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

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.

Early diastolic dysfunction and respiratory morbidity in premature infants: an observational study

OBJECTIVE

To test if diastolic dysfunction measured on day one of age is associated with the need for invasive ventilation in preterm infants.

STUDY DESIGN

We conducted a retrospective observational tissue Doppler echocardiographic study over the first 12 h of age for infants born <32 weeks who were invasively ventilated, and infants on continuous positive pressure ventilation (CPAP).

RESULTS

One hundred and eighty-three infants were included (27 ± 2 weeks and 999 ± 296 g). Invasively ventilated infants [(n = 96 (53%)] had lower left ventricular (LV) e' (3.4 ± 1.0 vs. 4.1 ± 1.5 cm/s, p < 0.01) and lower LV ea' ratio (0.8 ± 0.2 vs. 1.0 ± 0.4, p < 0.01), even after adjusting for common neonatal confounders (LV e' adjusted OR 0.62, 95% CI 0.45 - 0.87, p < 0.01; LV ea' adjusted OR 0.14, 95% CI 0.03-0.68, p = 0.01).

CONCLUSION

LV diastolic dysfunction is independently associated with a higher risk for invasive ventilation on day one of age.

C.10BreatnachC. R.11BreindahlM12DempseyE13GrovesA. M.14GuptaS15Horsberg EriksenB16LevyP. T.1718McNamaraP. J.19MolnarZ20RogersonS. R.21RoehrC. C.22SavoiaM23SchwarzC. E.24SehgalA25SinghY26SliekerM. G.27TissotC28van der LeeR29van LaereD30van OvermeireB31van WykL32. 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.

How to assess hemodynamic status in very preterm newborns in the first week of life?

BACKGROUND

Assessing hemodynamic status in preterm newborns is an essential task, as many studies have shown increased morbidity when hemodynamic parameters are abnormal. Although oscillometric monitoring of arterial blood pressure (BP) is widely used due to its simplicity and lack of side effects, these values are not always correlated with microcirculation and oxygen delivery.

OBJECTIVES

This review focuses on different tools for the assessment of hemodynamic status in preterm newborns. These include the measurement of clinical (BP, capillary refill time and urinary output (UO)) or biological parameters (lactate analysis), functional echocardiography, and near-infrared spectroscopy (NIRS). We describe the concepts and techniques involved in these tools in detail, and examine the interest and limitations of each type of assessment.

CONCLUSIONS

This review highlights the complementarities between the different parameters used to assess hemodynamic status in preterm newborns during the first week of life. The analysis of arterial BP measured by oscillometric monitoring must take into account other clinical data, in particular capillary refill time and UO, and biological data such as lactate levels. Echocardiography improves noninvasive hemodynamic management in newborns but requires specific training. In contrast, NIRS may be useful in monitoring the clinical course of infants at risk of, or presenting with, hypotension. It holds the potential for early and noninvasive identification of silent hypoperfusion in critically ill preterm infants. However, more data are needed to confirm the usefulness of this promising tool in significantly changing the outcome of these infants.

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.

Clinical utility of right ventricular fractional area change in preterm infants

INTRODUCTION

Right ventricular fractional area change (RV FAC) is a novel non-invasive quantitative measure of RV function. Reference values of RV FAC and RV end systolic and diastolic areas (RVEDA, RVESA) have recently been established in preterm infants, but their role as marker to assess the efficacy of patient management strategies in the first week of life is largely unknown. The aims of this study were to assess the relationship between RV FAC and gestational age/birthweight, assess the RV FAC on day one of age to predict the later evolution of peri/intraventricular haemorrhage (P/IVH), and assess the influence of a persistent patent ductus arteriosus (PDA) on RV FAC during the first week of age.

METHODS

Preterm infants <29 weeks gestation underwent echocardiography assessments on days 1, 2 and 5-7. RVEDA and RVESA were traced in the RV-focused apical four-chamber view, and RV FAC was calculated using the formula [(RVEDA-RVESA)÷(RVEDA)] × 100. PDA treatment was not carried out during the study period. A cranial ultrasound was carried out on all infants on Days 5-7 of age. P/IVH was defined as IVH grades II to IV.

RESULTS

One hundred and one infants with a mean gestation of 26.5 (1.4) weeks and a birthweight of 983 (240) grams were enrolled in the study. There was no relationship between RV FAC and birthweight (r=-0.02, p=0.86) but there was a negative correlation between RV FAC and echo-measured SVR (r=-0.57, p<0.001). On Day 1, RV FAC was lower in infants who developed P/IVH (24% [18-34] vs. 31% [25-40], p=0.04). On Days 5-7 infants with a PDA had a lower RV FAC compared with those without [42 (7) vs. 49 (9) %, p<0.001].

CONCLUSION

RV FAC may be a useful addition to the haemodynamic assessment of preterm infants during the first week of age.