Tissue Doppler velocity imaging and event timings in neonates: a guide to image acquisition, measurement, interpretation, and reference values

The effect of heart rate on systolic and diastolic time intervals and cardiac function in stable and sick preterm infants

BACKGROUND

Diastolic function includes relaxation and filling of the heart and is dependent on heart rate (HR) and time spent in either systole (St) or diastole (Dt). The St/Dt ratio increases as HR increased and is a marker of overall cardiac function in children with heart failure. The aim of this study is to describe cardiac cycle events in preterm infants.

METHODS

Cardiac ultrasounds of preterm infants <32 weeks were retrospectively reviewed for cardiac cycle events from Tissue Doppler images and grouped by clinical indication of the scan as stable or as clinical deterioration with significant illness.

RESULTS

412 scans in 201 preterm infants were analyzed. St/Dt ratio increased with increasing HR. St increased from 50 to 54 % of the cardiac cycle length with shortened diastolic duration. Isovolumetric contraction and relaxation remained unchanged at 9 and 12 % of the cardiac cycle respectively. Mean St, Dt and St/Dt ratio in stable infants were 195(19) msec, Dt 175(24) msec and 1.13 (0.16) respectively. Sick infants without cardiovascular medications showed a significantly shorter St and lower St/Dt ratio. Cardiovascular medications increased isovolumetric times, Dt, and early diastolic duration.

CONCLUSION

Reference values for cardiac cycle durations and St/Dt ratio are presented. Preterm hearts adapt to higher HR by shifting towards systole and shortened early diastole by optimising its force frequency relationship and enhanced relaxation. The St/Dt ratio was altered in preterm infants with significant illness. This simple ultrasound marker could be tested in further studies that investigate cardiovascular medications in preterm infants.

Clinical and echocardiographic predictors of medical therapy failure for patent ductus arteriosus closure in preterm infants: Insights from a risk-based treatment approach

OBJECTIVE

This study aims to identify initial clinical and echocardiographic markers in preterm infants which may predict failure of medical therapy to close a high-risk patent ductus arteriosus (PDA).

STUDY DESIGN

This was an observational cohort study conducted in a level III NICU. Infants born <29 weeks gestation were treated with medical therapy if they were deemed high-risk as per the EL-Khuffash PDA Severity Score (PDAsc). Treatment-failure infants were compared to treatment-success infants.

RESULTS

110 infants were high-risk (58 responders, 52 non-responders). Initial differences in clinical and echocardiographic characteristics between infants in the treatment-failure and treatment-success groups, respectively, included a lower gestational age (25.2 ± 1.3 vs 25.9 ± 1.4; p < 0.01), higher PDAsc (7.8 ± 1.9 vs 7.0 ± 1.5; p < 0.01), lower incidence of pre-eclampsia (3 (6 %) vs 12 (21 %); p = 0.02), lower mitral E:A ratio (0.78 ± 0.13 vs 0.90 ± 0.27; p = 0.02), higher LA:Ao ratio (1.7 ± 0.6 vs 1.4 ± 0.5; p = 0.02), lower celiac artery systolic velocity(m/s) (0.36 ± 0.12 vs 0.46 ± 0.20; p = 0.02) and higher global longitudinal strain (GLS) (%) (20.8 ± 3.1 vs 18.1 ± 4.4; p < 0.01). In a multivariate logistic regression model, GLS remained the only independent predictor of medical therapy failure (OR 0.83, 95 % CI 0.70-0.98, p = 0.03).

CONCLUSION

These findings highlight a distinct subgroup of high-risk preterm infants who are unlikely to respond to medical therapy, emphasising the need for an individualised approach to PDA management. Integrating clinical and echocardiographic markers with risk-based scoring systems may improve early identification of treatment non-responders and guide alternative therapeutic strategies.

Hemodynamic precision to guide surgical timing for neonates with congenital diaphragmatic hernia: a narrative review

Despite a near universal approach focused on physiologic stabilization prior to surgical repair of congenital diaphragmatic hernia (CDH), a condition with significant morbidity and mortality, there remains a lack of consensus, or even guidance, on the appropriate timing for diaphragmatic reconstruction. Hemodynamic-directed care has increasingly been incorporated into the post-natal, peri-operative care of CDH, including assessments of pulmonary hypertension and ventricular dysfunction. Herein, we discuss the integration of targeted neonatal echocardiography and hemodynamic-based assessments to guide precision-directed care and inform selection of the optimal surgical repair window in this complex, heterogeneous patient population.

Characterizing the Role of Left Ventricular Indices and Biventricular Interaction in Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension in Extreme Prematurity

INTRODUCTION

Bronchopulmonary dysplasia (BPD) is a common respiratory morbidity in preterm infants. The onset of pulmonary hypertension leads to worse respiratory outcomes. The contribution of left ventricular diastolic dysfunction in BPD-PH is well reported. We evaluated the serial left ventricular function and possible ventricular interdependence among BPD-PH.

METHODS

This is a single-center, prospective observational study. Infants <28 weeks of gestation are included.

RESULTS

Eighty infants were enrolled. The incidence of BPD-PH was 23%. The BPD-PH group had a high incidence of hemodynamically significant ductus arteriosus (83% vs. 56%, p < 0.018), longer oxygen days (96.2 ± 68.1 vs. 59.35 ± 52, p < 0.008), and prolonged hospital stay (133.8 ± 46 vs. 106.5 ± 38 days, p < 0.005). Serial tissue Doppler imaging showed prolonged left ventricle (LV) isovolumetric contraction time (IVCT) (31.05 ± 3.3 vs. 26.8 ± 4.4 ms, p < 0.001) and myocardial performance index (MPI) (0.43 ± 0.03 vs. 0.37 ± 0.04, p < 0.001) from 33 weeks. The changes in IVCT (35.9 ± 6.7 vs. 27.9 ± 4.5 ms, p < 0.001), isovolumetric relaxation time (IVRT) (50 ± 6.5 vs. 39.9 ± 5.8 ms, p < 0.001), and MPI (0.48 ± 0.05 vs. 0.36 ± 0.03, p < 0.001) persisted at 36 weeks. The receiver operator characteristic curve showed LV MPI >40 has 83% sensitivity and 65% specificity (AUC: 0.77, p < 0.001) in the diagnosis of PH. The BPD-PH group had a higher LV E/E' ratio (13.1 ± 4.4 vs. 11.4 ± 3.4, p < 0.02). Pearson correlation test showed a moderate positive correlation between RV MPI and LV MPI (r = 0.585, p < 0.001).

CONCLUSIONS

Significant LV diastolic dysfunction was observed in BPD-PH. This is the first study to show biventricular strain and possible ventricular interdependence in BPD-PH. The prolonged LV IVRT and MPI may be a novel echocardiographic indicator of BPD-PH.

Diabetes in pregnancy and offspring cardiac function: a systematic review and meta-analysis

Introduction

Diabetes in pregnancy is associated with impaired offspring cardiac function. The objective of this systematic review was to determine the effect of diabetes in pregnancy on cardiac function in the offspring measured by echocardiography.

Methods

PubMed, Embase, Cochrane CENTRAL and Web of Science databases were searched from 1992 to June 27, 2023. Studies reporting offspring (age < 18 years) cardiac function by echocardiography compared between any type of diabetes in pregnancy and healthy control pregnancies were included. Study selection, quality assessment and risk of bias was independently performed by two reviewers. Meta-analyses was performed where possible.

Results

Thirty-one observational studies were included 1,679 cases and 2,694 controls. In the first week of life (23 studies, n = 2,663), intraventricular septum diastolic diameter (hypertrophy) was increased, while myocardial performance index (global function) and LV E/A-ratio (diastolic function) were decreased. No difference was found for left ventricular ejection fraction (systolic function). At 1-6 months (4 studies, n = 454) studies found hypertrophy, and decreased global function, but no difference in systolic or diastolic function. At 1-8 years (7 studies, n = 1,609) no difference was found. The available data did not allow for sub-analysis based on the type of diabetes, treatment, or glycemic control.

Conclusions

Diabetes in pregnancy is associated with cardiac hypertrophy and impaired global cardiac function in infants up to six months old. The few studies reporting on older children found no difference in the parameters investigated. Longitudinal studies employing more advanced echocardiographic measures or MRI are needed to evaluate consequences for long-term cardiac health.

Systematic Review Registration

https://www.crd.york.ac.uk/, identifier (CRD42022312471).

Global longitudinal strain is an informative index of left ventricular performance in neonates receiving intensive care

Echocardiographic assessment of left ventricular function is crucial in NICU. The study aimed to compare the accuracy and agreement of global longitudinal strain (GLS) with conventional measurements. Real-life echocardiograms of neonates receiving intensive care were retrospectively reviewed. Shortening fraction (SF), ejection fraction (EF) and S' measurements were retrieved from health records. GLS was calculated offline from stored images. The association with stroke volume indexed for body weight (iSV) was evaluated by regression analysis. The diagnostic ability to identify uncompensated shock was assessed by ROC curve analysis. Cohen's κ was run to assess agreement. 334 echocardiograms of 155 neonates were evaluated. Mean ± SD gestational age and birth weight were 34.5 ± 4.1 weeks and 2264 ± 914 g, respectively. SF, EF, S' and GLS were associated with iSV with R2 of 0.133, 0.332, 0.252 and 0.633, (all p < .001). Including all variables in a regression model, iSV prediction showed an adjusted R2 of 0.667, (p < .001). GLS explained 73% of the model variance. GLS showed a better ability to diagnose uncompensated shock (AUC 0.956) compared to EF, S' and SF (AUC 0.757, 0.737 and 0.606, respectively). GLS showed a moderate agreement with EF (κ = .500, p < .001) and a limited agreement with S' and SF (κ = .260, p < .001, κ = .242, p < .001). GLS was a more informative index of left ventricular performance, providing the rationale for a more extensive use of GLS at the cotside.

Serial tissue Doppler imaging in the evaluation of bronchopulmonary dysplasia-associated pulmonary hypertension among extremely preterm infants: a prospective observational study

Objectives

To evaluate serial tissue Doppler cardiac imaging (TDI) in the evolution of bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH) among extremely preterm infants.

Design

Prospective observational study.

Setting

Single-center, tertiary-level neonatal intensive care unit.

Patients

Infant born <28 weeks gestation.

Main outcome measures

Utility of TDI in the early diagnosis and prediction of BPD-PH and optimal timing for screening of BPD-PH.

Results

A total of 79 infants were included. Of them, 17 (23%) had BPD-PH. The mean gestational age was 25.9 ± 1.1 weeks, and mean birth weight was 830 ± 174 g. The BPD-PH group had a high incidence of hemodynamically significant patent ductus arteriosus (83% vs. 56%, p < 0.018), longer oxygen days (96.16 ± 68.09 vs. 59.35 ± 52.1, p < 0.008), and prolonged hospital stay (133.8 ± 45.9 vs. 106.5 ± 37.9 days, p < 0.005). The left ventricular eccentricity index (0.99 ± 0.1 vs. 1.1 ± 0.7, p < 0.01) and the ratio of acceleration time to right ventricular ejection time showed a statistically significant trend from 33 weeks (0.24 ± 0.05 vs. 0.28 ± 0.05, p < 0.05). At 33 weeks, the BPD-PH group showed prolonged isovolumetric contraction time (27.84 ± 5.5 vs. 22.77 ± 4, p < 0.001), prolonged isovolumetric relaxation time (40.3 ± 7.1 vs. 34.9 ± 5.3, p < 0.003), and abnormal myocardial performance index (0.39 ± 0.05 vs. 0.32 ± 0.03, p < 0.001). These differences persisted at 36 weeks after conceptional gestational age.

Conclusions

TDI parameters are sensitive in the early evolution of BPD-PH. Diagnostic accuracy can be increased by combining the TDI parameters with conventional echocardiographic parameters. BPD-PH can be recognizable as early as 33-34 weeks of gestation.

Tissue-Tracking Mitral Annular Displacement in Neonates: A Novel Index of Left Ventricular Systolic Function

OBJECTIVES

To assess the feasibility, accuracy, and reproducibility of tissue-tracking mitral annular displacement (TMAD) compared with other measures of left ventricular systolic function in healthy preterm and term neonates in the transitional period.

METHODS

This was a prospective observational study. Two echocardiograms were performed at 24 and 48 hours of life. TMAD, shortening fraction (SF), ejection fraction (EF), s', and global longitudinal strain (GLS) were measured offline. Accuracy to detect impaired GLS was tested by ROC curve analysis. DeLong test was used to compare AUCs. Intra and interobserver reproducibility of the off-line analysis was calculated.

RESULTS

Mean ± SD gestational age and weight were 34.2 ± 3.8 weeks and 2162 ± 833 g, respectively. TMAD was feasible in 168/180 scans (93%). At 24 hours the AUC (95% CI) of SF, EF, s', and TMAD (%) was 0.51 (0.36-0.67), 0.68 (0.54-0.82), 0.63 (0.49-0.77), and 0.89 (0.79-0.99) respectively. At 48 hours the AUC (95% CI) of SF, EF, s', and TMAD (%) was 0.64 (0.51-0.77), 0.59 (0.37-0.80), 0.70 (0.54-0.86), and 0.96 (0.91-1.00), respectively. The AUC of TMAD was superior to the AUC of SF, EF, s', at both timepoints (P < .02). Intraclass correlation coefficients (95% CI) of intra and interobserver reproducibility of TMAD were 0.97 (0.95-0.99) and 0.94 (0.88-0.97), respectively.

CONCLUSION

TMAD showed improved accuracy and optimal reproducibility in neonates in the first 48 hours of life.

Haemodynamic assessment and management of hypotension in the preterm

The management of low blood flow states in premature neonates is fraught with many challenges. We remain over-reliant on regimented stepwise protocols that use mean blood pressure as a threshold for intervention to guide treatment, without giving due consideration to the underlying pathophysiology. The current available evidence does not reflect the need to concentrate on the unique pathophysiology of the preterm infant and thus leads to widespread misuse of vasoactive agents that often do not provide the desired clinical effect. Therefore, understanding the underlying pathophysiological underpinnings of haemodynamic compromise may better guide choice of agent and assess physiological response to the selected intervention.

Echocardiography Assessment of Left Ventricular Function in Extremely Preterm Infants, Born at Less Than 28 Weeks' Gestation, With Bronchopulmonary Dysplasia and Systemic Hypertension

BACKGROUND

The survival of smaller and more immature premature infants has been associated with lifelong cardiorespiratory comorbidities. Infants with bronchopulmonary dysplasia (BPD) undergo routine screening echocardiography to evaluate for development of chronic pulmonary hypertension, a late manifestation of pulmonary vascular disease.

METHODS

Our aim was to evaluate left ventricular (LV) performance in infants with BPD and pulmonary vascular disease who developed systemic hypertension. We hypothesized that infants with hypertension were more likely to have impaired LV performance. We present a single-center cross-sectional study of premature infants born at less than 28 0/7 weeks' gestational age with a clinical diagnosis of BPD. Infants were categorized by the systolic arterial pressure (SAP) at time of echocardiography as hypertensive (SAP ≥90 mm Hg) or normotensive (SAP <90 mm Hg). Sixty-four patients were included.

RESULTS

Infants with hypertension showed altered LV diastolic function with prolonged tissue Doppler imaging-derived isovolumic relaxation time (54.2 ± 5.1 vs 42.9 ± 8.2, P < .001), lower E:A, and higher E:e'. Indices of left heart volume/pressure loading (left atrium:aorta and LV end-diastolic volume [6.1 ± 2 vs 4.2 ± 1.2, P < .001]) were also higher in the hypertensive group. Finally, infants in the hypertensive group had higher pulmonary vascular resistance index (4.42 ± 1.1 vs 3.69 ± 0.8, P = .004).

CONCLUSIONS

We conclude that extremely preterm infants with BPD who develop systemic hypertension are at risk of abnormal LV diastolic dysfunction. Increased pulmonary vascular resistance index in the hypertensive group may relate to pulmonary venous hypertension secondary to LV dysfunction. This is an important consideration in this cohort when selecting the physiologically most appropriate treatment.

Longitudinal Strain vs. Conventional Echocardiographic Parameters in the First Week of Life in Healthy Term Newborns

The first week of life is characterized by substantial alterations in hemodynamic conditions. Changes in myocardial contractility will reflect these changes. We aimed to assess right and left ventricular function on the third and seventh days of life in 50 healthy term newborns. To assess myocardial function, we used speckle tracking echocardiography. Pulsed-wave tissue Doppler imaging, M-mode, Doppler and pulsed-wave Doppler were also used to assess ventricular function. We found a significant increase in both right and left longitudinal strain and an increase in systolic and diastolic tissue Doppler velocities, whereas most other parameters remained unchanged. At both time points, the measured parameters were significantly greater for the right ventricle, but the changes with time were similar for both ventricles. We also found an increase in right ventricular outflow tract acceleration time as an indirect sign of decreasing pulmonary vascular resistance and an increase in systolic blood pressure, pointing to increasing systemic vascular resistance. Together with a decreasing proportion of patients with patent ductus arteriosus, the estimated left ventricular cardiac output decreased and right ventricular cardiac output increased but not to a statistically significant degree. In conclusion, the results of our study show how different echocardiographic techniques capture hemodynamic changes and changes in myocardial contractility and compliance. Both longitudinal strain and tissue Doppler imaging parameters seem to offer greater sensitivity in comparison with conventional echocardiographic parameters.

Assessment of Myocardial Function in Infants of Mothers with Gestational Diabetes Mellitus Using Deformation Imaging over the First Year of Age

OBJECTIVE

To assess serial myocardial performance and pulmonary vascular resistance (PVR) in infants of mothers with gestational diabetes mellitus (GDM) over the first year of life.

STUDY DESIGN

This was a prospective, observational study. Echocardiography was performed at birth, 6 months, and 1 year of age. Pulmonary artery acceleration time and left ventricular (LV) eccentricity index provided surrogate measurements of PVR. Biventricular function was assessed by tissue Doppler imaging and deformation analysis.

RESULTS

Fifty infants of mothers with GDM were compared with 50 controls with no difference in gestation (38.9 ± 0.8 weeks vs 39.3 ± 0.9 weeks; P = .05) or birthweight (3.55 ± 0.49 kg vs 3.56 ± 0.41 kg; P = .95). At 1 year of age, the pulmonary artery acceleration time was lower (70 ± 11 vs 79 ± 10; P = .01) in the GDM group. LV global longitudinal strain (24.7 ± 1.9 vs 28.8 ± 1.8 %; P < .01), LV systolic strain rate (1.8 ± 0.2 vs 2.1 ± 0.3 1/s; P < .01), and RV free wall strain (31.1 ± 4.8 vs 34.6 ± 3.9 %; P < .01) were lower in the GDM cohort at 1 year of age (all P values adjusted for gestation, mode of delivery, and maternal body mass index).

CONCLUSIONS

Our findings demonstrate higher indices of PVR and lower biventricular function in infants of mothers with GDM compared with controls at each time point assessed in this study over the first year of life.

E-Health: A Game Changer in Fetal and Neonatal Cardiology?

Technological advancements have greatly impacted the healthcare industry, including the integration of e-health in pediatric cardiology. The use of telemedicine, mobile health applications, and electronic health records have demonstrated a significant potential to improve patient outcomes, reduce healthcare costs, and enhance the quality of care. Telemedicine provides a useful tool for remote clinics, follow-up visits, and monitoring for infants with congenital heart disease, while mobile health applications enhance patient and parents' education, medication compliance, and in some instances, remote monitoring of vital signs. Despite the benefits of e-health, there are potential limitations and challenges, such as issues related to availability, cost-effectiveness, data privacy and security, and the potential ethical, legal, and social implications of e-health interventions. In this review, we aim to highlight the current application and perspectives of e-health in the field of fetal and neonatal cardiology, including expert parents' opinions.

Heart function by M-mode and tissue Doppler in the early neonatal period in neonates with fetal growth restriction

BACKGROUND

Fetal growth restricted (FGR) neonates have increased risk of circulatory compromise due to failure of normal transition of circulation after birth.

AIM

Echocardiographic assessment of heart function in FGR neonates first three days after birth.

STUDY DESIGN

Prospective observational study.

SUBJECTS

FGR- and non-FGR neonates.

OUTCOME MEASURES

M-mode excursions and pulsed-wave tissue Doppler velocities normalised for heart size and E/e' of the atrioventricular plane day one, two and three after birth.

RESULTS

Compared with controls (non-FGR of comparable gestational age, n = 41), late-FGR (gestational age ≥ 32 weeks, n = 21) exhibited higher septal excursion (15.9 (0.6) vs. 14.0 (0.4) %, p = 0.021) (mean (SEM)) and left E/e' (17.3 (1.9) vs.11.5 (1.3), p = 0.019). Relative to day three, indexes on day one were higher for left excursion (21 (6) % higher on day one, p = 0.002), right excursion (12 (5) %, p = 0.025), left e' (15 (7) %, p = 0.049), right a' (18 (6) %, p = 0.001), left E/e' (25 (10) %, p = 0.015) and right E/e' (17 (7) %, p = 0.013), whereas no index changed from day two to day three. Late-FGR had no impact on changes from day one and two to day three. No measurements differed between early-FGR (n = 7) and late-FGR.

CONCLUSIONS

FGR impacted neonatal heart function the early transitional days after birth. Late-FGR hearts had increased septal contraction and reduced left diastolic function compared with controls. The dynamic changes in heart function between first three days were most evident in lateral walls, with similar pattern in late-FGR and non-FGR. Early-FGR and late-FGR exhibited similar heart function.

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.

Assessment of myocardial function in late preterm and term infants with transient tachypnea of the newborn using tissue Doppler imaging - a pilot observational study

The aim of this study was to compare conventional and tissue Doppler echocardiography parameters between transient tachypnea of the newborn (TTN) and healthy control infants. This cross sectional pilot observational study was conducted in a level 3 neonatal care unit of India. Consecutively born late preterm and term infants (LPTI) with TTN were eligible for enrollment. Control group was selected from healthy LPTI. Conventional and tissue Doppler (myocardial velocities, myocardial performance index (MPI)) echocardiography was done within first 12 h (D1) and 48-72 h (D3) of life. Conventional echocardiography parameters were fractional shortening (FS), ejection fraction (EF), ventricular output, E/A ratio, fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery systolic pressure (PASP), and pulmonary artery acceleration to ejection time ratio (PATET). Baseline characteristics and echocardiography images were compared between TTN and control groups. Out of 60 infants enrolled, 34 from TTN and 20 from control group were finally analyzed. Mean (SD) gestational age and birth weight of the study population was 36^6/7(1.8) weeks and 2398(376) g respectively. Left ventricular (LV) parameters were similar between both groups. On D1, right ventricular (RV)e' was smaller (6.42(1) cm/s vs. 7.68(1.68) cm/s, p 0.022), and E/e' (7.79(1.51) vs. 6.08(2.59), p 0.037) was larger in TTN group, indicating RV diastolic dysfunction. RV MPI (0.61(0.11) vs. 0.44(0.12), p < 0.001) was also larger, signifying RV global myocardial dysfunction. Similar findings were observed on D3. PATET was lower in TTN group on both D1 (0.34 (0.05) vs. 0.42 (0.05), p < 0.001) and D3 (0.38 (0.05) vs. 0.43 (0.02), p 0.004) suggesting persistently raised pulmonary arterial pressure, although only 2 infants developed pulmonary hypertension identified by standard echocardiography.   Conclusion: Myocardial tissue Doppler imaging of TTN infants revealed occult right ventricular diastolic dysfunction secondary to persistently raised pulmonary arterial pressure. What is Known: •Transient tachypnea of the newborn may be associated with pulmonary arterial hypertension. What is New: •Tissue Doppler imaging in infants with transient tachypnea of the newborn revealed occult right ventricular diastolic dysfunction secondary to raised pulmonary arterial pressure, not detected by standard echocardiography.

Echocardiography parameters used in identifying right ventricle dysfunction in preterm infants with early bronchopulmonary dysplasia: A scoping review

Background

Bronchopulmonary Dysplasia (BPD) is a chronic condition that affects preterm infants and is associated with long-term complications. Haemodynamic effects of BPD can lead to right ventricular (RV) dysfunction.

Objective

To synthesise and map the evidence of echo parameters used in identifying RV dysfunction in the first two weeks-after-birth (WAB) of preterm infants with early BPD.

Information Sources

This scoping review included the databases: Medline, CINAHL, PubMed, EMBASE, Scopus, ProQuest, Web of Science, Cochrane Library, JBI Evidence-Based Practise and Gray Literature.

Search Strategy

The search utilised Boolean operators and descriptors registered in Medical Subject Headings.

Inclusion and exclusion criteria

Included were studies utilising echo parameters to examine RV function in preterm infants with early BPD in the first two WAB.

Synthesis of results

The results are presented as a map of the extracted findings in a tabular format with a narrative summary.

Results

Eight studies were included. Differences were observed in the number and timing of echo scans performed in the first two WAB and the variations in the echo parameters used to compare preterm infants with and without early BPD. Only echo scans performed at the end of the first WAB, demonstrated significant differences in the echo parameters measurements between preterm infants with and without BPD. Studies using RV Myocardial Performance Index (MPI) to identify RV-dysfunction associated with early BPD demonstrated similar findings. The Pulsed-Wave Doppler technique identified differences in RV-MPI between preterm infants with and without BPD, while Tissue-Doppler-Imaging did not demonstrate similar results. Speckle tracking can measure strain (S) and strain rate (SR) and diagnose RV-dysfunction. However, the findings of studies that utilised speckle tracking varied. Finally, two of the included studies added blood tests to their diagnostic model of early BPD, which was able to demonstrate significant differences in blood test results between BPD-affected and control preterm infants.

Conclusion

BPD could adversely affect the myocardium function of the RV; these negative influences can be captured in the first two WAB. However, there are still knowledge gaps regarding the appropriate number, timing and the most suitable echo parameters to assess RV function.

A scoping review of echocardiographic and lung ultrasound biomarkers of bronchopulmonary dysplasia in preterm infants

Despite recent improvements in neonatal care, moderate to severe bronchopulmonary dysplasia (BPD) is still associated with high mortality and with an increased risk of developing pulmonary hypertension (PH). This scoping review provides an updated overview of echocardiographic and lung ultrasound biomarkers associated with BPD and PH, and the parameters that may prognosticate their development and severity, which could be clinically helpful to undertake preventive strategies. A literature search for published clinical studies was conducted in PubMed using MeSH terms, free-text words, and their combinations obtained through appropriate Boolean operators. It was found that the echocardiography biomarkers for BPD, and especially those assessing right ventricular function, are reflective of the high pulmonary vascular resistance and PH, indicating a strong interplay between heart and lung pathophysiology; however, early assessment (e.g., during the first 1-2 weeks of life) may not successfully predict later BPD development. Lung ultrasound indicating poor lung aeration at day 7 after birth has been reported to be highly predictive of later development of BPD at 36 weeks' postmenstrual age. Evidence of PH in BPD infants increases risk of mortality and long-term PH; hence, routine PH surveillance in all at risk preterm infants at 36 weeks, including an echocardiographic assessment, may provide useful information. Progress has been made in identifying the echocardiographic parameters on day 7 and 14 to predict later development of pulmonary hypertension. More studies on sonographic markers, and especially on echocardiographic parameters, are needed for the validation of the currently proposed parameters and the timing of assessment before recommendations can be made for the routine clinical practice.

The use of milrinone in neonates with persistent pulmonary hypertension of the newborn - a randomised controlled trial pilot study (MINT 1)

OBJECTIVE

To assess the impact of milrinone administration on time spent on nitric oxide (iNO) in infants with acute pulmonary hypertension (aPH). We hypothesized that intravenous milrinone used in conjunction with iNO would reduce the time on iNO therapy and the time spent on invasive ventilation in infants ≥34 weeks gestation with a diagnosis of aPH. We aimed to assess the practicality of instituting the protocol and contributing to a sample size calculation for a definitive multicentre study.

STUDY DESIGN

This was a multicentre, randomized, double-blind, two arm pilot study, with a balanced (1:1) allocation. Infants with a gestation ≥34 weeks and a birth weight ≥2000 grams aPH, an oxygenation index of ≥10, and commenced on iNO were eligible. Participants on iNO were assigned to either a milrinone infusion (intervention) or a normal saline infusion (placebo) for up to 35 h. The primary outcome was time on iNO and feasibility of conducting the protocol.

RESULTS

The trial was terminated early after 4 years of enrollment due to poor recruitment. Four infants were allocated to the intervention arm and 5 to the placebo arm. The groups were well matched for baseline variables. No differences were seen in any of the primary or secondary outcomes.

CONCLUSION

Conducting an interventional trial in the setting of acute pulmonary hypertension in infants is not feasible using our current approach. Future studies in this area require alternative trial design to improve recruitment as this topic remains understudied in the neonatal field.

TRIAL REGISTRATION

www.isrctn.com ; ISRCTN:12949496; EudraCT Number:2014-002988-16.

Exploring right ventricular function applicability in a prediction model to identify preterm infants with early bronchopulmonary dysplasia (REPORT-BPD study): a mixed-methods observational cohort feasibility study protocol

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic disease that affects the immature lungs of preterm infants. Infants born before 32 weeks of gestation are at a greater risk of developing BPD due to the need for respiratory support with higher oxygen requirement. Pulmonary vascular remodelling in early BPD can impose an additional burden on the right ventricle (RV) and RV dysfunction. This protocol outlines the study design and aims to formulate a prediction model to identify early BPD through the data generated from echo scans analysis.

METHODS

The mixed-methods observational cohort feasibility study, which comprises three work-packages (WPs), will be conducted at the regional neonatal unit, University Hospital Plymouth, Plymouth, UK. WP-I will recruit 40 preterm infants; each participant will have two heart scans performed in the first ten days after birth (DABs). WP-II will collect the documentation of the participating preterm infants' parents in the study neonatal unit diaries in the first 10 DABs. WP-III will involve semi-structured interviews of 10-15 parents of participating preterm infants and 10-15 health professionals who participated in WP-I. The study recruitment will be conducted over 18-months. The start date is 01 June 2022. WP-I and WP-II recruitment will occur during this period, while WP-III recruitment will occur during the second half. The results are expected to be submitted for publication by mid-2024.

DISCUSSION

This paper outlines the study design. If the study successfully identifies the most sensitive echo parameter in recognising the RV dysfunction associated with early BPD, it will be an important finding in constructing an early BPD prediction model.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier is NCT05235399.

Computational Analysis of Cardiac Contractile Function

PURPOSE OF REVIEW

Heart failure results in the high incidence and mortality all over the world. Mechanical properties of myocardium are critical determinants of cardiac function, with regional variations in myocardial contractility demonstrated within infarcted ventricles. Quantitative assessment of cardiac contractile function is therefore critical to identify myocardial infarction for the early diagnosis and therapeutic intervention.

RECENT FINDINGS

Current advancement of cardiac functional assessments is in pace with the development of imaging techniques. The methods tailored to advanced imaging have been widely used in cardiac magnetic resonance, echocardiography, and optical microscopy. In this review, we introduce fundamental concepts and applications of representative methods for each imaging modality used in both fundamental research and clinical investigations. All these methods have been designed or developed to quantify time-dependent 2-dimensional (2D) or 3D cardiac mechanics, holding great potential to unravel global or regional myocardial deformation and contractile function from end-systole to end-diastole. Computational methods to assess cardiac contractile function provide a quantitative insight into the analysis of myocardial mechanics during cardiac development, injury, and remodeling.

Assessment of Indicators of Left Ventricular Performance Obtained by Tissue Doppler Imaging in Prematurely Born Neonates

Introduction: Tissue Doppler imaging techniques (pulsed-wave TDI (pwTDI) and color-coded TDI (cTDI)) allow for the assessment of myocardial performance during the cardiac cycle. The application of such techniques in neonatology is sporadic and poorly studied. Objective: The objective of the present study was to determine average values of pwTDI indicators of left ventricular performance (maximum systolic velocity of the mitral annulus (s’), maximum velocity in early diastole (e’) and maximum velocity in late diastole (a’)) and to examine their dynamics in prematurely born newborns in the first week of life. Methods: Prematurely born newborns of postnatal age up to 7 days were divided by gestational age into Group1 (<28 weeks) and Group 2 (≥28 weeks). Standard pwTDI parameters (s’, e’ and a’) were measured, compared between the groups and correlated with gestational and postnatal age, as well as application of respiratory support. Results: Fifty subjects were included (Group 1: 24; Group 2: 26). Average values of parameters s’, e’ and a’ were: Group 1: 4.06 ± 0.78 cm/s, 3.71 ± 0.40 cm/s and 3.98 ± 1.06 cm/s, respectively; Group 2: 4.18 ± 1.22 cm/s, 4.68 ± 1.04 cm/s and 4.12 ± 0.94 cm/s, respectively. Values of parameter e’ differed significantly between groups (p = 0.001) and strongly correlated with gestational age (p = 0, Pearson’s R = 0.88). There was no significant difference between groups for parameters s’ and a’ (p = 0.42 and 0.31, respectively). The values of s’, e’ and a’ did not differ between patients with an without respiratory support. Conclusion: Parameter e’ depends on gestational age, whereas parameters s’ and a’ are independent of gestational age. pwTDI indicators do not change during the first week of life, nor are all robust to hemodynamic circumstances caused by invasive/non-invasive respiratory support.

Right Ventricular Function in Neonates During Early Postnatal Period: A Prospective Observational Study

Previous echocardiographic studies were mainly focused on preterm infants and early fetal-to-neonatal transition period, whereas little is known about changes in the parameters of the right ventricular (RV) function after 72 h of life. Our aim was to quantitatively characterize potential changes in RV function by echocardiography in healthy term newborns between the third and the seventh day of life. We conducted a prospective observational study in 35 full-term newborns, in whom we performed echocardiographic examinations on the third and the seventh day of life. We assessed RV function, output and afterload and found a significant increase in all tissue Doppler velocities as well as in RV longitudinal strain, a higher mean RV outflow tract velocity time integral and lower myocardial performance index (MPI'), whereas the tricuspid annular plane systolic excursion, RV filling pattern, and RV outflow tract acceleration time were not significantly different between the third and the seventh day of life. Conclusions: Increased RV systolic and diastolic myocardial velocities, cardiac output and longitudinal deformation and decreased RV MPI' between the third and the seventh day of life point to a reduction of RV afterload and adaptive myocardial maturation in term newborns during this period. Moreover, PW-TDI and 2D speckle-tracking echocardiography seem to be more sensitive for evaluating RV function in comparison with M-mode echocardiography and pulsed-wave Doppler analysis of RV filling.

Serial Assessment of Cardiac Function and Pulmonary Hemodynamics in Infants with Down Syndrome

BACKGROUND

There is a dearth of longitudinal data describing the evolution of cardiopulmonary haemodynamics in infants with Down Syndrome (DS) beyond infancy. We hypothesized that babies with DS, independent of the presence of congenital heart disease (CHD), demonstrate biventricular systolic and diastolic impairment and sustained elevation of pulmonary pressures compared to controls over the first two years of age.

METHODS

This was a prospective observational cohort study of 70 infants with DS (48 with CHD and 22 without CHD) and 60 controls carried out in three tertiary neonatal intensive care units in Dublin, Ireland. Infants with DS with and without CHD and non-DS controls underwent serial echocardiograms at birth, 6 months, 1 year and 2 years of age to assess biventricular systolic and diastolic function using deformation analysis. Pulmonary vascular resistance (PVR) was assessed using pulmonary artery acceleration time (PAAT) and left ventricular (LV) eccentricity index.

RESULTS

Infants with DS exhibited smaller LV (Birth: 27±4 vs. 31±2 mm, p<0.01; 2 years: 43±5 vs. 48±4 mm, p<0.01) and RV (Birth: 28±3 vs. 31±2 mm, p<0.01; 2 years: 40±4 vs. 44±3 mm, p<0.01) lengths and lower LV (Birth: -19±3 vs. -22±2 %, p<0.01; 2 years: -24±2 vs. -26±2 %, p<0.01) and RV (Birth: -19±4 vs. -22±3 %, p<0.01; 2 years: -29±6 vs. -33±4 %, p<0.01) systolic strain over the two year period. PAAT was lower in the DS group throughout the study period (Birth: 44±10 vs. 62±14 ms, p<0.01; 2 years 71±12 vs. 83±11 ms, p<0.01). No differences were observed between DS infants with and without CHD (all p >0.05).

CONCLUSIONS

Infants with DS exhibit impaired maturational changes in myocardial function and PVR. Such novel findings provide valuable insights into the pathophysiology affecting cardiorespiratory morbidity in this population.

Peri-operative myocardial performance in infants with Down syndrome undergoing CHD repair

BACKGROUND

We aimed to characterise the impact of Down syndrome on myocardial performance and loading conditions in infants with Down syndrome and CHD over the peri-operative period by comparing them with infants matched for cardiac lesion with a normal microarray.

METHODS

Left ventricular global longitudinal strain, right ventricular free wall longitudinal strain, left ventricular end-systolic wall stress, and right ventricular systolic pressure were measured in the two groups over the peri-operative period.

RESULTS

Fifty-five infants had a diagnosis of Down syndrome and these were compared with 29 control infants. Left ventricular global longitudinal strain decreased in both groups post-operatively with the Down syndrome group demonstrating some recovery pre-discharge (18 ± 3 versus 16 ± 3 %, p = 0.01). Right ventricular longitudinal strain significantly decreased in both groups post-operatively with the control group demonstrating better recovery by hospital discharge (14 ± 4 versus 18 ± 6 %, p < 0.01). End-systolic wall stress was lower and right ventricular systolic pressure was higher in the Down syndrome group throughout the study period (all p < 0.05). Down syndrome was an independent predictor of the duration of ventilation, post-operative use of inotropes, and intensive care stay. Right ventricular longitudinal strain was an independent predictor of duration of intensive care stay.

CONCLUSION

This study demonstrates the difference between the two groups in relation to left and right ventricular function, particularly prior to discharge, and outlines the additional impact a diagnosis of Down syndrome has on myocardial performance during the peri-operative period.

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.

Mitral valve Doppler for cardiac output assessment in preterm neonates

INTRODUCTION

Cardiac output (CO) assessment in neonates is commonly done by echocardiography. It is unclear which is the best site to measure the left ventricular (LV) outflow tract for CO assessment (the aortic valve [AV] aortic sinus [AS] or the sinotubular junction [STJ]). In the normal heart, the blood flow entering the LV equals the blood ejected from it. Therefore, measuring the blood flow into the LV through the mitral valve (MV) is an alternative way to measure CO.

METHODS

In stable preterm infants the MV CO was compared with the right ventricular (RV) CO and the three ways to measure LV CO, in 30 stable preterm neonates. Interobserver variability for MV CO was established.

RESULTS

In the 30 neonates studied, MV CO was best correlated and had a minimal bias to the RV CO and LV CO measured at the STJ. Left ventricular CO measured at the AV and AS had significant bias relative to RV CO and MV CO. MV CO inter-observer variability was similar to other echocardiographic CO assessment methods.

CONCLUSION

MV CO may be used as an alternative way to assess CO. The STJ may be the optimal site to measure LV outflow tract.

Diastolic Dysfunction in Neonates With Hypoxic-Ischemic Encephalopathy During Therapeutic Hypothermia: A Tissue Doppler Study

Diastolic dysfunction often complicates myocardial ischemia with increased mortality rates. However, less is known about diastolic function after perinatal asphyxia in neonates with hypoxic-ischemic encephalopathy (HIE) during therapeutic hypothermia (TH) and rewarming.

AIM

The aim of this study was to assess diastolic function with tissue Doppler imaging (TDI) in neonates with moderate-severe HIE during TH and rewarming.

METHOD

Newborns at >36 weeks' gestation with moderate-severe HIE treated with TH were evaluated with targeted neonatal echocardiography (TNE), including TDI, within 24 h of TH initiation (T1), at 48-72 h of treatment (T2), and after rewarming (T3). These retrospective data were collected and compared with a control group of healthy babies at >36 weeks' gestation that was prospectively evaluated following the same protocol.

RESULTS

A total of 21 patients with HIE + TH and 15 controls were included in the study. Myocardial relaxation before the onset of biventricular filling was prolonged in the HIE + TH group during TH with significantly longer isovolumic relaxation time (IVRT') in the left ventricle (LV), the septum, and the right ventricle (RV). This was associated with slower RV early diastolic velocity (e') and prolonged filling on T1. Total isovolumic time (t-IVT; isovolumic contraction time [IVCT'] + IVRT') and myocardial performance index (MPI') were globally increased in asphyxiated neonates. All these differences persisted after correction for heart rate (HR) and normalized after rewarming. TDI parameters assessing late diastole (a' velocity or e'/a' and E/e' ratios) did not differ between groups.

CONCLUSION

TDI evaluation in our study demonstrated a pattern of early diastolic dysfunction during TH that normalized after rewarming, whereas late diastole seemed to be preserved. Our data also suggest a possible involvement of impaired twist/untwist motion and dyssynchrony. More studies are needed to investigate the impact and therapeutic implication of diastolic dysfunction in these babies, as well as to clarify the role of TH in these findings.

Neonatologist Performed Echocardiography for Evaluating the Newborn Infant

The interest in the use of cardiac ultrasound for hemodynamic evaluation in neonates has increased in the last decades. Several overlapping terms exists, and a non-comprehensive list includes point-of-care ultrasound, clinician-performed ultrasound, focused cardiac ultrasound, targeted neonatal echocardiography, and neonatologist performed echocardiography. This review will use the term neonatologist performed echocardiography. Neonatologist performed echocardiography is primarily echocardiography to obtain snapshots of hemodynamics and heart function, usually as repeated exams during intensive care. It provides the neonatologist with in-depth information on the hemodynamics not available by blood pressure, pulse oximetry, capillary refill time, and various blood tests. The review provides a brief overview of some relevant methods for assessment of hemodynamics and heart function. It does not discuss training, implementation, accreditation, and certification nor in-depth technical aspects and detailed use of neonatologist performed echocardiography. If the information obtainable by neonatologist performed echocardiography had been accessible easily (e.g., via a sensor put on the neonate similarly to a pulse oximeter), neonatologist performed echocardiography would have been more widely used. Acquiring skills for neonatologist performed echocardiography take time and resources. Future developments probably include a stronger focus on education, training, and certification. It is likely that echocardiographic methods will evolve further, probably involving establishing new indexes and methods and implementing artificial intelligence in the analyses procedure to improve accuracy and workflow. It is important to acknowledge that neonatologist performed echocardiography is not a therapeutic intervention; it is a diagnostic tool providing additional information.

Evaluating Left Ventricular Systolic Synchronicity with Real-Time 3D Echocardiography in Newborns

Knowing the normal values of left ventricular (LV) systolic synchronicity in the early neonatal period is very important for understanding myocardial function. This retrospective study analyzed data of 105 newborns who were examined using real-time 3-dimensional echocardiography (RT3DE). The time to the point of minimal regional systolic volume (Tmsv) was measured from volume-time curves in each segment. Standard deviation (SD) and maximal difference (Dif) of Tmsv were calculated from 16 (6 basal/6 mid/4 apical), 12 (6 basal/6 mid), and 6 (basal) LV segments with the corresponding parameters adjusted for the R-R interval. Influences of age, sex, gestational age, birth weight, and heart rate on parameters were explored. Data showed no significant difference among Tmsv-16-SD, Tmsv-12-SD, and Tmsv-6-SD. A strong correlation was found between Tmsv-6-SD and Tmsv-6-Dif (r = 0.83, P < 0.001), Tmsv-12-SD and Tmsv-6-SD (r = 0.77, P < 0.001), and Tmsv-12-Dif and Tmsv-6-Dif (r = 0.76, P < 0.001) and a moderate correlation was found between Tmsv-16-SD and Tmsv-16-Dif (r = 0.66, P < 0.001), Tmsv-6-SD and Tmsv-12-Dif (r = 0.62, P < 0.001), and Tmsv-12-SD and Tmsv-6-Dif (r = 0.61, P < 0.001). Heart rate correlated negatively with Tmsv (r = - 0.03 to - 0.11, P < 0.004-0.000), but had no effect on parameters adjusted for %R-R. Age, sex, gestational age, and birth weight did not affect any of these parameters. Tmsv-Dif and Tmsv-SD measured from 16 segments using RT3DE are useful as possible parameters for evaluating LV systolic synchronicity in normal newborns.

Pulmonary hypertension in a neonatologist-performed echocardiographic follow-up of bronchopulmonary dysplasia

Neonatologist-performed echocardiography (NPE) is an established tool for bedside hemodynamic evaluation, including pulmonary hypertension (PH). PH may complicate bronchopulmonary dysplasia (BPD) course. Aims of this retrospective study were to assess the feasibility of NPE follow-up of infants with BPD and to describe the course of PH of infants with moderate/severe BPD. Preterm infants <32 gestational weeks or birthweight ≤1500 g with moderate/severe BPD underwent NPE follow-up, from 36 weeks postmenstrual age up to 8 months postnatal age. Twenty-three preemies were included (birth weight 840 (213) g, gestational age 26.8 (2.3) weeks); 12/23 developed mild PH, 2/12 after discharge. PH resolved at 8.9 (3.9) months. Clinical and echocardiographic variables did not differ between infants with and without PH, except pulmonary artery acceleration time (PAAT) and PAAT/right ventricle ejection time (RVET) ratio (PAAT: 36 weeks, 68.9 (11.9) vs 52.0 (19.1), p = 0.0443; 6 months: 83.9 (38.9) vs 74.8 (16.9), p = 0.0372). No deaths or admissions for PH were reported. Neonatologist's Image Quality Assessment score attributed by the cardiologist assumed as gold standard was adequate or optimal (9.5/14 total score); inter-rater agreement was excellent (ICC 0.974).Conclusions: NPE follow-up seems to be feasible and safe in both intensive care and outpatient clinic. Mild PH is frequently detected in moderate/severe BPD, with good prognosis. What is Known: • Preterm infants with bronchopulmonary dysplasia (BPD) may develop pulmonary hypertension (PH) and have a late diagnosis. • Neonatologist-performed echocardiography (NPE) is an established tool for bedside hemodynamic evaluation of the neonate. What is New: • To our knowledge this is the first study of NPE follow-up of moderate/severe BPD, describing the course of mild PH from diagnosis to its resolution. • NPE follow-up of BPD seems to be safe and practicable, in both intensive care and outpatient clinic, as long as neonatologists maintain a sound collaboration with pediatric cardiologists.

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.

Myocardial performance index in term appropriate and small for gestational age neonates - a cross sectional study

BACKGROUND

It is known that small for gestational age (SGA) babies may be at an increased risk of cardiovascular diseases during adulthood. There is paucity of literature regarding comparative cardiac functions of SGA and appropriate for gestational age (AGA) babies in neonatal period. The present study was conceived to compare the cardiac function of term small and appropriate for gestational age (AGA) babies through a relatively novel echocardiographic index in early neonatal period.

OBJECTIVES

To compare values of myocardial performance index (MPI) index (MPI = IVCT + IVRT/ET) at 48-72 hours of age among AGA and SGA babies.

METHODS

Morphological and anthropometric assessment of serially born term babies was done at time of birth to recruit hundred each of AGA and SGA babies. Tissue Doppler Imaging (TDI) was done between 48-72 hours for each enrolled baby to assess both right and left ventricle MPI in each group.

RESULTS

Mean±SD values for right ventricular MPI in AGA and SGA groups were 0.268 + 0.007 and 0.30 + 0.026 respectively (p < 0.001). Mean±SD values for left ventricular MPI in AGA and SGA groups were 0.25 + 0.012 and 0.30 + 0.017 respectively (p < 0.001). There was significant negative correlation between MPI values for either ventricles and the birth weight (spearmen's rho of -0.66) (p < 0.001). Mean±SD values for LVET in AGA and SGA group were 0.304 + 0.026 and 0.266 + 0.032 respectively (p < 0.001).

CONCLUSION

MPI had a higher absolute value in the SGA babies as compared to AGA babies. These observations point towards suboptimal cardiac performance among SGA babies as compared to AGA babies on the basis of myocardial performance index.

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).

Comparison of left ventricular rotational mechanics between term and extremely premature infants over the first week of age

Objective

Left ventricle (LV) rotational mechanics is an emerging tool to characterise LV function, but warrants further evaluation in neonates. The aim of this study was to compare LV rotational mechanics between term and extremely preterm babies over the first week of age.

Methods

In this prospective study, we serially assessed LV rotational parameters in 50 term infants and compared them with a historical dataset of 50 preterm infants born <29 weeks gestation. LV basal and apical rotation, LV twist, LV twist/untwist rate and torsion were derived using two-dimensional speckle tracking echocardiography at three time points over the first week of age.

Results

There was no change in LV twist, LV torsion, basal rotation or apical rotation in term infants over the study period (all p>0.05). LV twist and torsion were higher in preterm infants, and increased over time. In preterm infants, basal rotation evolved from anticlockwise to clockwise rotation. Apical rotation remained anticlockwise in both groups (all p>0.05). LV twist rate (LVTR) and untwist rate was higher in preterm infants and increased over the three time points (all p>0.05). There was a strong positive correlation between LV torsion and LV untwist rate (LVUTR) in the entire cohort during the third scan.

Conclusion

Term infants exhibit minimal LV twist which remains unchanged over the first week of age. This is in contrast to premature infants who demonstrate increasing indices of twist, torsion, LVTR and LVUTR over the first week, likely as a compensatory mechanism for reduced LV compliance.

Longitudinal assessment of cardiac function in infants with Down's syndrome using novel echocardiography techniques - project protocol

Background: Down’s syndrome (DS) is the most common chromosomal abnormality globally. Ireland has one of the highest rates of DS in the western world with an incidence of 1:444 live births. Congenital heart disease (CHD) and pulmonary hypertension (PH) are the commonest morbidities affecting the cardiovascular system in DS. PH is associated with significant morbidity and an increase risk of mortality. The impact of the diagnosis of DS, the presence of CHD and the associated PH on myocardial function during transition and over the first 2 years of age in this population is not well defined and warrants further study. In particular, serial measurements of pulmonary pressures in this population over the first week of age are lacking. This study aims to characterise myocardial function and pulmonary haemodynamics in infants with Down syndrome during the transitional period (over the first week of age) and throughout the first two years of age.

Methods: A prospective, observational study utilising novel echocardiography techniques to assess myocardial function and pulmonary haemodynamics over the first two years of age in infants with Down Syndrome. A population of healthy infants without CHD or a diagnosis of DS will be recruited as controls. This study will be conducted across the three Dublin maternity units.

Discussion: In total, 70 babies with DS have been enrolled into this study with 292 echocardiograms performed to date. Further evaluation of cardiac performance in DS infants with and without CHD may yield more insight into the pathophysiology of cardiac dysfunction and pulmonary hypertension that are recognised features in these patients. This could aid in our ability to monitor and treat patients, as well as improve our ability to predict outcomes.

Assessment of neonatal perfusion

Disorders of perfusion in newborn infants are frequently observed in neonatal intensive care units. The current assessment practices are primarily based on clinical signs. Significant technologic advances have opened new avenues for continuous assessment at the bedside. Combining these devices with functional echocardiography provides an in-depth understanding of perfusion and allows targeting therapy to the pathophysiology rather than monitoring and targeting blood pressure. This change in approach is guided by the fact that perfusion disorders can result from a number of causes and a single management approach might do more harm than good. This approach has the potential to improve long term outcomes but needs to be tested in well-designed trials.

Hypothermia and Cardiovascular Instability

Severely asphyxiated neonates have acute heart failure as part of their multiorgan dysfunction syndrome during the first days of life. Supporting the cardiovascular system during this phase is part of contemporary treatment and regarded as vital for limiting the neurodevelopmental injury. The decision to treat cardiovascular instability should be based on evaluation of end-organ function. Neonatologist-performed echocardiography in combination with other diagnostic modalities enables comprehensive real-time assessment. This review discusses associations between hemodynamics and adverse outcome, modalities for evaluating the hemodynamic state of the infant, and therapeutic approaches during intensive care.

The Future of Cardiac Ultrasound in the Neonatal Intensive Care Unit

Cardiac ultrasound is increasingly used to guide hemodynamic decision making in the neonatal intensive care unit (NICU). This article focuses on likely future progress in training, accreditation, digital connectivity, miniaturization, and modality development. Many documents have been published internationally to guide cardiac ultrasound training, accreditation, and implementation in the NICU, but challenges remain in providing assessments of hemodynamic status without risking missed structural diagnoses. Advances in simulation training and digital connectivity provide an opportunity to standardize approaches across institutions and continents. Development of machine learning and ultrasound modalities in turn provide huge scope for improving robustness and completeness of assessment.

Neonatal functional echocardiography

PURPOSE OF REVIEW

The role of echocardiography has dramatically changed over the past decade and use of functional echocardiography has become increasingly popular among neonatologists and pediatric intensivists in making clinical decisions in sick infants and children. The purpose of this review is to outline the current capabilities and limitations of functional echocardiography, best practices for its clinical application, and evidence for its utility.

RECENT FINDINGS

Functional echocardiography can provide direct assessment of hemodynamics at bedside and can be used as a modern hemodynamic monitoring tool in the neonatal intensive care unit. It is now being regarded as a useful extension to the clinical examination and other monitoring tools in the critically ill infant. The anatomic, physiological, and hemodynamic information functional echocardiography provides can be used in targeting specific interventions and evaluating response to treatment.

SUMMARY

This review article is focused on an overview of the most common applications of functional neonatal echocardiography also called targeted neonatal echocardiography or neonatologist performed echocardiography. It will review assessment of hemodynamics and cardiac function in neonatal hypotension and shock, suspected patent ductus arteriosus, suspected persistent pulmonary hypertension of the newborn with evaluation of pulmonary artery pressure and assessment of pericardial effusion. It will also emphasize the specific requirements for the practice and training of functional neonatal echocardiography.

Myocardial function in late preterm infants during the transitional period: comprehensive appraisal with deformation mechanics and non-invasive cardiac output monitoring

BACKGROUND

There is a paucity of functional data on mid-to-late preterm infants between 30+0 and 34+6 weeks gestation. We aimed to characterise transitional cardiopulmonary and haemodynamic changes during the first 48 hours in asymptomatic mid-to-late preterm infants.

METHODS

Forty-five healthy preterm newborns (mean ± standard deviation) gestation of 32.7 ± 1.2 weeks) underwent echocardiography on Days 1 and 2. Ventricular mechanics were assessed by speckle tracking-derived deformation, rotational mechanics, tissue Doppler imaging, and right ventricle-focused measures (tricuspid annular plane systolic excursion, fractional area change). Continuous haemodynamics were assessed using the NICOM™ system to obtain left ventricular output, stroke volume, heart rate, and total peripheral resistance by non-invasive cardiac output monitoring.

RESULTS

Right ventricular function increased (all measures p < 0.005) with mostly stable left ventricular performance between Day 1 and Day 2. NICOM-derived left ventricular output [mean 34%, 95% confidence interval 21-47%] and stroke volume [29%, 16-42%] increased with no change in heart rate [5%, -2 to 12%]. There was a rise in mean blood pressure [11%, 1-21%], but a decline in total peripheral resistance [-14%, -25 to -3%].

CONCLUSION

Left ventricular mechanics remained persevered in mid-to-late premature infants, but right ventricular function increased. Non-invasive cardiac output monitoring is feasible in preterm infants with an increase in left ventricular output driven by an improvement in stroke volume during the transitional period.

Propofol Formulation Affects Myocardial Function in Newborn Infants

This study aimed to evaluate the effects of propofol in diluted and undiluted formulations on cardiac function in infants. Infants > 30 days received propofol sedation for central line insertion. Cases were divided into two groups: those who received undiluted 1% propofol (P1%); and those who received a diluted formulation (Pd) of equal volumes propofol 1% and 0.9% NaCl. Echocardiograms were performed pre (t₀)-, immediately post (t₁)-, and 1-h post (t₂) propofol administration. Myocardial deformation was assessed with tissue Doppler imaging (TDI) analysis and peak longitudinal strain (LS). 18 cases were included: nine (50%) P1% and nine (50%) Pd. In the P1% group, TDI velocities and LS were significantly reduced at t₁ and t₂. In the Pd Group, only TDI velocities in the left ventricle were reduced at t₁, but not at t₂. Dilution of propofol may minimize myocardial dysfunction while maintaining adequate sedation in infants. Further comparative studies are needed to investigate the safety and efficacy of this approach.

NT-proBNP as an Early Marker of Diastolic Ventricular Dysfunction in Very-Low-Birth-Weight Infants

The objective is to examine the correlation between plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and tissue Doppler imaging (TDI) echocardiographic parameters in the first 28 days of life in very-low-birth-weight infants (VLBWI). VLBWI admitted to the Neonatal Intensive Care Unit (NICU) at Hospital Puerta del Mar, Spain, from January 2015 to January 2017 were prospectively enrolled. Weekly determination of plasma NT-proBNP (pg/mL), and echocardiograms were done during the first 28 days of life. 101 preterm infants with a mean GA of 28.85 weeks (± 1.85 SD) and mean birth weight of 1152 g (± 247.4 SD) were included. A total of 483 echocardiograms and 139 NT-proBNP determinations were performed. We found a negative correlation between plasma NT-proBNP levels and diastolic velocities: mitral A' (ρ = - 0.15, p = 0.04), mitral E' (ρ = - 0.17, p = 0.02), tricuspid A' (ρ = - 0.20, p = 0.006), tricuspid E' (ρ = - 0.24, p = 0.0009). In the first 24 h of life, NT-proBNP levels were strongly correlated with mitral A' and E' velocities in patients with no patent ductus arteriosus (PDA) (ρ = - 0.75, p = 0.04). In preterm patients, elevated NT-proBNP levels are related to worse diastolic myocardial function. In the first 24 h, this correlation is much stronger in the absence of PDA.

The overlooked left ventricle in persistent pulmonary hypertension of the newborn

Introduction: Persistent pulmonary hypertension of the newborn (PPHN) is a rapidly increasing condition among neonates. It represents failure of adaptation of pulmonary circulation to the extrauterine environment causing severe hypoxemia in affected newborns. Few data have weighed the relationship of ventricular dysfunction in the context of PPHN and the outcome in involved patients. The aim of this paper is to study ventricular functions in newborns with PPHN and to determine whether short-term outcome is closely related or not to ventricular dysfunction occurring in PPHN.Methods: Thirty full-term neonates with PPHN were screened with conventional echocardiography and tissue Doppler imaging (TDI) for the assessment of ventricular functions at the start of treatment for PPHN, demographic data and Arterial blood gazes were performed as well. The echocardiographic data were compared to healthy age-matched controls. The sensitivity and specificity of relevant echocardiographic data to predict the short-term (Day 3) outcome of patients were measured.Results: Patients with PPHN had both left ventricular (LV) and right ventricular (RV) dysfunction when compared to controls, RV Tei (Cases: 0.39 ± 0.1 versus controls: 0.29 ± 0.08, p < .01) LV Tei (Cases: 0.3 ± 0.04 versus controls: 0.25 ± 0.02, p < .01), LV functions were found of greatest prediction of negative outcome in cases with PPHN than RV Tei.Conclusion: The aforementioned findings are sight opening towards the importance of LV dysfunction in PPHN, LV dysfunction might occur in PPHN as a result of RV-LV interactions and the observed involvement might be an important aggravating factor of PPHN.

Postnatal Myocardial Function in Monochorionic Diamniotic Twins with Twin-to-Twin Transfusion Syndrome following Selective Laser Photocoagulation of the Communicating Placental Vessels

BACKGROUND

Monochorionic diamniotic (MCDA) twins are at risk for developing twin-to-twin transfusion syndrome (TTTS) throughout pregnancy. This may lead to myocardial dysfunction in the recipient and/or donor twin that persists beyond delivery. Selective laser photocoagulation of the communicating placental vessels (SLPCV) attempts to mitigate the cardiovascular outcomes. The objective of this study was to characterize early postnatal myocardial performance in MCDA twins with TTTS with and without SLPCV.

METHODS

A prospective study was performed of four MCDA twin groups: (1) uncomplicated MCDA twins, (2) MCDA twins with selective fetal growth restriction, (3) MCDA twins with TTTS following SLPCV (TTTS with SLPCV), and (4) MCDA twins with TTTS who did not undergo SLPCV (TTTS without SLPCV). Fifty-four twin pairs were enrolled: 23 uncomplicated MCDA twin pairs, 15 pairs with selective fetal growth restriction, seven TTTS pairs with SLPCV, and seven TTTS pairs without SLPCV. In each group, twin pairs were divided by birth weight into donor (smaller) and recipient (larger) and compared. Echocardiography was performed on day 1, day 2, and between days 5 and 7 of age, and myocardial performance was characterized by speckle-tracking echocardiography-derived left ventricular and right ventricular longitudinal strain (LS) and systolic strain rate (LSR). Longitudinal strain and longitudinal systolic strain rate are expressed as absolute values.

RESULTS

Compared with all recipient groups, recipient TTTS without SLPCV infants had lower left ventricular LS (16 ± 3% vs 22%-24%, P < .01) and right ventricular LS (15 ± 5% vs 21%-24%, P < .01) on day 1 that persisted throughout the first week of age. Left ventricular LSR (1.7 ± 0.3 vs 2.3 ± 0.3 sec^-1, P < .05) and right ventricular LSR (1.5 ± 0.4 vs 1.7 ± 0.5 sec^-1, P < .05) were both lower in the recipient compared with the donor twin in the TTTS without SLPCV group. LS and LSR measurements were similar among all four donor twin groups.

CONCLUSIONS

Biventricular performance is diminished in recipient MCDA twins with TTTS who are not treated with SLPCV, highlighting the need for close monitoring of their hemodynamic status during the early neonatal period.

Myocardial Function Maturation in Very-Low-Birth-Weight Infants and Development of Bronchopulmonary Dysplasia

Background: Myocardial function in very-low-birth-weight infants (VLBWIs) develops during early postnatal life, but different patterns of temporal evolution that might be related to the development of bronchopulmonary dysplasia (BPD) are not completely understood. Methods: A prospective cohort study including VLBWIs admitted to our NICU from January 2015 to 2017 was conducted. Plasma N-terminal pro B type natriuretic peptide (NTproBNP) levels were measured, and echocardiograms were performed at 24 and 72 h of life and weekly thereafter until 36 weeks of postmenstrual age (PMA). We measured the tricuspid annular plane systolic excursion (TAPSE) by M-mode; the lateral tricuspid E', A', and S' waves; and the myocardial performance index (MPI) by tissue doppler imaging (TDI). The subjects were divided into non-BPD and BPD groups. Results: We included 101 VLBWIs. The TAPSE and E', A', and S' waves increased while MPI-TDI decreased over time. Birth gestational age (GA) and postnatal PMA impacted these parameters, which evolved differently in those who developed BPD compared to those in the non-BPD group. The NTproBNP levels at 14 days of life and different echocardiographic parameters were associated with the development of BPD in different multivariate models. Conclusion: TAPSE and TDI values depend on GA and PMA and follow a different temporal evolution that is related to the later development of BPD. Combined biochemical and echocardiographic biomarkers can help identify which VLBWIs are at higher risk of developing BDP.