Myocardial tissue Doppler changes in patients with bronchopulmonary dysplasia

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.

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.

Atrial septal defect closure is associated with improved clinical status in patients ≤ 10 kg with bronchopulmonary dysplasia

Patients with bronchopulmonary dysplasia (BPD) have shown clinical improvement after secundum atrial septal defect (ASD) closure. We sought to determine if this post-ASD closure improvement is secondary to the expected course in BPD patients or related to the closure itself. A novel BPD-ASD score was created to assess patients' clinical status (higher score = worse disease) and applied to 10 BPD-ASD inpatients weighing ≤ 10 kg who underwent ASD closure. The score and its subcomponents were retrospectively calculated serially ranging from 8 weeks pre- to 8 weeks post-intervention, and pre- and post-intervention score slopes were created. These slopes were compared using mixed regression modeling with an interaction term. There was a significant difference in pre- versus post-intervention slope with the most score drop the first week post-intervention (-2.1 + /- 0.8, p = 0.014). The mean score also dropped through weeks 2 (slope -0.8 + /- 0.8, p = 0.013) and 4 (slope -1.0 + /- 0.5, p = 0.001) post-intervention. There was a significant difference in pre- and post-intervention slopes for diuretics (p = 0.018) and the combined score of respiratory support, FiO2 need, and respiratory symptoms (p = 0.018). This study demonstrated significant improvement in BPD-ASD score, diuretic need, and respiratory status after ASD closure in BPD-ASD patients ≤ 10 kg that was outside of the natural course of BPD. Our study was limited by its small, single-center, retrospective nature. Future studies should be performed in a larger multicenter population to both validate the scoring system and compare to non-intervention infants.

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.

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.

Influence of extreme prematurity and bronchopulmonary dysplasia on cardiac function

OBJECTIVE

Prematurity and bronchopulmonary dysplasia (BPD) are associated with poorly understood abnormalities of ventricular function. We therefore comprehensively compared biventricular function in infants with and without BPD.

METHODS

Prospective observational study in extremely preterm infants with (n = 20) and without (n = 38) BPD using conventional and advanced echocardiography at 28 days (T1) and near-term (T2).

RESULTS

Infants with BPD had lower birth gestational age (26.7±1.9 vs 27.4±1.1 weeks, p = 0.047) and weight (884±207 vs 1108±190 g, p = 0.0001). BPD was associated with larger right ventricles (RV) and reduced RV systolic strain rate at T1 and pulmonary hypertensive indicators at T2 (pulmonary artery acceleration time BPD 51±17 vs no BPD 63±12 ms, p = 0.017). At T1/T2, infants with BPD had lower RV tissue Doppler velocities (e', a' and s) and higher E/e' ratios (T1: BPD 10.4±2.4 vs no BPD 6.2±3.1 cm/sec, p = 0.001; T2: BPD 8.0±3.1 vs no BPD 5.6±2.6 cm/sec, p = 0.02), altered LV diastolic function (apical circumferential T1 early diastolic strain rate BPD 2.8±0.8 vs no BPD 3.6±1.0 /sec, p = 0.04; T2 late diastolic strain rate, BPD 2.29 ± 0.99 vs no BPD 1.67±0.84 /sec, p = 0.03) and LV rotational mechanics (T1: twist rate BPD 90±16 vs no BPD 130±48 deg/sec^, p = 0.008; untwist rate (UTR) BPD -69±90 vs no BPD -147±68 deg/sec, p = 0.008; torsion BPD 2.78±0.56 vs no BPD 4.48±1.74 deg/cm, p = 0.009; and T2: UTR BPD -132±69 vs no BPD -179±57 deg/sec, p = 0.013).

CONCLUSION

BPD is associated with altered RV diastolic function that persists near term, with elevated pulmonary vascular resistance, and with persistent alterations in LV apical strain rate and rotational mechanics.

Left Ventricle Phenotyping Utilizing Tissue Doppler Imaging in Premature Infants with Varying Severity of Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD) is characterized by alveolar-capillary simplification and is associated with pulmonary hypertension (PH) in preterm infants. The contribution of left ventricle (LV) disease towards this severe BPD-PH phenotype is not well established. We aimed to describe the longitudinal trajectory of the LV function as measured by tissue Doppler imaging (TDI) and its association with BPD-PH. We retrospectively assessed prospectively acquired clinical and echocardiographic data from 77 preterm infants born between 2011 and 2013. We characterized the LV function by measuring systolic and diastolic myocardial velocities (s’, e’, a’), isovolumetric relaxation time (IVRT), and myocardial performance index with TDI at three time periods from 32 and 36 weeks, postmenstrual age through one year of age. We also measured post systolic motion (PSM), a marker of myocardial dysfunction that results from asynchronous movement of the ventricular walls, and not previously described in preterm infants. Patients were stratified into groups according to BPD severity and the presence of PH and compared over time. Conventional TDI measures of the LV function were similar between groups, but the septal PSM was significantly prolonged over the first year of age in patients with BPD-PH. PSM provides a novel objective way to assess the hemodynamic impact of lung and pulmonary vascular disease severity on LV function in preterm infants with BPD and PH.

Assessing pulmonary circulation in severe bronchopulmonary dysplasia using functional echocardiography

Pulmonary hypertension (PH) is common in infants with severe bronchopulmonary dysplasia (BPD) and increases the risk of death. The objectives of this preliminary study were to compare responses of pulmonary circulation parameters to 100% oxygen (O₂) and inhaled nitric oxide (iNO) in infants with BPD and PH using echocardiography. Responses between fetal growth restriction (FGR) and appropriate for gestational age infants were compared. Ten infants <28 weeks GA at birth were assessed at ≥36 weeks corrected gestation. Baseline echocardiography1 was performed which was repeated (echocardiography2) after 30 minutes of O₂. After a gap of 2–3 hours, iNO was administered for 15 minutes and echocardiography3 was performed, followed by iNO weaning. The gestation and birthweight of the cohort were 25.9 ± 1.6 weeks and 612 ± 175 g. Assessments were performed at 38.7 ± 1.4 weeks corrected gestational age. Baseline time to peak velocity: right ventricular ejection time (TPV/RVETc) increased from 0.24 ± 0.02 to 0.27 ± 0.02 (O₂, p = .01) and 0.31 ± 0.03 (iNO, p < .001), indicating a decrease in pulmonary vascular resistance [PVR]. Baseline tricuspid annular plane systolic excursion (TAPSE) increased from 8.1 ± 0.6 mm to 9.3 ± 0.7 mm (O₂, p = .01) and 10.5 ± 1.1 mm (iNO, p = .0004), indicating improved ventricular systolic performance. Percentage change for all parameters was greater with iNO. Significant correlations between cardiac performance and PVR were noted. FGR infants noted higher baseline PVR (TPV/RVETc, 0.21 ± 0.02 vs. 0.25 ± 0.01, p = .002), lower ventricular performance (TAPSE, 7 ± 1.2 mm vs. 8.6 ± 6 mm, p = .003), and lower percentage change with O₂ and iNO. A reactive component of pulmonary circulation provides real‐time physiological information, which could rationalize treatment decisions.

Soluble Klotho, a biomarker and therapeutic strategy to reduce bronchopulmonary dysplasia and pulmonary hypertension in preterm infants

Preterm infants with bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH) have accelerated lung aging and poor long-term outcomes. Klotho is an antiaging protein that modulates oxidative stress, angiogenesis and fibrosis. Here we test the hypothesis that decreased cord Klotho levels in preterm infants predict increased BPD-PH risk and early Klotho supplementation prevents BPD-like phenotype and PH in rodents exposed to neonatal hyperoxia. In experiment 1, Klotho levels were measured in cord blood of preterm infants who were enrolled in a longitudinal cohort study. In experiment 2, using an experimental BPD-PH model, rat pups exposed to room air or hyperoxia (85% O₂) were randomly assigned to receive every other day injections of recombinant Klotho or placebo. The effect of Klotho on lung structure, PH and cardiac function was assessed. As compared to controls, preterm infants with BPD or BPD-PH had decreased cord Klotho levels. Early Klotho supplementation in neonatal hyperoxia-exposed rodents preserved lung alveolar and vascular structure, attenuated PH, reduced pulmonary vascular remodeling and improved cardiac function. Together, these findings have important implications as they suggest that perinatal Klotho deficiency contributes to BPD-PH risk and strategies that preserve Klotho levels, may improve long-term cardiopulmonary outcomes in preterm infants.

Serum and Urinary N-Terminal Pro-brain Natriuretic Peptides as Biomarkers for Bronchopulmonary Dysplasia of Preterm Neonates

Bronchopulmonary dysplasia (BPD) is a common cause of respiratory illness in preterm newborns with high morbidity and mortality rates. At present, there are no early prognostic biomarkers that can be used in clinical practice to predict the development of BPD. In this review, we critically appraise evidence regarding the use of serum N-terminal pro-brain natriuretic peptide (NTproBNP) levels as a biomarker for BPD in neonates. Furthermore, we summarize studies assessing the feasibility of urinary NTproBNP levels as a non-invasive method to predict BPD in preterm infants. Multiple studies reported a strong association between NTproBNP serum levels and the onset of BPD. For urinary NTproBNP there is scarce evidence showing an association with BPD. Given the promising data obtained by preliminary studies, further assessment of this biomarker in both serum and urine is needed. Standardized reference values should be defined before conducting any further clinical studies.

Right ventricular myocardial performance index in pediatric patients with bronchopulmonary dysplasia-related pulmonary hypertension

INTRODUCTION

This study aims to assess the utility of right ventricular myocardial performance index (RVMPI) as a potential echocardiographic tool to evaluate and serially follow patients with bronchopulmonary dysplasia (BPD) and pulmonary hypertension (PH).

METHODS

We performed a retrospective chart review of all hemodynamic cardiac catheterizations performed January 2011 to December 2016 in patients born premature and with diagnosed BPD up to 4 years of age-excluding patients with significant congenital heart defects. Echocardiograms performed within 24 hours of the cardiac catheterization were reviewed, and a blinded RVMPI was calculated. The primary endpoint was correlation of invasive catheterization hemodynamics to noninvasive echocardiographic RVMPI measurement.

RESULTS

A total of 49 individual patients met complete study criteria, and 10 of those patients underwent repeat cardiac catheterization. Median age at the time of assessment was 8 months (25%-75%, 4-18 months), and the cohort had a calculated RVMPI mean of 0.39 (±0.19), with 73% (43/59) having a RVMPI >0.28. A statistically significant correlation was found between the RVMPI and the baseline hemodynamics during catheterization with regard to the initial mean pulmonary arterial pressure (r = 0.58; P < 0.01) as well as the calculated pulmonary vascular resistance (r = 0.34; P = 0.01).

CONCLUSIONS

This study demonstrates the utility of RVMPI for evaluation of PH in patients with prematurity and BPD. An increased RVMPI by noninvasive echocardiography was found to correlate with increased mean pulmonary arterial pressure and pulmonary vascular resistance measured during invasive cardiac catheterization. Large-scale validation of this study is being planned.

Echocardiographic Measurements of Right Ventricular Mechanics in Infants with Bronchopulmonary Dysplasia at 36 Weeks Postmenstrual Age

OBJECTIVE

To test the hypothesis that specific echocardiographic measurements of right ventricular (RV) mechanics at 36 weeks postmenstrual age (PMA) are associated with the severity of bronchopulmonary dysplasia (BPD).

STUDY DESIGN

A subset of 93 preterm infants (born between 27 and 29 weeks of gestation) was selected retrospectively from a prospectively enrolled cohort. BPD was defined using the National Institutes of Health workshop definition, with modifications for oxygen reduction testing and altitude. The cohort was divided into no-BPD and BPD groups using previously published methodology for analyses. Echocardiographic measurements of RV function (ie, tricuspid annular plane systolic excursion, fractional area of change, systolic-to-diastolic ratio, tissue Doppler myocardial performance index, and RV strain), RV remodeling/morphology (end-systolic left ventricular eccentricity index), and RV afterload (pulmonary artery acceleration time measure) were evaluated at 36 weeks PMA. Multivariable logistic regression determined associations between RV measurements and BPD severity.

RESULTS

Compared with the no-BPD cohort, the BPD group had lower birth weight z-scores (P = .04) and trended toward a male predominance (P = .08). After adjusting for birth weight z-score, gestational age, and sex, there were no between-group differences in echocardiographic measurements except for the eccentricity index (scaled OR [0.1-unit increase], 1.49; 95% CI, 1.13-2.12; P = .01).

CONCLUSIONS

Among conventional and emerging echocardiographic measurements of RV mechanics, eccentricity index was the sole variable independently associated with BPD severity in this study. The eccentricity index may be a useful echocardiographic measurement for characterizing RV mechanics in patients with BPD at 36 weeks PMA.

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

Neonatologists can use echocardiography for real-time assessment of the hemodynamic state of neonates to support clinical decision-making. There is a large body of evidence showing the shortcomings of conventional echocardiographic indices in neonates. Newer imaging modalities have evolved. Tissue Doppler imaging is a new technique that can provide measurements of myocardial movement and timing of myocardial events and may overcome some of the shortcomings of conventional techniques. The high time resolution and its ability to assess left and right cardiac function make tissue Doppler a favorable technique for assessing heart function in neonates. The aim of this review is to provide an up-to-date overview of tissue Doppler techniques for the assessment of cardiac function in the neonatal context, with focus on measurements from the atrioventricular (AV) plane. We discuss basic concepts, protocol for assessment, feasibility, and limitations, and we report reference values and give examples of its use in neonates.

Clinical Utility of Echocardiography for Early and Late Pulmonary Hypertension in Preterm Infants: Relation with Bronchopulmonary Dysplasia

Background

We evaluated early and late pulmonary hypertension (PH) in preterm infants and its relation with bronchopulmonary dysplasia (BPD).

Methods

Sixty-seven preterm infants < 30 weeks' gestation underwent echocardiography within 14 days after birth for early PH and over 28 days after birth for late PH. We measured tricuspid regurgitation (TR) peak velocity, pulse Doppler-derived myocardial performance index (MPI) of right ventricle (RV) (RV MPI), eccentricity index (EI), and tricuspid annular plane systolic excursion (TAPSE).

Results

The median gestation age of patients was 27 weeks (range, 23–30 weeks) and median birth weight was 1030 g (range, 450–1780 g). TR peak velocity was measured only in 19 patients (28.4%). Patients with symptomatic early PH (n = 11) showed a significantly lower systolic EI and a significantly higher incidence of RV MPI > 0.38 and TAPSE < 0.5 cm than patients without PH. The incidence of symptomatic early PH was highest in severe BPD, although this was not statistically significant. Early echocardiographic parameters are not associated with BPD development. Patients with severe BPD showed a significantly higher RV MPI and a significantly higher incidence of RV MPI > 0.38 than patients with mild BPD, and a significantly lower systolic EI and a significantly higher incidence of systolic EI < 0.81 than patients without BPD.

Conclusion

Systolic EI, RV MPI, and TAPSE were well represented symptomatic early PH, while systolic EI and RV MPI could be useful parameters for identifying late PH in preterm infants with BPD, even if they did not present PH symptoms.

Echocardiographic right ventricular function correlations with cardiac catheterisation data in biventricular congenital heart patients

BACKGROUND

Newer echocardiographic techniques may allow for more accurate assessment of right ventricular function. Adult studies have correlated these echocardiographic measurements with invasive data, but minimal data exist in the paediatric congenital heart population. The purpose of this study was to evaluate echocardiographic measurements that correlate best with right ventricular systolic and diastolic catheterisation parameters.

METHODS

Patients with two-ventricle physiology who underwent simultaneous echocardiogram and cardiac catheterisation were included in this study. Right ventricular systolic echocardiographic data included fractional area change, displacement, tissue Doppler imaging s' wave, global longitudinal strain, and strain rate s' wave. Diastolic echocardiographic data included tricuspid E and A waves, tissue Doppler imaging e' and a' waves, and strain rate e' and a' waves. E/tissue Doppler imaging e', tissue Doppler imaging e'/tissue Doppler imaging a', E/strain rate e', and strain rate e'/strain rate a' ratios were also calculated. Catheterisation dP/dt was used as a marker for systolic function and right ventricular end-diastolic pressure for diastolic function.

RESULTS

A total of 32 patients were included in this study. The median age at catheterisation was 3.1 years (0.3-17.6 years). The DP/dt was 493±327 mmHg/second, and the right ventricular end-diastolic pressure was 7.7±2.4 mmHg. There were no significant correlations between catheterisation dP/dt and systolic echocardiographic parameters. Right ventricular end-diastolic pressure correlated significantly with strain rate e' (r=-0.4, p=0.02), strain rate a' (r=-0.5, p=0.03), and E/tissue Doppler imaging e' (r=0.4, p=0.04).

CONCLUSION

Catheterisation dP/dt did not correlate with echocardiographic measurements of right ventricular systolic function. Strain rate and tissue Doppler imaging analysis significantly correlated with right ventricular end-diastolic pressure. These values should be further studied to determine whether they may be used as an alternative method to estimate right ventricular end-diastolic pressure in this patient population.

Diagnostics in Children and Adolescents with Suspected or Confirmed Pulmonary Hypertension

We provide a practical approach on the initial assessment and diagnostic work-up of children and adolescents with pulmonary hypertension (PH). Transthoracic echocardiography (TTE) often serves as initial study tool before invasive cardiac catheterization. Misinterpretation of TTE variables may lead to missed or delayed diagnosis with devastating consequences, or unnecessary invasive diagnostics that have inherited risks. In addition to clinical and biochemical markers, serial examination of patients with PH using a standardized TTE approach, determining conventional and novel echocardiographic variables, may allow early diagnosis and treatment in paediatric PH. Cardiac magnetic resonance imaging and computed tomography represent important non-invasive imaging modalities, that together with TTE may enable comprehensive assessment of ventricular function and pulmonary hemodynamics. Invasive assessment of haemodynamics (ventricular, pulmonary) and testing of acute vasoreactivity in the catheterization laboratory is still the gold standard for the diagnosis of PH and pulmonary hypertensive vascular disease (PHVD) in children and for the initiation of specific PH therapy. We suggest the regular assessment of prognostic TTE variables as part of a standardized approach for initial diagnosis of children with PH. Overreliance on any single TTE variable should be avoided as it detracts from the overall diagnostic potential of a standardized TTE examination for PH.

Echocardiographic evaluation of right ventricular function in preterm infants with bronchopulmonary dysplasia

AIM

To evaluate right ventricular function in preterm infants with and without bronchopulmonary dysplasia.

METHODS

Eighty-nine preterm infants (<32 weeks) were divided into three groups: (1) no-bronchopulmonary dysplasia (n=32); (2) mild-bronchopulmonary dysplasia (n=35); (3) severe-bronchopulmonary dysplasia (n=15). Right ventricular echocardiographic parameters included the following: (1) pulsed-wave Doppler through the tricuspid valve (E/A ratio), pulmonary artery acceleration time, right ventricular ejection time, right ventricular velocity-time integral; (2) tissue Doppler measurements of myocardial velocities and atrioventricular conduction times; (3) pulsed-wave Doppler and tissue Doppler evaluation of myocardial performance index and E/E' ratio; and (4) M-mode detection of right ventricular end-diastolic wall diameter.

RESULTS

The severe-bronchopulmonary dysplasia group had higher mean right ventricular myocardial performance index (on the 28th day of life by pulsed-wave Doppler) than the no-bronchopulmonary dysplasia (P=.014) or mild-bronchopulmonary dysplasia (P=.031) groups; no differences were found between no-bronchopulmonary dysplasia and mild-bronchopulmonary dysplasia groups (P=.919). A reduction in right ventricular myocardial performance index at later time points was observed in all three groups (P<.05). We found no differences between preterm infants with differing bronchopulmonary dysplasia severity in other right ventricular echocardiographic parameters.

CONCLUSION

Right ventricular myocardial performance index measured by pulsed-wave Doppler indicates impaired right ventricular function in preterm infants with severe bronchopulmonary dysplasia.

A new look at bronchopulmonary dysplasia: postcapillary pathophysiology and cardiac dysfunction

Pulmonary hypertension (PH) and right ventricular function are the focus of cardiovascular effects of bronchopulmonary dysplasia (BPD). We assessed cardiac indexes reflecting systemic afterload and pulmonary venous back pressure as pathophysiologic factors. Cardiac parameters were measured by conventional echocardiography in 20 preterm infants with severe BPD and compared with those of 10 preterm infants with no BPD and 20 healthy term infants. In infants with severe BPD, PH was noted in 5 (25%) by tricuspid regurgitation Doppler jet ≥2.8 m/s and in 15 (75%) by time to peak velocity/right ventricular ejection time <0.34. Among systemic cardiac indexes, significant impairment of diastolic measures was noted in the BPD group compared with infants with no BPD and term infants. The significance persisted after adjusting for gestational age and birth weight. These included transmitral E/A ratio (1.07 ± 0.07 vs. 0.91 ± 0.04 vs. 0.89 ± 0.09; P < 0.0001), isovolumic relaxation time (68.8 ± 3.9 vs. 58.5 ± 7.8 vs. 54.2 ± 5.7 ms ; P < 0.0001), mitral valve stroke volume (4.7 ± 0.7 vs. 5.6 ± 0.6 vs. 5.9 ± 0.1; P = 0.002), and myocardial performance index (0.33 ± 0.05 vs. 0.28 ± 0.01 vs. 0.27 ± 0.05; P = 0.03). Left ventricular output was significantly lower in the BPD cohort (183 ± 45 vs. 189 ± 9 vs. 191 ± 32 mL/kg/min; P = 0.03). Altered systemic (left-sided) cardiac function was noted in infants with BPD, which may lead to pulmonary venous congestion contributing to a continued need for respiratory support.

Right ventricular performance using myocardial deformation imaging in infants with bronchopulmonary dysplasia

OBJECTIVE

Right ventricular (RV) performance among infants with bronchopulmonary dysplasia (BPD) remains poorly understood. We tested the hypothesis that myocardial deformation imaging (MDI) strain and strain rate would allow for differentiation between infants with severe and milder forms of BPD, independent of tissue Doppler imaging (TDI) and superior to conventional echocardiographic measurements.

STUDY DESIGN

Infants with various severities of BPD (11 with none or mild, 13 with moderate and 10 with severe) underwent conventional echocardiography, TDI and MDI assessments at >36 weeks of corrected gestational age. BPD severity grading was determined according to the National Institutes of Child Health and Disease workshop rating scale by physicians blinded to the echocardiogram results. Group data were compared with one-way analysis of variance or Kruskal-Wallis tests, with post hoc multiple comparisons.

RESULTS

No differences in traditional echocardiographic parameters or TDI among the three BPD severity groups were observed; none of the infants had evidence of pulmonary hypertension. Using MDI, infants with severe BPD had lower peak global systolic strain than did infants with moderate BPD (P<0.01) or mild/none BPD (P<0.01). Early and late diastolic strain rate measurements were similar across the three groups.

CONCLUSIONS

Among infants with severe forms of BPD, evidence of abnormal RV systolic function was detected with MDI, but not traditional echocardiographic or TDI measurements. Infants with severe forms of BPD may represent a particularly high-risk subgroup for decreased RV performance warranting cardiac surveillance. MDI should be considered as a method to quantitate RV function in this population.

Clinical Utility of Echocardiography for the Diagnosis and Prognosis in Children with Bronchopulmonary Dsyplasia

Background

Bronchopulmonary dysplasia (BPD) may result in chronic pulmonary artery hypertension and right ventricular (RV) dysfunction. Various echocardiographic assessments of RV dysfunction have been used to determine whether echocardiographic measurements of premature infants with BPD could provide sensitive measures of RV function that correlates with BPD severity.

Methods

Twenty-eight control subjects without BPD (non BPD group), 28 patients with mild BPD, 11 patients with moderate BPD, and six patients with severe BPD underwent echocardiograms with standard measurement such as ejection fraction by M-mode, tricuspid regurgitation pressure gradient, myocardial performance index (MPI) derived from pulse Doppler, and tissue Doppler imaging (TDI) measurements. BPD severity was classified by the NICHD/NHLBI/ORD workshop rating scale. Twenty-eight control subjects without BPD (non BPD group), 28 patients with mild BPD, 11 patients with moderate BPD, and six patients with severe BPD underwent echocardiograms with standard measurement such as ejection fraction by M-mode, tricuspid regurgitation pressure gradient, myocardial performance index (MPI) derived from pulse Doppler, and TDI measurements. BPD severity was classified by the NICHD/NHLBI/ORD workshop rating scale.

Results

None of the standard echocardiographic findings was significantly different between the control group and BPD groups. However, mean septal TDI-MPI of the severe BPD group (0.68 ± 0.06) was significantly (p < 0.01) higher than that of the non-BPD (0.58 ± 0.10) or the mild BPD group (0.59 ± 0.12). In addition, mean RV TDI-MPI of the severe BPD group (0.71 ± 0.13) was significantly (p < 0.05) higher than that of the non-BPD group (0.56 ± 0.08) or the mild BPD group (0.60 ± 0.125). Linear regression showed a good correlation between the severity of BPD and RV TDI-MPI (p = 0.01, R = 0.30) or septal TDI-MPI (p = 0.04, R = 0.24).

Conclusion

Echocardiographic evaluation of RV function based on an assessment of RV TDI-MPI can provide RV dysfunction parameter in premature infants with BPD.

Assessment of myocardial function in preterm infants with chronic lung disease using tissue Doppler imaging

OBJECTIVES

To assess myocardial function and presence of pulmonary hypertension (PH) using both tissue Doppler imaging (TDI) and conventional echocardiography in preterm infants of <32 weeks gestation with chronic lung disease (CLD).

DESIGN

Prospective observational study.

SETTING

Tertiary neonatal intensive care unit.

PATIENTS

Three groups of preterm infants were recruited. Group 1-CLD receiving positive pressure airway support including high-flow humidified nasal cannula oxygen (n=25), group 2-CLD receiving low-flow nasal oxygen (n=25) and group 3-no CLD (n=22).

METHODS

Echocardiography was performed around 36 weeks corrected gestational age. Myocardial function and PH were assessed using both conventional (left ventricular fractional shortening (LVFS) and left ventricular output (LVO), tricuspid regurgitation and ventricular septal flattening) and TDI techniques (myocardial velocities, myocardial performance index (MPI) and right ventricular isovolumetric relaxation time (RV-IVRT)).

RESULTS

The MPI of right ventricle (RV) and left ventricle (LV) was significantly higher in CLD infants: mean RV MPI group 1-0.79, group 2-0.65 and group3-0.52. LV MPI: group 1-0.77, group 2-0.70 and group 3-0.45. There was a trend towards higher MPIs in group 1 compared with group 2. LVFS and LVO were similar across all three groups. RV-IVRT was also significantly higher in infants with CLD infants (group 1-64 milliseconds, group 2-62 milliseconds and group 3-52 milliseconds). PH was not detected by conventional echocardiography.

CONCLUSIONS

Infants with CLD have evidence of relative biventricular dysfunction and higher pulmonary arterial blood pressure as demonstrated by TDI, which were not detected by conventional echocardiography.

Transthoracic echocardiography in the evaluation of pediatric pulmonary hypertension and ventricular dysfunction

Transthoracic echocardiography (TTE) is the most accessible noninvasive diagnostic procedure for the initial assessment of pediatric pulmonary hypertension (PH). This review focuses on principles and use of TTE to determine morphologic and functional parameters that are also useful for follow-up investigations in pediatric PH patients. A basic echocardiographic study of a patient with PH commonly includes the hemodynamic calculation of the systolic pulmonary artery pressure (PAP), the mean and diastolic PAP, the pulmonary artery acceleration time, and the presence of a pericardial effusion. A more detailed TTE investigation of the right ventricle (RV) includes assessment of its size and function. RV function can be evaluated by RV longitudinal systolic performance (e.g., tricuspid annular plane systolic excursion), the tricuspid regurgitation velocity/right ventricular outflow tract velocity time integral ratio, the fractional area change, tissue Doppler imaging-derived parameters, strain measurements, the systolic-to-diastolic duration ratio, the myocardial performance (Tei) index, the RV/left ventricle (LV) diameter ratio, the LV eccentricity index, determination of an enlarged right atrium and RV size, and RV volume determination by 3-dimensional echocardiography. Here, we discuss the potential use and limitations of TTE techniques in children with PH and/or ventricular dysfunction. We suggest a protocol for TTE assessment of PH and myocardial function that helps to identify PH patients and their response to pharmacotherapy. The outlined protocol focuses on the detailed assessment of the hypertensive RV; RV-LV crosstalk must be analyzed separately in the evaluation of different pathologies that account for pediatric PH.

Biomarkers for Bronchopulmonary Dysplasia in the Preterm Infant

Bronchopulmonary dysplasia (BPD) is a chronic inflammatory lung disease of very-low-birth-weight (VLBW) preterm infants, associated with arrested lung development and a need for supplemental oxygen. Over the past few decades, the incidence of BPD has significantly raised as a result of improved survival of VLBW infants requiring mechanical ventilation. While early disease detection is critical to prevent chronic lung remodeling and complications later in life, BPD is often difficult to diagnose and prevent due to the lack of good biomarkers for identification of infants at risk, and overlapping symptoms with other diseases, such as pulmonary hypertension (PH). Due to the current lack of effective treatment available for BPD and PH, research is currently focused on primary prevention strategies, and identification of biomarkers for early diagnosis, that could also represent potential therapeutic targets. In addition, novel histopathological, biochemical, and molecular factors have been identified in the lung tissue and in biological fluids of BPD and PH patients that could associate with the disease phenotype. In this review, we provide an overview of biomarkers for pediatric BPD and PH that have been identified in clinical studies using various biological fluids. We also present a brief summary of the information available on current strategies and guidelines to prevent and diagnose BPD and PH, as well as their pathophysiology, risk factors, and experimental therapies currently available.

Right Ventricular Function in Infants with Bronchopulmonary Dysplasia: Association with Respiratory Sequelae

BACKGROUND

While cor pulmonale has been noted in infants with bronchopulmonary dysplasia (BPD), information on right ventricular (RV) function is limited.

OBJECTIVE

To assess RV function in infants with severe BPD and ascertain correlation with respiratory outcomes.

METHODS

We prospectively assessed RV function using tissue Doppler imaging (TDI), 2D fractional area change (FAC), M-mode tricuspid annular plane systolic excursion (TAPSE) and myocardial performance index (MPI) using echocardiography. Additionally, we compared RV function with preterm infants with no BPD.

RESULTS

Eighteen preterm infants with severe BPD were enrolled at 36 weeks' gestation. Higher E/E' (r = 0.78, p < 0.0001) and lower FAC (r = 0.8, p < 0.0001) showed strong correlations with the subsequent duration of respiratory support. Correlations with TDI isovolumic velocity and Tei index were significant (-0.69, p = 0.002 and 0.58, p = 0.011, respectively). On comparison with infants with no BPD, TDI peak systolic velocities (0.06 ± 0.01 vs. 0.09 ± 0.01 m/s, p < 0.0001), peak isovolumic systolic velocities (0.05 ± 0.009 vs. 0.07 ± 0.008 m/s, p < 0.0001) and RV FAC (31 ± 4.7 vs. 36 ± 3.6%, p = 0.019) were significantly lower. Cardiac relaxation was impaired [higher TDI E/E' ratio (9.6 ± 1.8 vs. 5.2 ± 0.5, p < 0.0001) and higher RV MPI (0.33 ± 0.03 vs. 0.25 ± 0.03, p < 0.0001)].

CONCLUSIONS

Impaired RV performance in the infants with severe BPD at 36 weeks' corrected gestation correlated with a longer duration of subsequent respiratory support.

Cardiac Mechanics in Children with Bronchopulmonary Dysplasia

BACKGROUND

Disruption of pulmonary vasculogenesis occurs in bronchopulmonary dysplasia (BPD). Increased impedance to pulmonary flow secondary to abnormal vascular development may affect ventricular mechanics.

OBJECTIVES

We aimed to test the hypothesis that cardiac mechanics are altered in prematurely born children with BPD.

METHODS

A cohort of 47 children was studied: 22 aged 48.9 ± 6.4 months born preterm with BPD (group I), 13 aged 46.3 ± 8.1 months born preterm without BPD (group II), and 12 healthy children aged 53.4 ± 12.2 months born at term (group III). Left (LV) and right ventricular (RV) strain and strain rate were assessed by speckle-tracking echocardiography.

RESULTS

The global RV systolic strain rate (p = 0.022) was significantly lower, while RV systolic strain (p = 0.05) and early diastolic strain rate (p = 0.05) and LV longitudinal systolic strain rate (p = 0.06) also tended to be lower in group I than group III. Group I also tended to have lower RV systolic strain (p = 0.09) and early diastolic strain rate (p = 0.049) and LV longitudinal systolic strain rate (p = 0.08) than group II. An increasing trend from group I to III was observed for RV lateral wall and septal systolic strain and strain rate (all p < 0.05). The LV but not RV size was significantly smaller in group I compared with group III (p < 0.05). Multiple regression identified duration of invasive ventilation (β = -0.66, p = 0.032) as an independent determinant of RV systolic strain after adjustment for perinatal risk factors.

CONCLUSION

Impairment of RV myocardial deformation occurs in children with BPD, the magnitude of which is associated negatively with the duration of invasive ventilation.

Novel Echocardiography Methods in the Functional Assessment of the Newborn Heart

Echocardiography in the neonatal intensive care unit has led to improvements in our ability to assess the neonatal heart in health and disease. Advances in neonatal cardiac imaging have provided the capability to obtain quantitative information that often supersedes the qualitative information provided by conventional methods. Novel quantitative measures of function include the assessment of the velocity of muscle tissue movement during systole and diastole using tissue Doppler velocity imaging, and evaluation of deformation and rotational characteristics of the myocardium utilizing speckle tracking echocardiography or tissue Doppler-derived strain imaging. A comprehensive understanding of these novel functional modalities, their predictive value, and limitations can greatly assist in managing both the normal and maladaptive responses in the newborn period. This article discusses the novel and emerging methods for assessment of left and right heart function in the neonatal population.

Pulmonary Hypertension and Vascular Abnormalities in Bronchopulmonary Dysplasia

Despite advances in the care of preterm infants, these infants remain at risk bronchopulmonary dysplasia (BPD), which results in prolonged need for supplemental oxygen, recurrent respiratory exacerbations, and exercise intolerance. Recent investigations have highlighted the important contribution of the developing pulmonary circulation to lung development, showing that these infants are also at risk for pulmonary vascular disease (PVD), including pulmonary hypertension (PH) and pulmonary vascular abnormalities. Several epidemiologic studies have delineated the incidence of PH in preterm infants and the impact on outcomes. These studies have also highlighted gaps in the understanding of PVD in BPD.

Perinatal inflammation: a common factor in the early origins of cardiovascular disease?

Cardiovascular disease continues to be the leading cause of global morbidity and mortality. Traditional risk factors account for only part of the attributable risk. The origins of atherosclerosis are in early life, a potential albeit largely unrecognized window of opportunity for early detection and treatment of subclinical cardiovascular disease. There are robust epidemiological data indicating that poor intrauterine growth and/or prematurity, and perinatal factors such as maternal hypercholesterolaemia, smoking, diabetes and obesity, are associated with adverse cardiovascular intermediate phenotypes in childhood and adulthood. Many of these early-life risk factors result in a heightened inflammatory state. Inflammation is a central mechanism in the development of atherosclerosis and cardiovascular disease, but few studies have investigated the role of overt perinatal infection and inflammation (chorioamnionitis) as a potential contributor to cardiovascular risk. Limited evidence from human and experimental models suggests an association between chorioamnionitis and cardiac and vascular dysfunction. Early life inflammatory events may be an important mechanism in the early development of cardiovascular risk and may provide insights into the associations between perinatal factors and adult cardiovascular disease. This review aims to summarise current data on the early life origins of atherosclerosis and cardiovascular disease, with particular focus on perinatal inflammation.

Serial assessment of right ventricular function using tissue Doppler imaging in preterm infants within 7 days of life

BACKGROUND

We aimed to evaluate right ventricular (RV) function longitudinally using tissue Doppler imaging (TDI) echocardiography in preterm infants.

METHODS

We selected 101 very-low-birth-weight (VLBW) infants for the study. Echocardiographic examinations including TDI were performed serially within 7days of life. Pulsed-Doppler TDI waveforms were recorded at the tricuspid valve annulus, and peak systolic velocities (Sa), early diastolic velocities (Ea), and late diastolic velocities (Aa) were measured.

RESULTS

Sa, Ea and Aa were all reduced significantly from 3h to 12h, and then increased gradually thereafter. These three velocities also increased with gestational age in the early neonatal period. The ratio of Ea to Aa (Ea/Aa) did not change significantly within the first week of life. The ratio of E to Ea (E/Ea) in VLBW infants also seemed to remain stable from birth to day 7. The values of Sa appeared to be associated with cardiac output in the early neonatal period. Both Sa and Aa in intubated infants were significantly higher than in non-intubated infants.

CONCLUSION

RV TDI velocities of preterm infants in the early neonatal period are influenced by gestational age, postnatal age, and respiratory status, although the RV E/Ea ratio appears to be almost stable throughout the neonatal period. Our findings may provide some basis for assessment of RV function in critically ill preterm infants.

B-type natriuretic peptide levels in preterm neonates with bronchopulmonary dysplasia: a marker of severity?

RATIONALE FOR THE STUDY

B type natriuretic peptide (BNP) is a hormone released in response to stretching of the ventricular wall. The role of BNP as a biomarker of bronchopulmonary dysplasia (BPD) has not been clarified.

OBJECTIVE

To determine if plasma BNP concentrations correlate with the severity of BPD.

METHODS

This prospective observational case control study included 60 preterm infants (≤32 weeks); 27 infants had no/mild BPD, 19 had moderate and 14 had severe BPD. BNP levels were measured at 36 ± 2 weeks PMA or within a week of discharge home. Groups were compared using Mann-Whitney's U-test, Kruskal-Wallis, and bivariate regression.

RESULTS

Median (IQR) plasma levels of BNP in infants with moderate/severe BPD infants (n = 33) were higher as compared to those with no/mild BPD (n = 27); 27.1 (12.1-43.5) pg/ml versus 9.3 (6-18.5) pg/ml; P < 0.05 (Mann Whitney U). Median (IQR) BNP levels in infants with severe BPD (n = 14), 43.5 (28.4-189) pg/ml differed significantly from levels in those with moderate (n = 19), 22.8 (10.3-27.7) pg/ml; mild (n = 16), 11.5 (6.6-44.5 pg/ml); or no (n = 11), 8.1 (5-12.6 pg/ml) BPD (P < 0.001 Kruskal-Wallis). Based on receiver operating characteristic curves, BNP > 24.4 pg/ml at 36 ± 2 weeks PMA or discharge home was 85.7% sensitive and 76.1% specific for severe BPD.

CONCLUSIONS

An elevation in plasma BNP was significantly associated with severe BPD. We speculate that plasma BNP measurement in infants with BPD may aid in risk-stratification and further targeted therapies.

Glucocorticoids and foetal heart maturation; implications for prematurity and foetal programming

Glucocorticoids are steroid hormones, essential in mammals to prepare for life after birth. Blood levels of glucocorticoids (cortisol in most mammals including humans; corticosterone in rats and mice) rise dramatically shortly before birth. This is mimicked clinically in the routine administration of synthetic glucocorticoids to pregnant women threatened by a preterm birth or to preterm infants to improve neonatal survival. Whilst effects on lung are well documented and essential for postnatal survival, those on heart are less well known. In this study, we review recent evidence for a crucial role of glucocorticoids in late gestational heart maturation. Either insufficient or excessive glucocorticoid exposure before birth may alter the normal glucocorticoid-regulated trajectory of heart maturation with potential life-long consequences.

Adverse perinatal environment contributes to altered cardiac development and function

Epidemiological observations report an association between intrauterine growth restriction (IUGR) and cardiovascular diseases. Systemic maternal inflammation is the most common stress during pregnancy, leading to IUGR. We hypothesized that perinatal inflammation and hyperoxygenation induce discernible alterations in cardiomyocyte contractility and calcium signaling, causing early cardiac dysfunction. Pregnant C3H/HeN mice were injected with LPS or saline on embryonic day 16. Newborn mice were placed in 85% O2 or room air (RA) for 14 days. Pups born to LPS-injected dams had reduced birth weight. Echocardiographic measurements revealed that in vivo LV function was compromised in LPS/O2 mice as early as 3 days of life. Isolated cardiomyocytes from LPS/O2 mice at day 14 exhibited decreased sarcomere fractional shortening, along with decreased time-to-90% peak shortening. Calcium transient amplitude was greatest in LPS/O2 mice. SERCA2a mRNA and protein levels were increased and phospholamban mRNA levels were decreased in LPS/O2 mice. Phosphorylation of phospholamban was increased, along with Sorcin mRNA levels in LPS/O2 mice. Combined exposure to perinatal inflammation and hyperoxia resulted in growth restriction, in vivo and in vitro cardiac dysfunction, coinciding with humans and animal models of cardiac dysfunction. Expression of calcium handling proteins during the neonatal period was similar to that observed during fetal stages of development. Our data suggest that perinatal inflammation and hyperoxia exposure alter fetal development, resulting in early cardiac dysfunction.

Pulmonary Hypertension in Preterm Infants with Bronchopulmonary Dysplasia

Bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, is a significant contributor to perinatal morbidity and mortality. Premature birth disrupts pulmonary vascular growth and initiates a cascade of events that result in impaired gas exchange, abnormal vasoreactivity, and pulmonary vascular remodeling that may ultimately lead to pulmonary hypertension (PH). Even infants who appear to have mild BPD suffer from varying degrees of pulmonary vascular disease (PVD). Although recent studies have enhanced our understanding of the pathobiology of PVD and PH in BPD, much remains unknown with respect to how PH should be properly defined, as well as the most accurate methods for the diagnosis and treatment of PH in infants with BPD. This article will provide neonatologists and primary care providers, as well as pediatric cardiologists and pulmonologists, with a review of the pathophysiology of PH in preterm infants with BPD and a summary of current clinical recommendations for managing PH in this population.

Echocardiography in pediatric pulmonary hypertension

Pulmonary hypertension (PH) can be a rapidly progressive and fatal disease. Although right heart catheterization remains the gold standard in evaluation of PH, echocardiography remains an important tool in screening, diagnosing, evaluating, and following these patients. In this article, we will review the important echocardiographic parameters of the right heart in evaluating its anatomy, hemodynamic assessment, systolic, and diastolic function in children with PH.

Looking beyond PPHN: the unmet challenge of chronic progressive pulmonary hypertension in the newborn

Abstract Infants with forms of pulmonary hypertension (PH) that persist or develop beyond the first week of life are an understudied group of patients with up to 40%-60% mortality. The clinical management of the progressive PH that develops in these infants is challenging because of the nonspecific signs and symptoms of clinical presentation, the limited diagnostic sensitivity of standard echocardiographic techniques, and the lack of proven therapies. The signaling mechanisms that underlie the structural and functional abnormalities in the pulmonary circulation of these infants are not yet clear. The ability to improve outcomes for these patients awaits technological advances to improve diagnostic capabilities and therapeutic discoveries made in basic science laboratories that can be tested in randomized clinical trials.

The efficacy of cardiac findings in assessing the outcome in preterms with bronchopulmonary dysplasia

OBJECTIVES

To evaluate if cardiac dysfunctions are important in assessing the outcome in newborns with Bronchopulmonary Dysplasia (BPD), by evaluating cardiac functions with N-terminal prohormone of brain natriüretic peptide (NT-proBNP) levels, M-mode and tissue doppler echocardiography at 6-12 mo of age.

METHODS

Twenty eight patients were retrospectively classified as mild, moderate and severe according to the diagnostic criterias for BPD. All cases were assessed with standard M-mode, tissue doppler echocardiography and NT-proBNP levels. Control group consisted of 28 healthy infants, having similar postnatal ages as patients and were assessed with standard M-mode and tissue doppler echocardiography.

RESULTS

The age of patients with BPD was 9.8 ± 2.3 mo and control group was 9.5 ± 2.6 mo. There was no significant difference between the postnatal ages of two groups (p > 0.05). Neither pulmonary hypertension nor pulmonary/tricuspid regurgitation was detected. The M-mode echocardiography measurements did not differ between patients and control group (p > 0.05). Tissue doppler echocardiography, tricuspid valve medial segment early diastolic myocardial relaxation velocity (TME') measurements of patients were found significantly lower, peak transtricuspid filling velocity in the early diastole (TE)/TME' ratios and isovolumetric relaxation time (IVRT) measurements were found significantly higher than control group (p < 0.05). Tricuspid E, TE/TLE' (Tricuspid valve lateral segment early diastolic myocardial relaxation velocity), TE/RVLE'(Right ventricular lateral segment early diastolic myocardial relaxation velocity), TE/TME' levels were also found as significantly abnormal in patients with severe BPD. A significant correlation was found between right ventricular diastolic disfunctions and severity of BPD (p < 0.05). No statistically significant difference was found between NT-proBNP levels, BPD stages and tissue doppler echocardiography measurements (p > 0.05).

CONCLUSIONS

This is the first study evaluating cardiac findings in patients with BPD by tissue doppler echocardiography and NT-proBNP at the same time. On the basis of cardiac evaluations, tissue doppler echocardiography measurements were found as significant and specific for the early assessment of right ventricular diastolic disfunctions.

Serial assessment of left-ventricular function using tissue Doppler imaging in premature infants within 7 days of life

Although many echocardiographic parameters can assess cardiac function noninvasively in preterm infants, it has not been determined what indices are the best. We assessed left-ventricular performance in 101 very low-birth weight (VLBW) infants using tissue Doppler imaging (TDI) echocardiography. Echocardiographic examinations, including TDI, were performed serially within 7 days of life. Pulsed-Doppler TDI waveforms were recorded at the mitral valve annulus, and peak systolic velocities (Sa), early diastolic velocities (Ea), and late diastolic velocities (Aa) were measured. Sa and Aa velocities were both decreased significantly from 3 to 12 h and then gradually increased. Ea velocities showed no significant, longitudinal changes, but Ea values in premature groups appeared to be significantly lower than those in mature groups. The ratio of E to Ea (E/Ea) of VLBW infants seemed to be almost stable from birth to day 7, and this also showed no significant differences between different gestational age groups. E/Ea values in infants with patent ductus arteriosus (PDA) appeared to be greater than those in non-PDA infants. Our present findings suggest that TDI assessment in the early neonatal period might be useful in detecting latent systolic/diastolic failure of critically ill preterm infants.

Cardiovascular consequences of bronchopulmonary dysplasia in prematurely born preschool children

BACKGROUND

A limited number of studies have reported various short-term cardiovascular changes in bronchopulmonary dysplasia (BPD) patients in the postsurfactant era. Little is known about the course of these changes in children with BPD.

OBJECTIVES

It was the aim of this study to investigate cardiovascular consequences of BPD at preschool ages and to find out possible risk factors related to cardiovascular sequelae.

METHODS

Prematurely born children with (n = 21) and without BPD (n = 20) were evaluated with conventional and myocardial tissue Doppler echocardiography at the age of 2-4 years.

RESULTS

BPD patients had a decreased pulmonary artery acceleration time and higher left and right ventricular myocardial performance indexes, consistent with higher pulmonary pressures and impaired biventricular systolic and diastolic functions at preschool ages. Low birth weight, disease severity and postnatal cumulative steroid dose were related to these changes.

CONCLUSION

Negative effects of BPD on global cardiac performances of both ventricles and pulmonary arterial pressure persist up to preschool ages.

Persistently elevated right ventricular index of myocardial performance in preterm infants with incipient bronchopulmonary dysplasia

OBJECTIVES

Elevated pulmonary vascular resistance occurs during the first days after birth in all newborn infants and persists in infants at risk for bronchopulmonary dysplasia (BPD). It is difficult to measure in a non-invasive fashion. We assessed the usefulness of the right ventricular index of myocardial performance (RIMP) to estimate pulmonary vascular resistance in very low birth weight infants.

STUDY DESIGN

Prospective echocardiography on day of life (DOL) 2, 7, 14, and 28 in 121 preterm infants (median [quartiles] gestational age 28 [26]-[29] weeks, birth weight 998 [743-1225] g) of whom 36 developed BPD (oxygen supplementation at 36 postmenstrual weeks).

RESULTS

RIMP derived by conventional pulsed Doppler technique was unrelated to heart rate or mean blood pressure. RIMP on DOL 2 was similar in infants who subsequently did (0.39 [0.33-0.55]) and did not develop BPD (0.39 [0.28-0.51], p = 0.467). RIMP declined steadily in non-BPD infants but not in BPD infants (DOL 7: 0.31[0.22-0.39] vs. 0.35[0.29-0.48], p = 0.014; DOL 14: 0.23[0.17-0.30] vs. 0.35[0.25-0.43], p<0.001; DOL 28: 0.21[0.15-0.28] vs. 0.31 [0.21-0.35], p = 0.015).

CONCLUSIONS

In preterm infants, a decline in RIMP after birth was not observed in those with incipient BPD. The pattern of RIMP measured in preterm infants is commensurate with that of pulmonary vascular resistance.

Echocardiographic evaluation of the single right ventricle in congenital heart disease: results of new techniques

Right ventricular (RV) function is increasingly recognized as having prognostic significance in various disease processes. The current gold standard for noninvasive measurement of RV function is cardiac magnetic resonance imaging; however, because of practical considerations, echocardiography remains the most often used modality for evaluating the RV. In the past, because of its complex morphology, echocardiographic assessment of the RV was usually qualitative in nature. Current advances in echocardiographic techniques have been able to overcome some of the previous limitations and thus quantification of RV function is increasingly being performed. In addition, recent echocardiographic guidelines for evaluating the RV have been published to aid in standardizing practice. The evaluation of RV function almost certainly has no greater importance than in the congenital heart population, especially in those patients that have a single RV acting as the systemic ventricle. As this complex population continues to increase in number, accurate and precise evaluation of RV function will be a major issue in determining clinical care.

Echocardiographic detection of pulmonary hypertension in extremely low birth weight infants with bronchopulmonary dysplasia requiring prolonged positive pressure ventilation

OBJECTIVE

The goal of this study was to delineate the epidemiology of echocardiographically diagnosed pulmonary hypertension (PH) in extremely low birth weight (ELBW) infants with bronchopulmonary dysplasia (BPD) requiring prolonged positive pressure ventilation (PPV), and to determine the independent relationship between PH and mortality in these patients.

STUDY DESIGN

Our retrospective cohort included ELBW infants, with BPD requiring prolonged PPV, hospitalized in Cincinnati, Ohio during 2003-2009, as recorded in the National Institute of Child Health and Human Development Neonatal Research Network Database. Following chart review, a logistic regression model was constructed to understand the contribution of PH to mortality in infants with BPD requiring prolonged PPV.

RESULT

We identified 216 patients (19%) with BPD requiring prolonged PPV among 1156 ELBW infants. Of these patients, 41% received echocardiography after 4 weeks of life, with 37% showing evidence of PH. Logistic regression analysis demonstrated that infants with BPD requiring prolonged PPV, with PH detectable by echocardiogram, were four times more likely to die (adjusted odds ratio): 4.6, 95% confidence interval: 1.3-16.5) when compared with infants with BPD requiring prolonged PPV without echocardiographic evidence of PH.

CONCLUSION

Pulmonary hypertension appears to be an important, independent determinant of death in infants with BPD requiring prolonged PPV.

Maternal inflammation, growth retardation, and preterm birth: insights into adult cardiovascular disease

The "fetal origin of adult disease Hypothesis" originally described by Barker et al. identified the relationship between impaired in utero growth and adult cardiovascular disease risk and death. Since then, numerous clinical and experimental studies have confirmed that early developmental influences can lead to cardiovascular, pulmonary, metabolic, and psychological diseases during adulthood with and without alterations in birth weight. This so called "fetal programming" includes developmental disruption, immediate adaptation, or predictive adaptation and can lead to epigenetic changes affecting a specific organ or overall health. The intrauterine environment is dramatically impacted by the overall maternal health. Both premature birth or low birth weight can result from a variety of maternal conditions including undernutrition or dysnutrition, metabolic diseases, chronic maternal stresses induced by infections and inflammation, as well as hypercholesterolemia and smoking. Numerous animal studies have supported the importance of both maternal health and maternal environment on the long term outcomes of the offspring. With increasing rates of obesity and diabetes and survival of preterm infants born at early gestational ages, the need to elucidate mechanisms responsible for programming of adult cardiovascular disease is essential for the treatment of upcoming generations.

Myocardial performance in asphyxiated full-term infants assessed by Doppler tissue imaging

The aim of this study was to assess myocardial performance of full-term infants with perinatal asphyxia using Doppler tissue imaging (DTI) and to correlate it with serum cardiac troponin T (cTnT) concentrations. Twenty-five asphyxiated and 20 nonasphyxiated term infants were investigated. Serum cTnT concentrations were measured between 12 and 24 h of life. Conventional two-dimensional Doppler echocardiography and DTI were done during the first 72 h of life. Right ventricular (RV) and left ventricular (LV) Tei indexes were significantly higher in asphyxiated neonates (mean +/- SD: 0.45 +/- 0.05 vs. 0.28 +/- 0.05, P < 0.001 and 0.51 +/- 0.04 vs. 0.38 +/- 0.04, P < 0.001, respectively). Mitral and tricuspid systolic (Sm) velocities were significantly lower in asphyxiated neonates (mean +/- SD: 5.06 +/- 0.89 vs. 6.89 +/- 0.94 cm/s, P < 0.001 and 5.78 +/- 0.58 vs. 6.69 +/- 0.87 cm/s, P < 0.001, respectively). cTnT concentrations were significantly higher in asphyxiated neonates [median (range): 0.17 (0.05-0.23) vs. 0.03 (0-0.07) microg/l, P < 0.001)], and they correlated positively with the LV Tei index (r = 0.67, P < 0.001) and the RV Tei index (r = 0.68, P < 0.001) and negatively with the mitral systolic (Sm) velocity (r = -0.68, P < 0.001) and tricuspid systolic (Sm) velocity (r = -0.41, P = 0.01). A higher cTnT was a significant predictor of mortality, whereas fractional shortening (FS) and DTI measurements did not show any significant predictive value. The DTI technique appears to be more sensitive than conventional echocardiography in the early detection of myocardial dysfunction induced by perinatal asphyxia in full-term infants.