Echocardiographic correlates of persistent pulmonary hypertension of the newborn

Progress in the application of echocardiography in neonatal pulmonary hypertension

Purpose: This review aims to overview the use of echocardiography in diagnosing neonatal pulmonary hypertension, assessing cardiac function, and understanding the significance and limitations of various parameters in clinical practice.Materials and methods: Advancements in echocardiography for diagnosing and assessing neonatal pulmonary hypertension, evaluating cardiac function, monitoring treatment effectiveness, and predicting prognosis are discussed.Results: Echocardiography is a pivotal tool for diagnosing and managing neonatal pulmonary hypertension. It should be used with other ultrasound parameters to confirm findings and provide comprehensive analysis for improved accuracy.Conclusion: Understanding the value of echocardiography in neonatal pulmonary hypertension diagnosis and management is crucial. Its integration with other imaging modalities enhances diagnostic accuracy and improves patient outcomes.

Educational Impact of Targeted Neonatal Echocardiography and Hemodynamics Programs on Neonatal-Perinatal Medicine Fellows

OBJECTIVE

Targeted neonatal echocardiography (TNE) is a real-time cardiac imaging modality used by a hemodynamics program to aid in diagnosis, treatment, and monitoring of neonatal cardiovascular illness. This study aimed to describe trainees' perspectives on existing hemodynamics education and perceived impacts of TNE and hemodynamics services on their education.

STUDY DESIGN

This was a mixed quantitative and qualitative study that surveyed neonatal-perinatal medicine (NPM) fellow trainees in Canada and the United States, at programs both with and without a hemodynamics service.

RESULTS

Ninety-two fellows responded to the survey, of whom 24 (26%) were enrolled in a program with an active hemodynamics service, 64 (70%) were training at a program without a hemodynamics service, and 4 (4%) were unsure. Trainees at centers with a hemodynamics service were more satisfied with their cardiovascular physiology education (91 vs. 69%, p = 0.040). Twenty-five percent of all trainees felt they do not have sufficient hemodynamics training to prepare them for independent practice. Areas of knowledge gaps were identified. Bedside teaching combined with didactic teaching was identified as useful means of teaching.

CONCLUSION

Most trainees believed that TNE and a hemodynamics service are valuable educational assets. Thoughtful curriculum design for real-time and consolidation learning, with specific emphasis on content gaps, should be considered.

KEY POINTS

· NPM Fellows perceive TNE & Neonatal Hemodynamics service as a valuable educational opportunity.. · Incorporation of TNE/Hemodynamics teaching into NPM curriculum can enrich trainee experience.. · Combining bedside and classroom teaching is key to successful cardiovascular training..

Targeted Neonatal Echocardiography in the Management of Neonatal Pulmonary Hypertension

Pulmonary hypertension (PH) in neonates, originating from a range of disease states with heterogeneous underlying pathophysiology, is associated with significant morbidity and mortality. Although the final common pathway is a state of high right ventricular afterload leading to compromised cardiac output, multiple hemodynamic phenotypes exist in acute and chronic PH, for which cardiorespiratory treatment strategies differ. Comprehensive appraisal of pulmonary pressure, pulmonary vascular resistance, cardiac function, pulmonary and systemic blood flow, and extrapulmonary shunts facilitates delivery of individualized cardiovascular therapies in affected newborns.

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.

Growth of targeted neonatal echocardiography in Chinese neonatal intensive care units: gaps in practice and training

To evaluate clinical practice, neonatologists' attitudes, and the extent of training and accreditation regarding targeted neonatal echocardiography (TnEcho) among Chinese neonatologists. A web-based questionnaire was emailed to 331 neonatologists across China who completed training in subspecialty neonatology. The survey covered various aspects of TnEcho, including the characteristics of clinical practice, attitudes towards its usefulness, and perceived barriers to implementation and training methods. Survey response rate was 68.0% (225/331). Seventy-nine (35.1%) respondents stated that TnEcho was utilized in their NICUs. Most respondents reported the use of echocardiography to evaluate hemodynamic significance of the patent ductus arteriosus (PDA, 94.9%). The eyeballing technique was most used to evaluate left (82.3%) and right (77.2%) ventricular function. Most respondents (87.3-96.2%) positively valued the role of TnEcho in providing timely and longitudinal hemodynamic information to guide cardiovascular care. Access to TnEcho was more likely in centers with on-site pediatric cardiology service (p = .003), larger bed capacity (p = .004), or level IV status (p = .003). Lack of experienced practitioners with echocardiography expertise (88.9%) and accredited training programs (85.8%) was perceived to be the major barrier to implementation. Of concern, most practitioners with TnEcho skills received training in an informal manner through workshops (60.8%) or self-directed learning (54.4%). Conclusions: The use of TnEcho for longitudinal evaluation of infants with hemodynamic instability is growing within Chinese NICUs. There is an urgent need to develop standardized training programs and accreditation for TnEcho which are adapted to the Chinese context.

Diastolic ventricular function in persistent pulmonary hypertension of the newborn

Background

Persistent pulmonary hypertension of the newborn (PPHN) is usually considered a consequence of impaired pulmonary circulation. However, little is known regarding the role of cardiac dysfunction in PPHN. In this study, we hypothesized that the tolerance for pulmonary hypertension in newborn infants depends on the biventricular function. The aim of this study is to evaluate biventricular cardiac performance by using Tissue Doppler Imaging (TDI) in an healthy newborn infants with asymptomatic pulmonary hypertension and in newborn infants with PPHN.

Methods

Right and left cardiac function were investigated using conventional imaging and TDI in 10 newborn infants with PPHN ("PPHN") and 10 asymptomatic healthy newborn infants ("asymptomatic PH").

Results

Systolic pulmonary artery pressure (PAP) as assessed by TDI and the mean systolic velocity of the right ventricular (RV) free wall were similar in both groups. The isovolumic relaxation time of the right ventricle at the tricuspid annulus was significantly longer in the "PPHN" than in the "asymptomatic PH" group (53 ± 14 ms vs. 14 ± 4 ms, respectively; p < 0.05). Left ventricular (LV) function was normal in both groups with a systolic velocity (S'LV) at the LV free wall groups (6 ± 0.5 cm/s vs. 8.3 ± 5.7 cm/s, p > 0.05).

Conclusion

The present results suggest that high PAP with or without respiratory failure is not associated with altered right systolic ventricular function and does not affect LV function in newborn infants. PPHN is characterized by a marked right diastolic ventricular dysfunction. These data suggest that the hypoxic respiratory failure in PPHN results, at least in part, from diastolic RV dysfunction and right to left shunting across the foramen ovale. We propose that the severity of the respiratory failure is more related to the RV diastolic dysfunction than the pulmonary artery pressure.

Predicting the Severity and Outcome of Persistent Pulmonary Hypertension of the Newborn Using New Echocardiography Parameters

OBJECTIVE

To examine echocardiographic (ECHO) parameters correlation with clinical severity indices, Alveolar- arterial gradient (A-a gradient), oxygenation index (OI) and clinical outcomes in newborns with persistent pulmonary hypertension of the newborn (PPHN).

STUDY DESIGN

Retrospective cohort study of 67 subjects, >35 weeks' gestation with the diagnosis of PPHN admitted to the University of Kentucky neonatal intensive care unit (NICU) between September 2014 and December 2016.

RESULTS

High left ventricular end-systolic eccentricity index (EIs) correlates with the overall clinical severity of PPHN as it is associated with higher A-a gradient and OI (p=0.0003 and p<0.0001, respectively). Elevated EIs was also predictive for the use of inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation (ECMO) (p=0.0004 and p<0.0001, respectively). EIs value of >1.38 provides cutoff value as an objective marker for the need for ECMO.

CONCLUSION

EIs can be used to assess clinical severity and outcomes and should be reported routinely. Further studies are warranted to confirm these results.

Ventricular function in congenital diaphragmatic hernia: a systematic review and meta-analysis

There is emerging evidence supporting ventricular function as a prognostic factor in congenital diaphragmatic hernia (CDH). The present systematic review and meta-analysis aimed to determine the predictive value of early ventricular function for survival and extracorporeal membrane oxygenation (ECMO) requirement in newborns with CDH. PubMed, Google Scholar, Cochrane Central Register, Clinical Trial Registry, and Opengrey were accessed. Studies evaluating associations between echocardiographic ventricular function measured ≤ 48 h after birth and survival or ECMO requirement were included. Two independent authors extracted the following data: study and participant characteristics, prognostic factors, and outcome-related data. Eleven studies met the inclusion criteria. Five studies reported on survival, two on ECMO, and four on both outcomes. A moderate risk of bias was found in most of the studies, mainly because of selection, prognostic factors, and confounding biases. For survival (899 participants), pooled sensitivity and specificity were 86% (95% confidence interval [CI], 77-92%) and 44% (95% CI, 25-65%), respectively, in normal left ventricular function. For ECMO need (815 participants), pooled sensitivity and specificity were 39.8% (95% CI, 27-52%) and 88% (95% CI, 80-96%), respectively, in left ventricular dysfunction. Overall certainty of the evidence was graded very low for survival and low for ECMO. Inconsistent reporting of echocardiographic measurements and lack of adjustment for confounding factors were major limitations.Conclusion: Early ventricular dysfunction is a potential prognostic factor in CDH. Standardized echocardiographic measurement reporting and high-quality studies are needed to further elucidate its prognostic significance. What is Known: • Evidence supports the predictive value of echocardiographic measurements in CDH ≤ 24-48 h post-birth. • Ventricular dysfunction has been proposed as a prognostic risk factor. What is New: • Right and left ventricular functions were promising predictors of survival and ECMO requirement in neonates with CDH. • Test characteristics of ventricular function were determined as predictors of survival or need for ECMO. Specific echocardiographic markers of ventricular function can be valuable in determining prognosis.

Care of the critically ill neonate with hypoxemic respiratory failure and acute pulmonary hypertension: framework for practice based on consensus opinion of neonatal hemodynamics working group

Circulatory transition after birth presents a critical period whereby the pulmonary vascular bed and right ventricle must adapt to rapidly changing loading conditions. Failure of postnatal transition may present as hypoxemic respiratory failure, with disordered pulmonary and systemic blood flow. In this review, we present the biological and clinical contributors to pathophysiology and present a management framework.

Fetal Cardiac Function: Myocardial Performance Index

The Myocardial Performance Index (MPI) or Tei index, presented by Tei in 1995, is the ratio of the sum of the duration of the isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) to the duration of the ejection time (ET). The Modified Myocardial Performance Index (Mod-MPI), proposed in 2005, is considered a reliable and useful tool in the study of fetal heart function in several conditions, such as growth restriction, twin-twin transfusion syndrome, maternal diabetes, preeclampsia, intrahepatic cholestasis of pregnancy, and adverse perinatal outcomes. Nevertheless, clinical translation is currently limited by poorly standardised methodology as variations in the technique, machine settings, caliper placement, and specific training required can result in significantly different MPI values. This review aims to provide a survey of the relevant literature on MPI, present a strict methodology and technical considerations, and propose future research.

Cardiac Function and Ventricular Interactions in Persistent Pulmonary Hypertension of the Newborn

OBJECTIVES

The aim of this study was to use a comprehensive imaging protocol to identify echocardiographic correlations of right and left ventricular size, function, and hemodynamics in neonates with persistent pulmonary hypertension of newborn and describe their relationship with key clinical variables.

DESIGN

Retrospective case-control echocardiography-based study of persistent pulmonary hypertension of newborn.

SETTING

A tertiary neonatal ICU in Canada.

PATIENTS

Forty-nine neonates (gestational age ≥ 35 wk old) diagnosed with persistent pulmonary hypertension of newborn within first 3 days after birth and 50 age-matched controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The echocardiographic measurements comprised of right ventricular and left ventricular functional markers, including tricuspid annular plane systolic excursion, fractional area change, tissue Doppler imaging, and deformation imaging. Sample size was based on detecting an intergroup difference of 10% in tricuspid annular plane systolic excursion, which was considered the primary outcome. Linear correlations between the right and left ventricular indices, as well as their association with the outcome of death or extracorporeal membrane oxygenation were evaluated. Persistent pulmonary hypertension of newborn was associated with lower tricuspid annular plane systolic excursion (6.81 ± 1.92 vs 9.25 ± 1.30 mm), right-ventricular global longitudinal strain (16.9% ± 5.4% vs -21.6% ± 4.6%); left ventricular ejection fraction (49% ± 7% vs 55% ± 6%), left ventricular global longitudinal strain (-16.7% ± 3.3% vs -21.4% ± 2.0%) (all p < 0.01). Right and left ventricular diastolic and global function was also lower in persistent pulmonary hypertension of newborn, with more pronounced changes seen for the right ventricle. Moderate-to-strong linear correlations were observed between the right and left ventricular functional markers, with right ventricular global longitudinal strain and left ventricular global longitudinal strain being the strongest (r = 0.8). Within persistent pulmonary hypertension of newborn group, hypoxic ischemic encephalopathy was associated with lower right and left ventricular systolic and right ventricular diastolic performance. Tricuspid annular plane systolic excursion (p =0.08) and left ventricular systolic velocity (p = 0.09) tended to be lower in patients who subsequently died/needed extracorporeal membrane oxygenation.

CONCLUSIONS

Persistent pulmonary hypertension of newborn is characterized by global cardiac dysfunction, involving both the right and left ventricles, with significant interventricular functional correlation. Cardiac dysfunction early in disease course may identify patients at highest risk of adverse outcome.

Relationship Between Left Ventricular Geometry and Invasive Hemodynamics in Pediatric Pulmonary Hypertension

Background Ventricular septal flattening, frequently present in pulmonary hypertension (PH), can be quantified using eccentricity index (EI). EI has not been evaluated by concurrent echocardiography and cardiac catheterization and traditionally does not account for postsystolic septal flattening, often seen in PH. We evaluated left ventricular shape, including a novel measure of maximal EI to account for postsystolic septal flattening, to establish the relationship with concurrent invasive hemodynamics. Methods Echocardiography was performed at 2 institutions in 78 pediatric PH patients during cardiac catheterization and in 78 matched controls. From midpapillary parasternal short-axis views, EI and right-to-left ventricular diameter ratio were assessed. Results EI and right-to-left ventricular measures were significantly increased in PH compared with controls. Shape measures correlated with invasive hemodynamics and PH outcome measures (PH-related hospitalization, functional class, medical therapy escalation, and BNP [brain natriuretic peptide]). End-systolic EI of 1.16 best identified the presence of PH, whereas a maximal EI of 1.42 and 1.94 best identified half-systemic and systemic PH, respectively. A maximal EI of 1.27 was associated with an odds ratio of 16.16 (95% CI, 6.62-39.46) for PH-related hospitalization or escalation of therapy. Conclusions Using simultaneous echocardiography and catheterization in the largest study population to date, we demonstrate that EI and right-to-left ventricular ratio correlate with invasive hemodynamics and outcomes measures, and EI can accurately define those with clinically important PH. These measures strengthen the ability of echocardiography to identify and follow pediatric PH patients, especially in the absence of methods to quantify right ventricular systolic pressures.

Individualized Hemodynamic Management in Newborns

In our aim to improve patient outcome we are transitioning from a "one-size-fits-all" protocolized approach toward an individualized hemodynamic management, that is tailored to the cardiovascular (patho-)physiology and the specific clinical characteristics of each individual patient. In this narrative review an overview is provided about an individualized approach toward various neonatal hemodynamic conditions.

Echocardiographic prediction of severe pulmonary hypertension in neonates undergoing therapeutic hypothermia for hypoxic-ischemic encephalopathy

OBJECTIVE

Among neonates undergoing whole body cooling for hypoxic-ischemic encephalopathy (HIE), to compare ventricular function in the presence and absence of pulmonary hypertension (PPHN) needing inhaled nitric oxide (iNO)/ECMO.

DESIGN

This retrospective study included infants with HIE who underwent cooling. ECHO (<24 h age) measures, RV fractional area change (FAC), RV Tricuspid annular plane systolic excursion (TAPSE), myocardial performance indices (MPI), and the RV systolic to diastolic duration (S/D) ratio were evaluated.

RESULTS

The iNO/ECMO group (n = 26) had lower TAPSE and RV FAC and higher RV MPI and S/D, compared with controls (n = 39). Area under the curve was highest for RV S/D, with fair sensitivity (95% CI) [76.9 (56.3-91%)] and negative predictive value [78.6 (63.3-88.6%)] for subsequent iNO/ECMO at cutoff >1.45.

CONCLUSIONS

Infants with HIE undergoing cooling who progressed to iNO/ECMO for PPHN had RV dysfunction on early ECHO; S/D had the best predictive performance. RV S/D may be a useful early marker of PPHN in HIE.

New Modalities for the Administration of Inhaled Nitric Oxide in Intensive Care Units After Cardiac Surgery or for Neonatal Indications: A Prospective Observational Study

BACKGROUND

Nitric oxide (NO) has a well-known efficacy in pulmonary hypertension (PH), with wide use for 20 years in many countries. The objective of this study was to describe the current use of NO in real life and the gap with the guidelines.

METHODS

This is a multicenter, prospective, observational study on inhaled NO administered through an integrated delivery and monitoring device and indicated for PH according to the market authorizations. The characteristics of NO therapy and ventilation modes were observed. Concomitant pulmonary vasodilator treatments, safety data, and outcome were also collected. Quantitative data are expressed as median (25th, 75th percentile).

RESULTS

Over 1 year, 236 patients were included from 14 equipped and trained centers: 117 adults and 81 children with PH associated with cardiac surgery and 38 neonates with persistent PH of the newborn. Inhaled NO was initiated before intensive care unit (ICU) admission in 57%, 12.7%, and 38.9% with an initial dose of 10 (10, 15) ppm, 20 (18, 20) ppm, and 17 (11, 20) ppm, and a median duration of administration of 3.9 (1.9, 6.1) days, 3.8 (1.8, 6.8) days, and 3.1 (1.0, 5.7) days, respectively, for the adult population, pediatric cardiac group, and newborns. The treatment was performed using administration synchronized to the mechanical ventilation. The dose was gradually decreased before withdrawal in 86% of the cases according to the usual procedure of each center. Adverse events included rebound effect for 3.4% (95% confidence interval [CI], 0.9%-8.5%) of adults, 1.2% (95% CI, 0.0%-6.7%) of children, and 2.6% (95% CI, 0.1%-13.8%) of neonates and methemoglobinemia exceeded 2.5% for 5 of 62 monitored patients. Other pulmonary vasodilators were associated with NO in 23% of adults, 95% of children, and 23.7% of neonates. ICU stay was respectively 10 (6, 22) days, 7.5 (5.5, 15) days, and 9 (8, 15) days and ICU mortality was 22.2%, 6.2%, and 7.9% for adults, children, and neonates, respectively.

CONCLUSIONS

This study confirms the safety of NO therapy in the 3 populations with a low rate of rebound effect. Gradual withdrawal of NO combined with pulmonary vasodilators are current practices in this population. The use of last-generation NO devices allowed good compliance with recommendations.

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.

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.

Biventricular function on early echocardiograms in neonatal hypoxic-ischaemic encephalopathy

AIM

To compare early (<24 hours) echocardiograms (ECHOs) in infants with perinatal hypoxic-ischaemic encephalopathy (HIE) undergoing (i) therapeutic hypothermia (TH), (ii) normothermia and (iii) normal controls.

METHODS

This was a single-centre retrospective review of clinical early ECHOs of term infants with moderate or severe HIE and controls (with a normal ECHO <72 hours of age). Right (RVO) and left ventricular output (LVO), RV and LV myocardial performance index (MPI), systolic to diastolic duration ratio (S/D) and eccentricity indices (EI) in systole and diastole were compared using ANOVA.

RESULTS

Among infants with HIE (n = 56, 38 in the TH and 18 in normothermia groups), 14 (25%) infants died and 42 survived. Significantly elevated biventricular MPI, lower RVO and LVO and pulmonary hypertension (abnormal EI, higher RV S/D and bidirectional or right-to-left ductal shunt) were found in groups with HIE, compared to controls (n = 35). LV MPI was lower in HIE-TH, compared to the HIE-normothermia group. Infants with HIE who died (n = 14) had a significantly lower EId [0.77 (0.09) vs. 0.83 (0.08), p = 0.021] compared to survivors (n = 42).

CONCLUSION

Infants with perinatal HIE have ventricular dysfunction; those who died had significantly lower EId than survivors; this association needs to be further validated.

Left Ventricular Function in Healthy Term Neonates During the Transitional Period

OBJECTIVES

To evaluate whether incorporating conventional, tissue Doppler imaging and speckle tracking echocardiography are reliable and can characterize changes in left ventricular (LV) function properly in healthy neonates in the early transitional newborn period.

STUDY DESIGN

A prospective observational study was conducted in 50 healthy term neonates with a mean ± SD gestational age and birth weight of 39.3 ± 1.2 weeks and 3.5 ± 0.44 kg, respectively. All infants underwent serial echocardiograms at 15 ± 2 (day 1) and 35 ± 2 hours (day 2) of age. The LV dimensions and various functional indices including tissue Doppler imaging velocities and speckle tracking echocardiography-derived peak longitudinal strain, and systolic and diastolic strain rate were acquired and compared between time points.

RESULTS

All measurements were feasible from each scan except speckle tracking echocardiography in 10% and 20% of images on days 1 and 2 of age, respectively. LV dimensions, but not functional measures, demonstrated a small to moderate positive correlation with birth weight. On day 2, a small reduction was observed in LV basal diameter, mitral valve inflow velocity time integral, and systolic velocity of the lateral wall and septum. Other indices remained unchanged. Tissue Doppler imaging-derived functional and flow-derived hemodynamic measures demonstrated the least measurement bias, and strain measurements demonstrated better reliability than strain rate, fractional shortening, and ejection fraction.

CONCLUSION

The relative reliability of various echocardiographic indices to quantify LV function in neonates establish a normative dataset and provide evidence for their validity during the first 2 days of life.