Echocardiographic evaluation of left atrial volume and comparative analysis to left atrial to aortic root ratio in premature neonates and infants with patent ductus arteriosus.

PURPOSE: Left atrium to aortic root ratio (LA/Ao) is an echocardiographic marker of hemodynamically significant patent ductus arteriosus (PDA). Since 2-dimensional measurement of the ratio is geometrically limited, left atrial volume (LAV) which has 3-dimensional characteristics was investigated. The aim of this study was to determine a correlation between LA/Ao ratio and LAV as well as holodiastolic flow reversal in preterm neonates with and without a PDA. METHODS: A retrospective evaluation of neonates with and without PDA was performed. Targeted neonatal echocardiography evaluation of LA/Ao and LAV was measured from parasternal long-axis view and the apical 4 and 2-chamber views, respectively. Univariate and linear regression analysis were performed. RESULTS: 200 patients were included of whom 158 (79.0%) had a PDA shunt. The median gestational age at the time of echo was 27.4 weeks (IQR: 25.7-29.4 weeks). The median LA/Ao ratio was 1.51 (IQR: 1.26-1.83) and median LAV indexed to weight was  .91 mL/kg (IQR: .65-1.18 mL/kg). There was a significant correlation between LA/Ao and LAV indexed to weight in the PDA group (r2 = .080, p = .0003). LA/Ao ratio and LAV indexed to weight differed significantly between those with diastolic flow reversal versus no-flow reversal (LA/Ao, p = .003; LAV, p = .001). CONCLUSIONS: This study demonstrated a significant correlation between LA/Ao and LAV in preterm infants with PDA, with greater magnitude of discordance for LAV. The power of LAV versus LA/Ao in monitoring hemodynamically significant PDA requires prospective evaluation.

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.

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.

Shape of Pulmonary Artery Doppler Flow Profile and Right Ventricular Hemodynamics in Neonates.

OBJECTIVES: To characterize pulmonary artery Doppler flow profile (PAFP) patterns among infants receiving care in neonatal intensive care units and to examine the association of PAFP patterns with pulmonary and right ventricular (RV) hemodynamics. STUDY DESIGN: This is a retrospective study at 2 tertiary intensive care units over 4 years that included neonates who demonstrated a complete tricuspid regurgitation envelope on targeted neonatal echocardiography. Separate personnel reviewed TNEs to characterize PAFP patterns, divide cohort into PAFP groups, and measure quantitative indices of RV hemodynamics (RV systolic pressure, pulmonary artery acceleration time and its ratio with RV ejection time, tricuspid annular plane systolic excursion, and RV output), for intergroup comparisons. RESULTS: We evaluated TNEs from 186 neonates with median gestational age of 28.5 weeks (IQR, 25.9-35.9 weeks). Four distinct PAFP patterns were identified (A) near-isosceles triangle (22%), (B) right-angled triangle (29%), (C) notching (40%), and (D) low peak velocity (<0.4 m/s; 9%). Groups A-C demonstrated a stepwise worsening in all indices of PH, whereas pattern D was associated with lower tricuspid annular plane systolic excursion and RV output. Using common definitions of pulmonary hypertension (PH), pattern A performed best to rule out PH (sensitivity range, 81%-90%) and pattern C for diagnosing PH (specificity range, 63%-78%). CONCLUSIONS: Inspection of PAFP is a simple bedside echocardiography measure that provides clinically meaningful information on underlying RV hemodynamics and may aid in screening and monitoring of patients for PH in intensive care units.

Hemodynamic evaluation of extremely low birth weight infants during the first 7 days of life.

BACKGROUND AND AIM: We aimed to investigate the hemodynamic status of extremely low birth weight (ELBW) infants during the transitional period under intensive management. METHODS: This retrospective cohort study analyzed left ventricular ejection fraction (LVEF), left ventricular end-systolic wall stress (ESWS), left ventricular internal dimension in diastole (LVIDd), and mean arterial pressure (MAP) of ELBW infants during their first week of life. Small for gestational age (SGA), histological chorioamnionitis (hCAM), severe intraventricular hemorrhage (IVH), and non-survival to discharge infants were compared to their counterparts. RESULTS: Sixty-two infants (25.7 ± 2.1 weeks, 700.7 ± 165.4 g) were analyzed. MAP gradually increased. Median LVEF was 69.8 % on day 1, decreased to 62.7 % on day 2, then increased throughout the week. ESWS was lowest at birth, rose to 28.2 g/cm2 on day 2, and decreased on day 6. There were no significant changes in LVIDd. SGA infants had higher MAP throughout, higher LVEF on day 2 and 3, but lower LVEF on day 5 to 7. LVIDd was lower in hCAM group. Severe IVH group had a more significant drop in LVEF on day 2, higher ESWS, and a higher incidence of hemodynamic significant patent ductus arteriosus (hsPDA). Non-survival had lower LVIDd. CONCLUSIONS: MAP increased gradually. Hemodynamic instability was observed in the first two days, with decreased LVEF and increased ESWS before stabilization. We observed an alteration in hemodynamic adaptation in SGA and hCAM infants. Severe IVH group experienced early hemodynamic instability and a higher incidence of hsPDA.

Growth of targeted neonatal echocardiography in Chinese neonatal intensive care units: gaps in practice and training.

To evaluate clinical practice, neonatologists' attitudes, and the extent of training and accreditation regarding targeted neonatal echocardiography (TnEcho) among Chinese neonatologists. A web-based questionnaire was emailed to 331 neonatologists across China who completed training in subspecialty neonatology. The survey covered various aspects of TnEcho, including the characteristics of clinical practice, attitudes towards its usefulness, and perceived barriers to implementation and training methods. Survey response rate was 68.0% (225/331). Seventy-nine (35.1%) respondents stated that TnEcho was utilized in their NICUs. Most respondents reported the use of echocardiography to evaluate hemodynamic significance of the patent ductus arteriosus (PDA, 94.9%). The eyeballing technique was most used to evaluate left (82.3%) and right (77.2%) ventricular function. Most respondents (87.3-96.2%) positively valued the role of TnEcho in providing timely and longitudinal hemodynamic information to guide cardiovascular care. Access to TnEcho was more likely in centers with on-site pediatric cardiology service (p = .003), larger bed capacity (p = .004), or level IV status (p = .003). Lack of experienced practitioners with echocardiography expertise (88.9%) and accredited training programs (85.8%) was perceived to be the major barrier to implementation. Of concern, most practitioners with TnEcho skills received training in an informal manner through workshops (60.8%) or self-directed learning (54.4%). Conclusions: The use of TnEcho for longitudinal evaluation of infants with hemodynamic instability is growing within Chinese NICUs. There is an urgent need to develop standardized training programs and accreditation for TnEcho which are adapted to the Chinese context.

Impact of Early Hemodynamic Screening on Extremely Preterm Outcomes in a High-Performance Center.

Rationale: Increasing survival of extremely preterm infants with a stable rate of severe intraventricular hemorrhage represents a growing health risk for neonates. Objectives: To evaluate the role of early hemodynamic screening (HS) on the risk of death or severe intraventricular hemorrhage. Methods: All eligible patients 22-26+6 weeks' gestation born and/or admitted <24 hours postnatal age were included. As compared with standard neonatal care for control subjects (January 2010-December 2017), patients admitted in the second epoch (October 2018-April 2022) were exposed to HS using targeted neonatal echocardiography at 12-18 hours. Measurements and Main Results: A primary composite outcome of death or severe intraventricular hemorrhage was decided a priori using a 10% reduction in baseline rate to calculate sample size. A total of 423 control subjects and 191 screening patients were recruited with a mean gestation and birth weight of 24.7 ± 1.5 weeks and 699 ± 191 g, respectively. Infants born at 22-23 weeks represented 41% (n = 78) of the HS epoch versus 32% (n = 137) of the control subjects (P = 0.004). An increase in perinatal optimization (e.g., antepartum steroids) but with a decline in maternal health (e.g., increased obesity) was seen in the HS versus control epoch. A reduction in the primary outcome and each of severe intraventricular hemorrhage, death, death in the first postnatal week, necrotizing enterocolitis, and severe bronchopulmonary dysplasia was seen in the screening era. After adjustment for perinatal confounders and time, screening was independently associated with survival free of severe intraventricular hemorrhage (OR 2.09, 95% CI [1.19, 3.66]). Conclusions: Early HS and physiology-guided care may be an avenue to further improve neonatal outcomes; further evaluation is warranted.

Management of neonatal pulmonary hypertension-a survey of neonatal intensive care units in India.

BACKGROUND: Persistent pulmonary hypertension of the newborn (PPHN) is a common neonatal condition associated with significant morbidity and mortality. First-line diagnostic and treatment options such as echocardiography and inhaled nitric oxide (iNO) are not routinely available in resource limited settings and alternative treatment modalities need to be utilized. This study was conducted to assess current diagnostic and management strategies used for PPHN in Indian neonatal intensive care units (NICUs). METHODS: A questionnaire in multiple choice question format was sent to practising neonatologists in India via an online survey tool between July to August 2021. Information pertaining to demographic data, diagnostic criteria and management strategies of PPHN was requested. The responses were collated and information processed. RESULTS: There were 118 respondent NICUs (response rate 74%). The majority of neonatal units (65%) admitted an average of 1-3 patients of PPHN per month. Targeted neonatal echocardiography (TnECHO) was practised in 80% of the units. Most common management strategies being followed were pulmonary vasodilators (88.1%), inotropes (85.6%), conventional ventilation (68.6%) and high frequency ventilation (59.3%). The most preferred pulmonary vasodilator was sildenafil (79%) and inotropic agent was milrinone (32%). Only 25% of respondents reported use of iNO. None of the participating units used extracorporeal membrane oxygenation. CONCLUSION: We found wide variability in management practices of PPHN across Indian NICUs. Non-selective pulmonary vasodilators are more widely used than iNO. There is an urgent need for structured TnECHO training programs and evidence based national guidelines for standardized management of PPHN as per availability of resources in India. Additional research on low cost alternative therapies to iNO in Indian settings might be helpful.

Targeted neonatal echocardiography and lung ultrasound in preterm infants with chronic lung disease with and without pulmonary hypertension, screened using a standardized algorithm.

Introduction: Increased recognition of the development of chronic pulmonary hypertension (cPH) in preterm infants with chronic lung disease (CLD) has prompted enhanced monitoring for the identification of different phenotypes. Methods: All newborns consulted for oxygen/respiratory support dependency (CLD assessment) from January 2018 to December 2021 were included. TnECHO and LUS screening for cPH-CLD were performed at 36 weeks postmenstrual age. Cases of cPH related to increased pulmonary blood flow (cPH-IPBF) were referred to Pediatric Cardiology. The objective of the study was to identify all cases of cPH (cPH-CLD/IPBF) in the CLD patients screened and to compare outcomes. Following a standardized algorithm, cPH-CLD patients were treated with diuretics; ultrasounds taken before and after treatment were analyzed. Results: Seventy-two patients with CLD were screened. Twenty-two (30%) had cPH-CLD, and nine (12%) had cPH-IPBF. cPH infants underwent more days of mechanical ventilation, were more likely to have retinopathy of prematurity, and showed increased mortality. The LUS pattern observed in the 72 CLD patients consisted of a thickened pleural line and a B-line interstitial heterogeneous pattern; 29% of patients were found to have lung consolidations. After diuretic therapy, step-down in respiratory support occurred in 59% of neonates with cPH-CLD. A decrease in respiratory rate (RR), right ventricular output (RVO), markers of pulmonary vascular resistance (PVR), and B-line pattern was observed. In tissue Doppler imaging, biventricular diastolic function was found to be modified after diuretics. Conclusions: CLD infants with cPH showed increased morbidity and mortality. In cPH-CLD patients, a decrease in RR and step-down in respiratory support was observed after diuretic treatment. Follow-up ultrasound showed a decrease in RVO, markers of PVR, and B-lines.

Impact of early screening echocardiography and targeted PDA treatment on neonatal outcomes in "22-23" week and "24-26" infants.

The hemodynamically significant patent ductus arteriosus (hsPDA) is a controversial topic in neonatology, particularly among neonates at the earliest gestational ages of 22+0-23+6 weeks. There is little, to no data on the natural history or impact of the PDA in extremely preterm babies. In addition, these high-risk patients have typically been excluded from randomized clinical trials of PDA treatment. In this work, we present the impact of early hemodynamic screening (HS) of a cohort of patients born 22+0-23+6 weeks gestation who either were diagnosed with hsPDA or died in the first postnatal week as compared to a historical control (HC) cohort. We also report a comparator population of 24+0-26+6 weeks gestation. All patients in the HS epoch were evaluated between 12-18h postnatal age and treated based on disease physiology whereas the HC patients underwent echocardiography at the discretion of the clinical team. We demonstrate a two-fold reduction in the composite primary outcome of death prior to 36 weeks or severe BPD and report a lower incidence of severe intraventricular hemorrhage (n=5, 7% vs n=27, 27%), necrotizing enterocolitis (n=1, 1% vs n=11, 11%) and first-week vasopressor use (n=7, 11% vs n=40, 39%) in the HS cohort. HS was also associated with an increase in survival free of severe morbidity from the already high rate of 50% to 73% among neonates <24 weeks gestation. We present a biophysiological rationale behind the potential modulator role of hsPDA on these outcomes and review the physiology relevant to neonates born at these extremely preterm gestations. These data highlight the need for further interrogation of the biological impact of hsPDA and impact of early echocardiography directed therapy in infants born less than 24 weeks gestation.

Use of Cardio-Pulmonary Ultrasound in the Neonatal Intensive Care Unit.

Cardiopulmonary ultrasound (CPUS), the combination of lung ultrasound (LUS) and targeted neonatal echocardiography (TnECHO)AA, may offer a more appropriate approach to the challenging neonatal cardiovascular and respiratory disorders. This paper reviews the possible use of CPUS in the neonatal intensive care unit (NICU).

Cardiopulmonary Ultrasound Patterns of Transient Acute Respiratory Distress of the Newborn: A Retrospective Pilot Study.

Acute transient respiratory distress in the first hours of life is usually defined as transient tachypnea of the newborn (TTN). TTN is a respiratory self-limiting disorder consequent to delayed lung fluid clearance at birth. While TTN is the most common etiology of respiratory distress near term, its pathogenesis and diagnostic criteria are not well-defined. Lung ultrasound and targeted neonatal echocardiography are increasingly being used to assess critically ill infants, although their combined use to improve diagnostic precision in neonatal intensive care units has not yet been described. This retrospective pilot analysis aimed to identify possible cardiopulmonary ultrasound (CPUS) patterns in term and late preterm infants suffering from transient respiratory distress and requiring non-invasive respiratory support. After retrospectively revising CPUS images, we found seven potential sonographic phenotypes of acute neonatal respiratory distress. Up to 50% of the patients presented with signs of increased pulmonary vascular resistance, suggesting that those patients may be diagnosed with mild forms of persistent pulmonary hypertension of the newborn. Approximately 80% of the infants with a history of meconium-stained amniotic fluid displayed irregular atelectasis, indicating that they may have suffered from mild meconium aspiration syndrome. CPUS evaluation may improve accuracy in the approach to the infants presenting with transient acute respiratory distress, supporting communication with the parents and carrying important epidemiological consequences.

Normal values for superior vena cava flow in preterm neonates using a new echocardiographic approach.

OBJECTIVE: Recently, a novel approach to imaging Superior Vena Cava (SVC) flow has been presented, showing better repeatability and better agreement with MRI-derived SVC flow measures. The objective was to establish normal values of SVC flow with the novel approach in the first 48 h of life. STUDY DESIGN: This was a prospective, observational study. All infants with gestational age (GA) less than 31 weeks were eligible. Echocardiographic evaluation was performed at 5, 12, 24, 48 h of postnatal life. A subgroup of uncomplicated infants was studied to define a normal range for SVC flow. RESULTS: Forty-five infants were enrolled. We estimated normative values in a subgroup of 31 uncomplicated infants. The median SVC flow significantly increases from 83 ml/kg/min at 5 h of life to 153 ml/kg/min at 48 h (p < .001). CONCLUSION: Using the novel approach we derived normal values of SVC flow in a cohort of uncomplicated preterm population at high risk for developing IVH.

How to diagnose and treat acute pulmonary hypertension when you have no cardiology support.

Acute pulmonary hypertension (aPH) is a complex, physiology-driven disorder that causes critical illness in newborns, the hallmark of which is elevated pressure in the pulmonary vascular bed. Several underlying hemodynamic phenotypes exist, including classic arterial aPH with resistance-driven elevations in pulmonary arterial pressure (PAP), alongside flow-driven aPH from left-to-right shunt lesions, and primary left ventricular dysfunction with pulmonary venous hypertension and elevated left atrial pressure. Targeted neonatal echocardiography (TnECHO) is an important tool for evaluation of hemodynamics in aPH and is highly useful for evaluating modulators of disease and targeting cardiovascular therapy. The diagnostic approach to aPH includes confirmation of elevation of PAP, evaluation of the cause and exclusion of structural cardiac disease, assessment of the response of the myocardium to adverse loading conditions, and appraisal of the adequacy of systemic blood flow. Therapeutic goals include support of right ventricular (RV) function, RV afterload reduction, and selection of cardiotropic agents that support underlying pathophysiology without adverse effects on heart rate or pulmonary vascular resistance in addition to routine supportive intensive care. Training programs for TnECHO exist across multiple jurisdictions and strong correlation with pediatric cardiology assessment has been demonstrated. Future directions include adapting TnECHO training with a greater focus on achieving competency, and further research into the role of the modality in providing individualized cardiovascular care for patients with heterogenous underlying physiology, and its effect on key neonatal outcomes.

Management of cardiac dysfunction in neonates with pulmonary hypertension and the role of the ductus arteriosus.

Pulmonary hypertension in the neonate is associated with cardiopulmonary disturbances and neurodevelopment morbidity. The patent ductus arteriosus is a persistent fetal shunt that can be pathologic vs supportive in the setting of neonatal pulmonary hypertension. Understanding the underlying pathophysiology of pulmonary hypertension and the cardiopulmonary effects of various phenotypes can guide management in this vulnerable population. In this narrative, we will summarize the physiologic principles of pulmonary hypertension, the impact of the patent ductus arteriosus on various phenotypes, and the utility of serial targeted neonatal echocardiography to individualize clinical assessment and management.

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

Diastolic dysfunction often complicates myocardial ischemia with increased mortality rates. However, less is known about diastolic function after perinatal asphyxia in neonates with hypoxic-ischemic encephalopathy (HIE) during therapeutic hypothermia (TH) and rewarming. Aim: The aim of this study was to assess diastolic function with tissue Doppler imaging (TDI) in neonates with moderate-severe HIE during TH and rewarming. Method: Newborns at >36 weeks' gestation with moderate-severe HIE treated with TH were evaluated with targeted neonatal echocardiography (TNE), including TDI, within 24 h of TH initiation (T1), at 48-72 h of treatment (T2), and after rewarming (T3). These retrospective data were collected and compared with a control group of healthy babies at >36 weeks' gestation that was prospectively evaluated following the same protocol. Results: A total of 21 patients with HIE + TH and 15 controls were included in the study. Myocardial relaxation before the onset of biventricular filling was prolonged in the HIE + TH group during TH with significantly longer isovolumic relaxation time (IVRT') in the left ventricle (LV), the septum, and the right ventricle (RV). This was associated with slower RV early diastolic velocity (e') and prolonged filling on T1. Total isovolumic time (t-IVT; isovolumic contraction time [IVCT'] + IVRT') and myocardial performance index (MPI') were globally increased in asphyxiated neonates. All these differences persisted after correction for heart rate (HR) and normalized after rewarming. TDI parameters assessing late diastole (a' velocity or e'/a' and E/e' ratios) did not differ between groups. Conclusion: TDI evaluation in our study demonstrated a pattern of early diastolic dysfunction during TH that normalized after rewarming, whereas late diastole seemed to be preserved. Our data also suggest a possible involvement of impaired twist/untwist motion and dyssynchrony. More studies are needed to investigate the impact and therapeutic implication of diastolic dysfunction in these babies, as well as to clarify the role of TH in these findings.

Neonatologist Performed Echocardiography for Evaluating the Newborn Infant.

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