Further insights into diastolic dysfunction in first-trimester trisomy-21 fetuses

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

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

The diagnostic performance of the ductus venosus for the detection of cardiac defects in the first trimester: a systematic review and diagnostic test accuracy meta-analysis

PURPOSE

Abnormal flow in the ductus venosus (DV) has been reported to be associated with adverse perinatal outcome, chromosomal abnormalities, and congenital heart defects (CHD). Aneuploid fetuses have increased risk of CHD, but there are discrepancies on the performance of this markers in euploid fetuses. The aim of this meta-analysis was to establish the predictive accuracy of DV for CHD.

METHODS

MEDLINE, EMBASE, and CINAHL were searched from inception to February 2022. No language or geographical restrictions were applied. Inclusion criteria regarded observational and randomized studies concerning first-trimester DV flow as CHD marker. Random effect meta-analyses to calculate risk ratio (RR) with 95% confidence interval (CI), hierarchical summary receiver-operating characteristics (HSROC), and bivariate models to evaluate diagnostic accuracy were used. Primary outcome was the diagnostic performance of DV in detecting prenatal CHD by means of area under the curve (AUROC). Subgroup analysis for euploid, high-risk, and normal NT fetuses was performed. Quality assessment of included papers was performed using QUADAS-2.

RESULTS

Twenty two studies, with a total of 204.829 fetuses undergoing first trimester scan with DV Doppler evaluation, fulfilled the inclusion criteria for this systematic review. Overall, abnormal DV flow at the time of first trimester screening was associated to an increased risk of CHD (RR 6.9, 95% CI 3.7-12.6; I2 = 95.2%) as well in unselected (RR: 6.4, 95% CI 2.5-16.4; I2 = 93.3%) and in euploid (RR: 6.45, 95% CI 3.3-12.6; I2 = 95.8%) fetuses. The overall diagnostic accuracy of abnormal DV in detecting CHD was good in euploid fetuses with an AUROC of 0.81 (95% CI 0.78-0.84), but it was poor in the high-risk group with an AUROC of 0.66 (95% CI 0.62-0.70) and in the unselected population with an AUROC of 0.44 (95% CI 0.40-0.49).

CONCLUSIONS

Abnormal DV in the first trimester increases the risk of CHD with a moderate sensitivity for euploid fetuses. In combination with other markers (NT, TV regurgitation) could be helpful to identify fetuses otherwise considered to be at low risk for CHD. In addition to the improvement of the fetal heart examination in the first trimester, this strategy can increase the detection of major CHD at earlier stage of pregnancy.

Fetal left ventricular myocardial performance index measured at 11-14 weeks of gestation in fetuses with an increased nuchal translucency

OBJECTIVE

This study aimed to evaluate the effect of an increase in nuchal translucency (NT) thickness on the myocardial performance index (MPI) in fetuses without cardiac anomaly in the first trimester and to determine whether a difference in MPI between those with and without trisomy 21 in these fetuses could be determined.

METHODS

The study group consisted of 53 pregnancies complicated with increased NT thickness without any associated structural anomalies. Forty-six gestational age-matched pregnant women whose fetuses had normal NT thickness were enrolled as the control group.

RESULTS

In the increased NT thickness group, the mean isovolumetric relaxation time (IRT) value (0.050 ± 0.011 s) was significantly higher and the mean ejection time (ET) value (0.149 ± 0.010 s) was significantly lower than those values in the normal NT thickness group (0.045 ± 0.005 and 0.155 ± 0.009 s, p = 0.023 and p = 0.009, respectively). We found a significantly higher mean left MPI value in the increased NT thickness group (0.574 ± 0.153) versus the normal NT thickness group (0.487 ± 0.107, p < 0.001). Within the increased NT thickness group, the mean left MPI value was similar in the fetuses with normal karyotype and those with trisomy 21 (p = 0.419).

CONCLUSION

We demonstrated a significantly greater mean MPI value in the increased NT thickness group than in the normal NT thickness group. Within the increased NT thickness group, no differences in the left MPI value in the fetuses with normal karyotype and the fetuses with trisomy 21 were found.

First Trimester Tricuspid Regurgitation: Clinical Significance

Tricuspid regurgitation is a cardiac valvular anomaly that consists of the return of blood to the right atrium during systole due to incomplete valve closure. This structure can be visualized on ultrasound between 11 and 14 weeks of gestation in most cases. Despite being a common finding, even in healthy fetuses, the presence of tricuspid regurgitation may be associated with chromosomal and structural abnormalities. The evaluation of tricuspid flow and the presence of regurgitation on first-trimester ultrasound has shown promising results regarding its role in the early detection of aneuploidies, congenital heart defects, and other adverse perinatal outcomes. This review article aims to demonstrate the importance of tricuspid regurgitation as a secondary marker, and consequently, significant benefits of its early detection when added to the combined first-trimester screening. Its value will be discussed, namely its sensitivity and specificity, alone and together with other current markers in the fetal assessment performed in the first-trimester ultrasound.

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.

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.

Cardiac defects, nuchal edema and abnormal lymphatic development are not associated with morphological changes in the ductus venosus

BACKGROUND

In human fetuses with cardiac defects and increased nuchal translucency, abnormal ductus venosus flow velocity waveforms are observed. It is unknown whether abnormal ductus venosus flow velocity waveforms in fetuses with increased nuchal translucency are a reflection of altered cardiac function or are caused by local morphological alterations in the ductus venosus.

AIM

The aim of this study was to investigate if the observed increased nuchal translucency, cardiac defects and abnormal lymphatic development in the examined mouse models are associated with local changes in ductus venosus morphology.

STUDY DESIGN

Mouse embryos with anomalous lymphatic development and nuchal edema (Ccbe1(-/-) embryos), mouse embryos with cardiac defects and nuchal edema (Fkbp12(-/-), Tbx1(-/-), Chd7(fl/fl);Mesp1Cre, Jarid2(-/-NE+) embryos) and mouse embryos with cardiac defects without nuchal edema (Tbx2(-/-), Fgf10(-/-), Jarid2(-/-NE-) embryos) were examined. Embryos were analyzed from embryonic day (E) 11.5 to 15.5 using markers for endothelium, smooth muscle actin, nerve tissue and elastic fibers.

RESULTS

All mutant and wild-type mouse embryos showed similar, positive endothelial and smooth muscle cell expression in the ductus venosus at E11.5-15.5. Nerve marker and elastic fiber expression were not identified in the ductus venosus in all investigated mutant and wild-type embryos. Local morphology and expression of the used markers were similar in the ductus venosus in all examined mutant and wild-type embryos.

CONCLUSIONS

Cardiac defects, nuchal edema and abnormal lymphatic development are not associated with morphological changes in the ductus venosus. Ductus venosus flow velocity waveforms most probably reflect intracardiac pressure.