Chronological Echocardiographic Changes in Healthy Term Neonates within Postnatal 72 Hours Using Doppler Studies

Early postnatal transitional circulation in fetal growth restricted neonates

BACKGROUND

Fetal growth restriction (FGR) may impact early postnatal transitional circulation.

AIM

Echocardiographic assessment of left ventricular cardiac output, superior vena cava (SVC) and ductus venosus (DV) blood flow in FGR neonates first three days after birth.

STUDY DESIGN

Prospective observational study.

SUBJECTS

FGR and Non-FGR neonates.

OUTCOME MEASURES

Left ventricular cardiac output, SVC and DV blood flow day one, two, and three.

RESULTS

Adjusting for gestational age (GA), birth weight, sex, and twin/singleton, flow measurements were similar between Late-FGR (GA ≥ 32 weeks, n = 23) and Non-FGR (GA ≥ 32 weeks, n = 39). On day three, Late-FGR had significantly lower left ventricular stroke volume (Estimated Marginal Means (Standard Error) 0.99 (0.08) vs 1.22 (0.06) mL/kg, p = 0.027) and higher heart rate (134 (5) vs 119 (4) beats/min, p = 0.032). Left ventricular cardiac output and left ventricular stroke volume decreased significantly from day one to three in both groups; Late-FGR 170 (8) to 149 (8) mL/min/kg, p = 0.007, and 1.34 (0.07) to 1.17 (0.07) mL/kg, p = 0.015, and Non-FGR 161 (6) to 144 (6) mL/min/kg, p = 0.002, and 1.27 (0.06) to 1.16 (0.06) mL/kg, p = 0.021. SVC flow remained unchanged from day one to three in Late-FGR (92 (6) to 83 (6) mL/min/kg, p = 0.161) and decreased significantly in Non-FGR (83 (5) to 71 (5) mL/min/kg, p = 0.021). DV blood flow remained unchanged. No measurements differed between Early-FGR (GA 30+0-31+6 weeks) and Late-FGR.

CONCLUSIONS

Late-FGR had limited impact on left ventricular cardiac output, SVC and DV blood flow in early neonatal period. Most adaptive circulatory changes occurred early during transition.

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.

Hemodynamics in neonates with polycythemia before and after partial exchange transfusion: an observational study

Introduction

The current recommendations for the management of neonatal polycythemia are that partial exchange transfusion (PET) should be performed if the hematocrit is >70% in an asymptomatic neonate, or if the haematocrit is >65% in a symptomatic neonate. The hemodynamic effects of PET for neonatal polycythemia have not been well researched.

Objectives

To evaluate the hemodynamic effects of PET in neonates with polycythemia.

Methodology

Prospective observational study conducted in a neonatal intensive care unit of a tertiary care teaching hospital enrolling 21 neonates with polycythemia who underwent PET. Hemodynamic and echocardiographic parameters were obtained prior to PET and 6 h after procedure.

Results

The mean gestational age of neonates with polycythemia was 35.08 ± 2.35 weeks with a mean birth weight of 1,929 ± 819.2 g. There was a significant improvement noted in heart rate and oxygen saturation post PET procedure (p < 0.05). Right ventricular systolic function parameters showed significant improvement (Tricuspid annular plane systolic excursion, fractional area change, right ventricular output) (p < 0.05). Left ventricular function parameters showed significant improvement (Fractional shortening, left ventricular output, E:A ratio) (p < 0.05). Resolution of symptoms was noted after PET procedure with no adverse events associated with PET.

Conclusion

PET maybe effective in improving heart rate and oxygen saturation levels in polycythemic neonates. It has good short-term hemodynamic stability with improvement in right ventricular systolic, as well as left ventricular systolic and diastolic function. It is a safe and effective procedure with minimal adverse effects. Further studies with larger sample size and a control group would be required to corroborate our findings.

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.

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.

Hemodynamic parameters after Delayed Cord Clamping (DCC) in term neonates: a prospective observational study

Background

Delayed cord clamping (DCC) is practiced worldwide, as standard care in both term and preterm babies. Our aim was to determine the hemodynamic effects of DCC on transitional circulation.

Material and methods

This prospective observational study was carried out in a tertiary care hospital, at Pune, India, from May 2018 to October 2019.Term neonates born during the study period were included. The primary outcome variables of the study were right ventricular output (RVO), left ventricular output (LVO), superior vena cava (SVC) flow (ml/kg/min) and heart rate(HR) at 12 ± 6 and 48 ± 6 h of life measured by point of care functional echocardiography. Inter-observer and intra-observer variability was calculated for these parameters.

Results

Out of a total of 2744 deliveries during the study period, 620 babies were included. Mean gestational age of the enrolled babies was 38.96 ± 1.08 weeks and mean birth weight was 2.9 ± 0.39 kg. Mean heart rate of babies recorded at 12 ± 6 h of life was 127 beats per minute (bpm) whereas it was 128 bpm at 48 ± 6 h of life. RVO {mean (SD)} was 209.55(44.89) and 205.85(46.35) ml/kg/min, LVO {mean (SD)} was 133.68(31.15) and 134.78(29.84) ml/kg/min whereas SVC flow {mean (SD)} was 106.85(26.21) and 109.29(25.11) ml/kg/min at 12 ± 6 and 48 ± 6 h of life respectively. There was good intra-observer agreement in all the variables.

SGA babies had a significantly higher heart rate at 12 ± 6 h of life as compared to AGA babies, although this difference in heart rate could not be appreciated at 48 ± 6 h of life. However SGA babies had a higher LVO, RVO and SVC flow than AGA babies at both the time points of observation.

Conclusion

After DCC there is less fluctuation in the hemodynamic parameters (heart rate, cardiac output) at the two time points of observation.. As compared to AGA babies, SGA babies had a significantly higher baseline heart rate, LVO, RVO and SVC flow. LVO of SGA babies after delayed cord clamping is found to be significantly lower than LVO seen in other studies, favoring the cardio-stabilizing effect of DCC.

Brief rationale

This is the first study with a large sample size evaluating the hemodynamic effects of DCC in term neonates by functional echocardiography. The normative data of heart rate and cardiac output of term, stable babies with small for gestational age(SGA) as a special subgroup undergoing DCC requires further evaluation.

Effects of delayed cord clamping in intrauterine growth-restricted neonates: a randomized controlled trial

The time of cord clamping in intrauterine growth-restricted (IUGR) neonates remains an area of uncertainty. This assessor-blinded randomized controlled trial compared the effects of delayed cord clamping (DCC) with early cord clamping (ECC) on the systemic blood flow (SBF) and cerebral hemodynamics in IUGR neonates of gestational age ≥28 weeks, not requiring resuscitation. Eligible newborns were randomized to DCC (cord clamping after 60 s; n=55) or ECC (cord clamping within 30 s; n=55) group immediately after delivery. The primary outcome variable was superior vena cava (SVC) blood flow at 24±2 h. The secondary outcome variables were right ventricular output (RVO), anterior cerebral artery (ACA) blood flow velocity (BFV), superior mesenteric artery (SMA)-BFV and venous hematocrit at 24±2 h, peak total serum bilirubin (TSB), incidences of polycythemia, intraventricular hemorrhage, respiratory distress, feeding intolerance, and necrotizing enterocolitis, outcome, duration of hospital stay, screening audiometry, and serum ferritin levels at the postnatal age of 3 months. Compared to ECC, DCC was associated with significantly higher SVC flow (101.22±21.02 and 81.27±19.12 mL/kg/min, in DCC and ECC groups, respectively; p<0.0001), and significantly increased RVO, SMA-BFV, venous hematocrit, and serum ferritin levels. Though peak TSB was significantly higher with DCC, duration of phototherapy was comparable. ACA-BFV, incidence of polycythemia, and other outcomes were comparable between the groups.Conclusions: DCC was a safe and beneficial intervention in IUGR infants with an improved SBF and SMA-BFV and an increased hematocrit and serum ferritin levels without higher incidences of polycythemia and requirement of phototherapy for significant hyperbilirubinemia.Trial registration: Clinical Trials Registry of India (CTRI/2019/05/018904) What is Known: • Delayed cord clamping (DCC) increases superior vena cava (SVC) blood flow in preterm neonates. • DCC increases hematocrit and serum ferritin in intrauterine growth-restricted (IUGR) neonates, but there may be an associated risk of polycythemia and neonatal hyperbilirubinemia. What is New: • DCC increases SVC blood flow, right ventricular output, superior mesenteric artery blood flow velocity, venous hematocrit, and serum ferritin in IUGR neonates. • Incidences of polycythemia and duration of phototherapy for significant neonatal hyperbilirubinemia do not increase with DCC.

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.

Bioreactance-derived haemodynamic parameters in the transitional phase in preterm neonates: a longitudinal study

Bioreactance (BR) is a novel, non-invasive technology that is able to provide minute-to-minute monitoring of cardiac output and additional haemodynamic variables. This study aimed to determine the values for BR-derived haemodynamic variables in stable preterm neonates during the transitional period. A prospective observational study was performed in a group of stable preterm (< 37 weeks) infants in the neonatal service of Tygerberg Children's Hospital, Cape Town, South Africa. All infants underwent continuous bioreactance (BR) monitoring until 72 h of life. Sixty three preterm infants with a mean gestational age of 31 weeks and mean birth weight of 1563 g were enrolled. Summary data and time series graphs were drawn for BR-derived heart rate, non-invasive blood pressure, stroke volume, cardiac output and total peripheral resistance index. All haemodynamic parameters were significantly associated with postnatal age, after correction for clinical variables (gestational age, birth weight, respiratory support mode). To our knowledge, this is the first paper to present longitudinal BR-derived haemodynamic variable data in a cohort of stable preterm infants, not requiring invasive ventilation or inotropic support, during the first 72 h of life. Bioreactance-derived haemodynamic monitoring is non-invasive and offers the ability to simultaneously monitor numerous haemodynamic parameters of global systemic blood flow. Moreover, it may provide insight into transitional physiology and its pathophysiology.

Chronological echocardiographic evaluation of left ventricular systolic and diastolic function in term and premature neonatal calves

Echocardiographic studies in human neonatology has demonstrated that prematurity can lead to cardiovascular dysfunction and especially compromises the left ventricular (LV) systolic and diastolic functions. As echocardiographic studies have not been performed on cardiovascular dysfunction in premature calves, we echocardiographically evaluated and compared the LV systolic and diastolic function in full-term and premature calves. We followed the hemodynamical changes of LV during first 3 days of life. Twenty premature calves and 10 healthy term calves were enrolled in the study. 2D, M-mode and Doppler echocardiographic examinations were performed at days 1, 2 and 3 after birth to evaluate LV systolic and diastolic functions. Our findings demonstrated that not only was there LV diastolic dysfunction (55% premature calves, 10% term calf at day 1; 65% premature calves, 10% term calf at day 2 and, 75% premature calves, 20% term calf at day 3), but also LV systolic dysfunction (55% premature calves, 60% term calf at day 1; 55% premature calves, 50% term calf at day 2, and 45% premature calves, 40% term calf at day 3) deteriorated in both term and premature calves. In conclusion, the present study, which was the first comparative echocardiographic assessment of LV systolic and diastolic functions in term and premature newborn calves, showed that both systolic and diastolic dysfunctions might occur in term and premature calves.

Superior vena cava flow: Role, assessment and controversies in the management of perinatal perfusion

The superior vena cava (SVC) is a large vein responsible for the venous return of blood from structures located superior to the diaphragm. The flow in the SVC can be assessed with Doppler ultrasound and can be used as a proxy for cerebral perfusion. Early clinical research studies showed that low SVC flow, particularly if for a prolonged period, was associated with short term morbidity such as intraventricular hemorrhage, mortality, and poorer neurodevelopmental outcomes. However, these findings have not been consistently reported in more recent studies, and the role of SVC flow in early management and as a predictor of poor long-term neurodevelopment has been questioned. This paper provides an overview of SVC assessment, the expected range of findings, and reviews the role of SVC flow as a diagnostic and monitoring tool for the assessment of perinatal perfusion.