac values approached those seen in controls born full-term with increased mother's own milk exposure. There were no differences in any of the cardiac indices at 32 weeks' postmenstrual age, but with each week of exposure, right ventricle function (eg, right longitudinal strain: β, 0.016; 95% CI, 0.002-0.031; P < .001) was greater and pulmonary pressured (eg, pulmonary artery acceleration time: β, 0.0032; 95% CI, 0.0013-0.0062; P < .001).

CONCLUSIONS AND RELEVANCE

This study found that preterm infants with higher consumption of mother's own milk had enhanced cardiac performance at age 1 year, suggesting that mother's own milk consumption may play a dynamic modulator role on cardiac mechanics in preterm-born infants and help in normalization of the preterm cardiac phenotype.

Normal Left Ventricular Systolic and Diastolic Strain Rate Values in Children Derived from Two-Dimensional Speckle-Tracking Echocardiography

BACKGROUND

Strain rate (SR) parameters derived from two-dimensional speckle-tracking echocardiography have prognostic value in children with heart disease. Routine use is hindered by a lack of normative data. The aim of this study was to determine reference values and Z scores for left ventricular systolic and diastolic SR in a large cohort of healthy children.

METHODS

Echocardiograms from 577 subjects ≤18 years of age (mean age, 9.6 ± 5.6 years; range, 1 day to 18.0 years; 46% female) with structurally and functionally normal hearts were retrospectively included. Left ventricular longitudinal and circumferential systolic and early and late diastolic SR were measured using two-dimensional speckle-tracking echocardiography from the apical four-chamber and short-axis mid-papillary views. Associations with age and body surface area were assessed using Spearman correlation and generalized additive modeling. The relationship between systolic SR and wall stress (afterload) was examined. Analyses were conducted with and without correction for heart rate. Multivariable linear regression modeling was used to identify independent factors associated with the SR parameters. Z score equations were derived from a selected best-fit parametric model.

RESULTS

All SR parameters differed significantly by age group. The magnitude of all SR values decreased with increasing age and body surface area. Systolic SR magnitude was inversely related to wall stress in children ≤7 years of age but not did not vary significantly in the older age groups. All relationships were maintained after heart rate correction. SR measurements had very good or excellent agreement.

CONCLUSION

Longitudinal and circumferential systolic and diastolic SR parameters are presented from a large cohort of healthy children using two-dimensional speckle-tracking echocardiography from the Philips platform. SR values differ significantly by age and body surface area. These results suggest that the myocardium becomes less sensitive to afterload with maturity. Z score equations based on age are presented, which should promote further clinical and research use.

Primary pulmonary vein stenosis during infancy: state of the art review

Primary pulmonary vein stenosis (PPVS) is an emerging problem among infants. In contrast to acquired disease, PPVS is the development of stenosis in the absence of preceding intervention. While optimal care approaches remain poorly characterized, over the past decade, understanding of potential pathophysiological mechanisms and development of novel therapeutic strategies are increasing. A multidisciplinary team of health care providers was assembled to review the available evidence and provide a common framework for the diagnosis, management, and treatment of PPVS during infancy. To address knowledge gaps, institutional and multi-institutional approaches must be employed to generate knowledge specific to ex-premature infants with PPVS. Within individual institutions, creation of a team comprised of dedicated health care providers from diverse backgrounds is critical to accelerate clinical learning and provide care for infants with PPVS. Multi-institutional collaborations, such as the PVS Network, provide the infrastructure and statistical power to advance knowledge for this rare disease.

Primary Pulmonary Vein Stenosis: A New Look at a Rare but Challenging Disease

Primary pulmonary vein stenosis (PPVS) represents a rare but emerging, often progressive heterogeneous disease with high morbidity and mortality in the pediatric population. Although our understanding of PPVS disease has improved markedly in recent years, much remains unknown regarding disease pathogenesis, distinct disease phenotypes, and patient- and disease-related risk factors driving the unrelenting disease progression characteristic of PPVS. In the pediatric population, risk factors identified in the development of PPVS include an underlying congenital heart disease, prematurity and associated conditions, and an underlying genetic or congenital syndrome. Continued improvement in the survival of high-risk populations, coupled with ongoing advances in general PPVS awareness and diagnostic imaging technologies suggest that PPVS will be an increasingly prevalent disease affecting pediatric populations in the years to come. However, significant challenges persist in both the diagnosis and management of PPVS. Standardized definitions and risk stratification for PPVS are lacking. Furthermore, evidence-based guidelines for screening, monitoring, and treatment remain to be established. Given these limitations, significant practice variation in management approaches has emerged across centers, and contemporary outcomes for patients affected by PPVS remain guarded. To improve care and outcomes for PPVS patients, the development and implementation of universal definitions for disease and severity, as well as evidence-based guidelines for screening, monitoring, cardiorespiratory care, and indications for surgical intervention will be critical. In addition, collaboration across institutions will be paramount in the creation of regionalized referral centers as well as a comprehensive patient registry for those requiring pulmonary vein stenosis.

Pulmonary hypertension and myocardial function in infants and children with Down syndrome

Down Syndrome (DS) is the most common chromosomal abnormality of live born babies. Individuals with DS are at increased risk of cardiopulmonary morbidities in the early neonatal period, infancy and childhood that manifest with elevated pulmonary arterial pressures and altered myocardial performance. Pulmonary hypertension (PH) during the early neonatal period remains under-recognised in this population. PH may occur with or without a congenital heart defect in children with DS and is more common than in the general population. Early detection and continued screening of PH throughout infancy and childhood for these at-risk children is crucial for prompt intervention and potential prevention of long-term sequelae on cardiac function. This review summarises the main physiological concepts behind the mechanisms of PH in children with DS and provides a summary of the current available literature on PH and its impact on myocardial performance.

Updates on Management for Acute and Chronic Phenotypes of Neonatal Pulmonary Hypertension

Neonatal pulmonary hypertension is a heterogeneous disease in term and preterm neonates. It is characterized by persistent increase of pulmonary artery pressures after birth (acute) or an increase in pulmonary artery pressures after approximately 4 weeks of age (chronic); both phenotypes result in exposure of the right ventricle to sustained high afterload. In-depth clinical assessment plus echocardiographic measures evaluating pulmonary blood flow, pulmonary vascular resistance, pulmonary capillary wedge pressure, and myocardial contractility are needed to determine the cause and provide individualized targeted therapies. This article summarizes the causes, risk factors, hemodynamic assessment, and management of neonatal pulmonary hypertension.

Impact of the Vulnerable Preterm Heart and Circulation on Adult Cardiovascular Disease Risk

Preterm birth accounts for over 15 million global births per year. Perinatal interventions introduced since the early 1980s, such as antenatal glucocorticoids, surfactant, and invasive ventilation strategies, have dramatically improved survival of even the smallest, most vulnerable neonates. As a result, a new generation of preterm-born individuals has now reached early adulthood, and they are at increased risk of cardiovascular diseases. To better understand the sequelae of preterm birth, cardiovascular follow-up studies in adolescents and young adults born preterm have focused on characterizing changes in cardiac, vascular, and pulmonary structure and function. Being born preterm associates with a reduced cardiac reserve and smaller left and right ventricular volumes, as well as decreased vascularity, increased vascular stiffness, and higher pressure of both the pulmonary and systemic vasculature. The purpose of this review is to present major epidemiological evidence linking preterm birth with cardiovascular disease; to discuss findings from clinical studies showing a long-term impact of preterm birth on cardiac remodeling, as well as the systemic and pulmonary vascular systems; to discuss differences across gestational ages; and to consider possible driving mechanisms and therapeutic approaches for reducing cardiovascular burden in individuals born preterm.

Changes in the Preterm Heart From Birth to Young Adulthood: A Meta-analysis

CONTEXT

Preterm birth is associated with incident heart failure in children and young adults.

OBJECTIVE

To determine the effect size of preterm birth on cardiac remodeling from birth to young adulthood.

DATA SOURCES

Data sources include Medline, Embase, Scopus, Cochrane databases, and clinical trial registries (inception to March 25, 2020).

STUDY SELECTION

Studies in which cardiac phenotype was compared between preterm individuals born at <37 weeks' gestation and age-matched term controls were included.

DATA EXTRACTION

Random-effects models were used to calculate weighted mean differences with corresponding 95% confidence intervals.

RESULTS

Thirty-two observational studies were included (preterm = 1471; term = 1665). All measures of left ventricular (LV) and right ventricular (RV) systolic function were lower in preterm neonates, including LV ejection fraction (P = .01). Preterm LV ejection fraction was similar from infancy, although LV stroke volume index was lower in young adulthood. Preterm LV peak early diastolic tissue velocity was lower throughout development, although preterm diastolic function worsened with higher estimated filling pressures from infancy. RV longitudinal strain was lower in preterm-born individuals of all ages, proportional to the degree of prematurity (R ² = 0.64; P = .002). Preterm-born individuals had persistently smaller LV internal dimensions, lower indexed LV end-diastolic volume in young adulthood, and an increase in indexed LV mass, compared with controls, of 0.71 g/m² per year from childhood (P = .007).

LIMITATIONS

The influence of preterm-related complications on cardiac phenotype could not be fully explored.

CONCLUSIONS

Preterm-born individuals have morphologic and functional cardiac impairments across developmental stages. These changes may make the preterm heart more vulnerable to secondary insults, potentially underlying their increased risk of early heart failure.

Speckle tracking echocardiographically-based analysis of ventricular strain in children: an intervendor comparison

BACKGROUND

Strain and synchrony can be calculated from a variety of software packages, but there is a paucity of data with inter-vendor comparisons in children. To test the hypothesis that different packages may affect results, independent of acquisition, we compared values obtained using two commercially available analysis tool (QLAB and TomTec), with several different settings.

METHODS

The study population included 108 children; patients were divided into three groups: (1) normal cardiac structure and conduction; (2) ventricular paced rhythm; and (3) flattened ventricular septum (reflecting right ventricular pressure or volume load lesions). We analyzed the same image acquired from the apical 4-chamber (AP4) and short-axis at the mid-papillary level (SAXM) views in both QLAB (versions 10.5 and 10.8) and TomTec (version 1.2). In QLAB version 10.8, low, medium, and high quantification smoothness settings were employed. In TomTec, images were analyzed with both low and high frame rates. Tracking quality for each package was graded. AP4 and SAXM strain and synchrony values were recorded. A mixed-effects linear regression model was used, with main effect considered significant if the p-value was < 0.05.

RESULTS

Tracking scores were high for all packages except QLAB 10.5 in the SAXM view. AP4 and SAXM strain values varied significantly between QLAB 10.5 and the other packages. Synchrony values varied widely for all strain values (p < 0.001 for both) in all packages. Quantification smoothness changes in QLAB 10.8 did not impact strain significantly in any patient group; temporal resolution changes in TomTec resulted in strain differences in children with flat ventricular septums, but not those with normal or ventricular paced hearts.

CONCLUSION

Synchrony values varied substantially among all packages in children. Strain values varied widely between QLAB 10.5 and all other software packages, recommending avoidance of QLAB 10.5 for future studies. Quantification smoothness settings in QLAB 10.8 resulted in minimal strain differences. In TomTec, low and high frame rate strain values differed only in a subset of patients (flattened septum). These data suggest that reliable comparisons between strain values derived from QLAB and TomTec is possible in certain cases, but that caution should be used especially in different hemodynamics conditions.

Preventing disease in the 21st century: early breast milk exposure and later cardiovascular health in premature infants

Cardiovascular health of premature infants reaching early adulthood is an area of ongoing research. There is emerging evidence delineating the challenges faced by those individuals. Young adults born premature demonstrate a unique cardiac phenotype characterized by reduced biventricular volume, relatively lower systolic and diastolic function, and a disproportionate increase in muscle mass. This may clinically manifest by an increased risk of cardiovascular incidents, hypertension, and reduced exercise tolerance. Those consequences appear to result from early postnatal cardiac remodeling due to premature birth and associated co-morbidities. Recent evidence suggests that early exposure to breast milk slows down or even arrests those pathophysiological changes, thereby mitigating the long-term adverse effects of premature birth on cardiovascular health. In this review article, we discuss the role of breast milk in preventing early adulthood cardiovascular disease in infants born premature. We explore the emerging evidence and examine the possible mechanistic pathways mediating this phenomenon. Furthermore, we aim to demonstrate the vital role of early breast milk exposure in preventing cardiovascular disease in preterm infants.

Expanding the phenotypic spectrum of Mabry Syndrome with novel PIGO gene variants associated with hyperphosphatasia, intractable epilepsy, and complex gastrointestinal and urogenital malformations

Mabry syndrome is a glycophosphatidylinositol (GPI) deficiency characterized by intellectual disability, distinctive facial features, intractable seizures, and hyperphosphatasia. We expand the phenotypic spectrum of inherited GPI deficiencies with novel bi-allelic phosphatidylinositol glycan anchor biosynthesis class O (PIGO) variants in a neonate who presented with intractable epilepsy and complex gastrointestinal and urogenital malformations.

Comprehensive Evaluation of Right Heart Performance and Pulmonary Hemodynamics in Neonatal Pulmonary Hypertension : Evaluation of cardiopulmonary performance in neonatal pulmonary hypertension

PURPOSE OF REVIEW

Pulmonary hypertension is characterized by an elevation of pulmonary artery pressures and prolonged exposure of the right ventricle to high afterload that collectively contribute to morbidity and mortality in both the term and preterm infants. This review summarizes the pathogenesis, etiologies, and hemodynamic profiles of the conditions that result in pulmonary hypertension in neonates. We explore the application of echocardiographic techniques for the assessment of right ventricular performance and pulmonary hemodynamics that enhance and guide the diagnosis and management strategies in neonates.

RECENT FINDINGS

Clinical assessments based on the determinants of mean pulmonary artery pressures (pulmonary vascular resistance, pulmonary blood flow, and pulmonary capillary wedge pressure) provide a physiologic approach in determining the acute and chronic etiologies of pulmonary hypertension in neonates. In addition, advances in neonatal echocardiography now afford the capability to obtain quantitative information that often precedes the qualitative information acquired by conventional methods and also provide sensitive markers of right ventricle performance for prognostic information based on the determinants of mean pulmonary artery pressures. Neonatal pulmonary hypertension represents a physiologic spectrum that accounts for the variance in clinical presentation and response to therapies. Physiology-based approaches to etiological identification, coupled with the emerging echocardiographic methods for the assessment of pulmonary hypertension in neonates will likely help to identify cardiovascular compromise earlier, guide therapeutic intervention, monitor therapeutic effectiveness, and improve overall outcome.

Evidence of Echocardiographic Markers of Pulmonary Vascular Disease in Asymptomatic Infants Born Preterm at One Year of Age

OBJECTIVE

To test the hypothesis that echocardiographic markers of pulmonary vascular disease (PVD) exist in asymptomatic infants born preterm at 1-year corrected age.

STUDY DESIGN

We conducted a prospective cohort study of 80 infants born preterm (<29 weeks of gestation) and 100 age- and weight-matched infants born at term and compared broad-based conventional and quantitative echocardiographic measures of pulmonary hemodynamics at 1-year corrected age. Pulmonary artery acceleration time (PAAT), a validated index of pulmonary vascular resistance, arterial pressure, and compliance, was used to assess pulmonary hemodynamics. Lower PAAT is indicative of PVD. Subanalyses were performed in infants with bronchopulmonary dysplasia (BPD, n = 48, 59%) and/or late-onset pulmonary hypertension (n = 12, 15%).

RESULTS

At 1 year, there were no differences between conventional measures of pulmonary hypertension in the infants born at term and preterm. All infants born preterm had significantly lower values of PAAT than infants born at term (73 ± 8 milliseconds vs 98 ± 5 milliseconds, P < .001). Infants born preterm with BPD had even lower PAAT than those without BPD (69 ± 5 milliseconds vs 79 ± 4 milliseconds, P < .01). The degree of PVD at 1-year corrected age was inversely related to gestation in all infants born preterm. Data analysis included adjustment for ventricular function and other confounding factors.

CONCLUSIONS

In comparison with infants born at term, infants born preterm exhibit abnormal PAAT at 1-year corrected age irrespective of neonatal lung disease status, suggesting the existence of PVD beyond infancy. PAAT measurements offer a reliable, noninvasive tool for screening and longitudinal monitoring of pulmonary hemodynamics in infants.

Circulatory Insufficiency and Hypotension Related to the Ductus Arteriosus in Neonates

The biological role of the ductus arteriosus (DA) in neonates varies from an innocent bystander role during normal postnatal transition, to a supportive role when there is compromise to either systemic or pulmonary blood flow, to a pathological state in the presence of hemodynamically significant systemic to pulmonary shunts, as occurs in low birth weight infants. Among a wide array of clinical manifestations arising due to the ductal entity, systemic circulatory insufficiency and hypotension are of significant concern as they are particularly challenging to manage. An understanding of the physiologic interplay between the DA and the circulatory system is the key to developing appropriate targeted therapeutic strategies. In this review, we discuss the relationship of systemic hypotension to the DA, emphasizing the importance of critical thinking and a precise individual approach to intensive care support. We particularly focus on the variable states of hypotension arising directly due to a hemodynamically significant DA or seen in the period following successful surgical ligation. In addition, we explore the mechanistic contributions of the ductus to circulatory insufficiency that may manifest during the transitional period, states of maladapted transition (such as acute pulmonary hypertension of the newborn), and congenital heart disease (both ductal dependent and non-ductal dependent lesions). Understanding the dynamic modulator role of the ductus according to the ambient physiology enables a more precise approach to management. We review the pathophysiology, clinical manifestations, diagnosis, monitoring, and therapeutic intervention for the spectrum of DA-related circulatory compromise.

Application of Neonatologist Performed Echocardiography in the assessment and management of persistent pulmonary hypertension of the newborn

Pulmonary hypertension contributes to morbidity and mortality in both the term newborn infant, referred to as persistent pulmonary hypertension of the newborn (PPHN), and the premature infant, in the setting of abnormal pulmonary vasculature development and arrested growth. In the term infant, PPHN is characterized by the failure of the physiological postnatal decrease in pulmonary vascular resistance that results in impaired oxygenation, right ventricular failure, and pulmonary-to-systemic shunting. The pulmonary vasculature is either maladapted, maldeveloped, or underdeveloped. In the premature infant, the mechanisms are similar in that the early onset pulmonary hypertension (PH) is due to pulmonary vascular immaturity and its underdevelopment, while late onset PH is due to the maladaptation of the pulmonary circulation that is seen with severe bronchopulmonary dysplasia. This may lead to cor-pulmonale if left undiagnosed and untreated. Neonatologist performed echocardiography (NPE) should be considered in any preterm or term neonate that presents with risk factors suggesting PPHN. In this review, we discuss the risk factors for PPHN in term and preterm infants, the etiologies, and the pathophysiological mechanisms as they relate to growth and development of the pulmonary vasculature. We explore the applications of NPE techniques that aid in the correct diagnostic and pathophysiological assessment of the most common neonatal etiologies of PPHN and provide guidelines for using these techniques to optimize the management of the neonate with PPHN.

Deformation imaging and rotational mechanics in neonates: a guide to image acquisition, measurement, interpretation, and reference values

Advances in neonatal cardiac imaging permit a more comprehensive assessment of myocardial performance in neonates that could not be previously obtained with conventional imaging. Myocardial deformation analysis is an emerging quantitative echocardiographic technique to characterize global and regional ventricular function in neonates. Cardiac strain is a measure of tissue deformation and strain rate is the rate at which deformation occurs. These measurements are obtained in neonates using tissue Doppler imaging (TDI) or two-dimensional speckle tracking echocardiography (STE). There is an expanding body of literature describing longitudinal reference ranges and maturational patterns of strain values in term and preterm infants. A thorough understanding of deformation principles, the technical aspects, and clinical applicability is a prerequisite for its routine clinical use in neonates. This review explains the fundamental concepts of deformation imaging in the term and preterm population, describes in a comparative manner the two major deformation imaging methods, provides a practical guide to the acquisition and interpretation of data, and discusses their recognized and developing clinical applications in neonates.

Markers of maternal and infant metabolism are associated with ventricular dysfunction in infants of obese women with type 2 diabetes

BackgroundTo test the hypothesis that infants born to obese women with pre-gestational type 2 diabetes mellitus (IBDMs) have ventricular dysfunction at 1 month that is associated with markers of maternal lipid and glucose metabolism.MethodsIn a prospective observational study of IBDMs (OB+DM, n=25), echocardiographic measures of septal, left (LV) and right ventricular (RV) function, and structure were compared at 1 month of age with those in infants born to OB mothers without DM (OB, n=24) and to infants born to non-OB mothers without DM (Lean, n=23). Basal maternal lipid and glucose kinetics and maternal plasma and infant (cord) plasma were collected for hormone and cytokine analyses.ResultsRV, LV, and septal strain measures were lower in the OB+DM infants compared with those in other groups, without evidence of septal hypertrophy. Maternal hepatic insulin sensitivity, maternal plasma free-fatty-acid concentration, and cord plasma insulin and leptin most strongly predicted decreased septal strain in OB+DM infants.ConclusionIBDMs have reduced septal function at 1 month in the absence of septal hypertrophy, which is associated with altered maternal and infant lipid and glucose metabolism. These findings suggest that maternal obesity and DM may have a prolonged impact on the cardiovascular health of their offspring, despite the resolution of cardiac hypertrophy.

Markers of Cardiovascular Dysfunction in Adolescents With Anorexia Nervosa

Background. Cardiovascular complications contribute to the high morbidity and mortality rate among children with anorexia nervosa (AN). Advances in cardiac imaging permit a more comprehensive assessment of myocardial performance in children that could not be previously obtained with conventional imaging. Myocardial strain analysis is an emerging quantitative echocardiographic technique to characterize global and regional ventricular function in children. Objective. To assess global and regional left ventricular (LV0 function in children newly diagnosed with AN with conventional and quantitative 2-dimensional speckle tracking echocardiographic (2DSTE)–derived strain imaging. Materials. In a cross-sectional study of 30 patients with AN (DSM-5) and 14 age-, sex-, and race-matched healthy children, markers of cardiovascular risk, conventional and 2DSTE measures of LV function, and structure were evaluated and compared. The AN cohort was further stratified by behavioral patterns (restrict, exercise, or purge). Results. Conventional measures and LV global strain were similar between controls and children with AN. A subgroup of AN children with purging behavior had LV remodeling characterized by significantly decreased LV mass index. Regional ventricular function at the apex, as measured by strain, was also decreased in all AN patients. Percent change from ideal body weight, body mass index Z-score, electrolyte profiles, heart rate, and blood pressure were similar. Conclusions. Subclinical regional ventricular dysfunction is present in children with AN. Ventricular remodeling exists in a subgroup of children with AN in association with purging behavior. Future studies may utilize strain imaging to identify those AN patients who are at an increased risk for developing significant cardiac dysfunction.

Normative Left Ventricular M-Mode Echocardiographic Values in Preterm Infants up to 2 kg

BACKGROUND

There is a paucity of normative echocardiographic data in preterm infants. The objectives of this study were to (1) derive left ventricular (LV) M-mode reference values and (2) compare the performance of alternative methods of indexing LV dimensions and LV mass (LVM) in preterm infants. The authors propose that indexing LV measures to weight in preterm infants is a practical approach given the variability associated with tape-measure length measurement in infants.

METHODS

In this retrospective study, LV M-mode echocardiographic measurements of end-diastolic interventricular septal thickness, end-diastolic LV posterior wall thickness, LV end-diastolic and end-systolic dimensions, LVM, and relative wall thickness were remeasured in 503 hospitalized preterm infants ≤2 kg (372 from a retrospective sample and 131 prospectively enrolled). Measures for all variables did not differ between retrospective and prospective samples, so results were pooled. LV dimensions and LVM indexed for weight, length, and body surface area sex-specific centile curves and corresponding Z scores were generated using Cole's lambda-mu-sigma method. Threshold limits (10th and 80th percentiles) were used to generate the normative range for relative wall thickness.

RESULTS

Sex-specific centile curves using LVM, end-diastolic interventricular septal thickness, end-diastolic LV posterior wall thickness, LV end-diastolic dimension, and LV end-systolic dimension indexed to weight were similar to the curves generated using length and body surface area. The mean normal range for relative wall thickness was 0.33 (10th percentile, 0.26; 80th percentile, 0.38).

CONCLUSIONS

From this large cohort of preterm infants, LV M-mode dimension and LVM centile curves indexed to weight were developed as a practical method to assess LV morphology in preterm infants.