Noninvasive Assessment of Myocardial Work in Children.

The noninvasive assessment of ventricular function is an ongoing challenge with new tools and measurements always being considered and tested. The noninvasive assessment of myocardial work via the pressure-strain relationship is one of the newer tools proposed to evaluate ventricular systolic function. However, prior to using any new tool, one should understand its properties, utility, and limitations. In this commentary we focus on the noninvasive assessment of myocardial work via the pressure-strain relationship from a pediatric point of view. We address the current knowledge, limitations, and propose future directions to better understand this tool.

A single institution anesthetic experience with catheterization of pediatric pulmonary hypertension patients.

Cardiac catheterization remains the gold standard for the diagnosis and management of pediatric pulmonary hypertension (PH). There is lack of consensus regarding optimal anesthetic and airway regimen. This retrospective study describes the anesthetic/airway experience of our single center cohort of pediatric PH patients undergoing catheterization, in which obtaining hemodynamic data during spontaneous breathing is preferential. A total of 448 catheterizations were performed in 232 patients. Of the 379 cases that began with a natural airway, 274 (72%) completed the procedure without an invasive airway, 90 (24%) received a planned invasive airway, and 15 (4%) required an unplanned invasive airway. Median age was 3.4 years (interquartile range [IQR] 0.7-9.7); the majority were either Nice Classification Group 1 (48%) or Group 3 (42%). Vasoactive medications and cardiopulmonary resuscitation were required in 14 (3.7%) and eight (2.1%) cases, respectively; there was one death. Characteristics associated with use of an invasive airway included age <1 year, Group 3, congenital heart disease, trisomy 21, prematurity, bronchopulmonary dysplasia, WHO functional class III/IV, no PH therapy at time of case, preoperative respiratory support, and having had an intervention (p < 0.05). A composite predictor of age <1 year, Group 3, prematurity, and any preoperative respiratory support was significantly associated with unplanned airway escalation (26.7% vs. 6.9%, odds ratio: 4.9, confidence interval: 1.4-17.0). This approach appears safe, with serious adverse event rates similar to previous reports despite the predominant use of natural airways. However, research is needed to further investigate the optimal anesthetic regimen and respiratory support for pediatric PH patients undergoing cardiac catheterization.

Prostaglandin-E1 infusion in persistent pulmonary hypertension of the newborn.

BACKGROUND: Neonates with persistent pulmonary hypertension of the newborn (PPHN) can present with hypoxia and right ventricular dysfunction with resultant inadequate oxygen delivery and end-organ damage. This study describes the use of prostaglandin-E1 (PGE) for ductal patency to preserve right ventricular systolic function and limit afterload in newborns with PPHN. METHODS: This is a retrospective cohort study that follows the hemodynamics, markers of end-organ perfusion, length of therapeutics, and echocardiographic variables of 57 newborns who used prostglandin-E1 in the setting of PPHN. RESULTS: Tachycardia, lactic acidosis, and supplemental oxygen use improved following PGE initiation. Fractional area change (FAC), to assess right ventricular systolic function, and pulmonary arterial acceleration time indexed to right ventricular ejection time (PAAT/RVET), to assess right ventricular afterload, also improved over three time points relative to PGE use (before, during, and after). CONCLUSIONS: Overall, we described the safety and utility of PGE in newborns with severe PPHN for stabilization while allowing natural disease progression.

Safety and tolerability of continuous inhaled iloprost in critically ill pediatric pulmonary hypertension patients: A retrospective case series.

Inhaled iloprost (iILO) has shown efficacy in treating patients with hypoxic lung disease and pulmonary hypertension, inducing selective pulmonary vasodilation and improvement in oxygenation. However, its short elimination half-life of 20-30 min necessitates frequent intermittent dosing (6-9 times per day). Thus, the administration of iILO via continuous nebulization represents an appealing method of drug delivery in the hospital setting. The objectives are: (1) describe our continuous iILO delivery methodology and safety profile in mechanically ventilated pediatric pulmonary hypertension patients; and (2) characterize the initial response of iILO in these pediatric patients currently receiving iNO. Continuous iILO was delivered and well tolerated (median 6 days; range 1-94) via tracheostomy or endotracheal tube using the Aerogen® mesh nebulizer system coupled with a Medfusion® 400 syringe pump. No adverse events or delivery malfunctions were reported. Initiation of iILO resulted in an increase in oxygen saturation from 81.4 ± 8.6 to 90.8 ± 4.1%, p < 0.05. Interestingly, prior iNO therapy for >1 day resulted in a higher response rate to iILO (as defined as a ≥ 4% increase in saturations) compared to those receiving iNO <1 day (85% vs. 50%, p = 0.06). When the use of iILO is considered, continuous delivery represents a safe, less laborious alternative and concurrent treatment with iNO should not be considered a contraindication. However, given the retrospective design and small sample size, this study does not allow the evaluation of the efficacy of continuous iILO on outcomes beyond the initial response. Thus, a prospective study designed to evaluate the efficacy of continuous iILO is necessary.

Associated radiation exposure from medical imaging and excess lifetime risk of developing cancer in pediatric patients with pulmonary hypertension.

Pediatric patients with pulmonary hypertension (PH) receive imaging studies that use ionizing radiation (radiation) such as computed tomography (CT) and cardiac catheterization to guide clinical care. Radiation exposure is associated with increased cancer risk. It is unknown how much radiation pediatric PH patients receive. The objective of this study is to quantify radiation received from imaging and compute associated lifetime cancer risks for pediatric patients with PH. Electronic health records between 2012 and 2022 were reviewed and radiation dose data were extracted. Organ doses were estimated using Monte Carlo modeling. Cancer risks for each patient were calculated from accumulated exposures using National Cancer Institute tools. Two hundred and forty-nine patients with PH comprised the study cohort; 97% of patients had pulmonary arterial hypertension, PH due to left heart disease, or PH due to chronic lung disease. Mean age at the time of the first imaging study was 2.5 years (standard deviation [SD] = 4.9 years). Patients underwent a mean of 12 studies per patient per year, SD = 32. Most (90%) exams were done in children <5 years of age. Radiation from CT and cardiac catheterization accounted for 88% of the total radiation dose received. Cumulative mean effective dose was 19 mSv per patient (SD = 30). Radiation dose exposure resulted in a mean increased estimated lifetime cancer risk of 7.6% (90% uncertainty interval 3.0%-14.2%) in females and 2.8% (1.2%-5.3%) in males. Careful consideration for the need of radiation-based imaging studies is warranted, especially in the youngest of children.

Patent ductus arteriosus and the risk of bronchopulmonary dysplasia-associated pulmonary hypertension.

BACKGROUND: The aim of the study was to determine whether prolonged exposure to a moderate/large patent ductus arteriosus left-to-right shunt (PDA) increases the risk of late (beyond 36 weeks) pulmonary hypertension (BPD-PH) and pulmonary vascular disease (BPD-PVD) during the neonatal hospitalization in preterm infants (<28 weeks' gestation) with bronchopulmonary dysplasia (BPD). METHODS: All infants requiring respiratory support ≥36 weeks had systematic echocardiographic evaluations for BPD-PH at planned intervals. Infants were classified as having either flow-associated BPD-PH (BPD-flow-PH) or BPD-PVD. RESULTS: 256 infants survived ≥36 weeks: 105 had NO BPD (were off respiratory support by 36 weeks); 151 had BPD. 22/151 had BPD-PH (12/22 had BPD-flow-PH from a PDA that persisted beyond 36 weeks; 10/22 had BPD-PVD). Moderate/large PDA shunts that persisted beyond 36 weeks were significantly associated with an increased incidence of BPD-PH due to BPD-flow-PH. We found no association between the duration of PDA exposure and the incidence of BPD-PVD. CONCLUSIONS: Moderate/large PDA shunts increase the risk of flow-associated BPD-PH when present beyond 36 weeks. Although term infants with PDA-congenital heart disease can develop pulmonary vascular remodeling and PVD after months of PDA exposure, we found no echocardiographic evidence in preterm infants that prolonged PDA exposure increases the incidence of BPD-PVD during the neonatal hospitalization. IMPACT: In our study, preterm infants (<28 weeks' gestation) with bronchopulmonary dysplasia (BPD) had a 15% incidence of pulmonary hypertension (PH) beyond 36 weeks' postmenstrual age as a comorbidity. Moderate/large patent ductus arteriosus (PDA) shunts increased the risk of flow-associated PH when present beyond 36 weeks. Although months of prolonged PDA exposure can cause pulmonary vascular remodeling and pulmonary vascular disease (PVD) in term infants with PDA-congenital heart disease, we found no echocardiographic evidence for an association between the duration of PDA exposure and the incidence of late PVD during the neonatal hospitalization in preterm infants with BPD.

A Case of Neonatal Lupus Presenting with Myocardial Dysfunction in the Absence of Congenital Heart Block (CHB): Clinical Management and Brief Literature Review of Neonatal Cardiac Lupus.

Neonatal lupus (NLE) is a rare acquired autoimmune disorder caused by transplacental passage of maternal autoantibodies to Sjogren's Syndrome A or B (SSA-SSB) autoantigens (Vanoni et al. in Clin Rev Allerg Immunol 53:469-476, 2017) which target fetal and neonatal tissues for immune destruction. The cardiac trademark of NLE is autoimmune heart block, which accounts for more than 80% of cases of complete atrioventricular heart block (AVB) in newborns with a structurally normal heart (Martin in Cardiol Young 24: 41-46, 2014). NLE presenting with cardiac alterations not involving rhythm disturbances are described in the literature, but they are rare. Here, we report a case of a neonate with high anti-SSA antibodies who developed severe ventricular dysfunction in the absence of rhythm abnormalities, endocardial fibroelastosis, and dilated cardiomyopathy (Trucco et al. in J Am Coll Cardiol 57:715-723, https://doi.org/10.1016/j.jacc.2010.09.044 , 2011), the most common cardiac presentations of NLE. The patient developed severe multiorgan dysfunction syndrome that required prolonged critical care support but fully recovered and was discharged home. We highlight the unusual clinical features of this NLE case and the importance of timely treatment of NLE allowing complete recovery of a critically ill neonate.

Hemodynamic assessment of transitioning from parenteral prostacyclin to selexipag in pediatric pulmonary hypertension.

Despite the increase in therapeutic options, parenteral prostacyclins remain the cornerstone in the medical management of pulmonary arterial hypertension (PAH). While the use of parenteral prostacyclins in pediatric patients is well documented, less is known about alternative drug delivery methods such as enteral administration. Given that parenteral routes of prostacyclin administration (IV or SC) are invariably accompanied by complicated logistics and lifestyle compromises, enteral prostacyclin administration represents an attractive treatment option. Selexipag (Uptravi®) was approved for adults PAH in 2015. There is limited data on the hemodynamic efficacy of transitioning from parenteral prostacyclins to selexipag, particularly in the pediatric population. We report 11 pediatric PAH patients who underwent this transition, in which 10 had complete cardiac catheterization data before and following the transition to selexipag. All patients/families reported an improvement in quality of life, and the transitions occurred without adverse effects. However, 3 of the 11 (27%) did not tolerate the transition; two for worsening hemodynamics, and one for acute right ventricular failure in the setting of an intercurrent illness. In addition, the transition to selexipag was associated with a modest increase in pulmonary vascular resistance index (6/10) and decrease in cardiac index (6/10) in some patients. Selexipag use in pediatric PAH represents a significant addition to our therapeutic arsenal, and its use provides a meaningful improvement in quality of life compared with other prostacyclin formulations. However, when goals of care include aggressive disease management, a decision between improved quality of life and possible adverse outcomes must be considered, and its substitution should include cautious, close, long-term follow-up.

Persistence of persistent pulmonary hypertension of the newborn: A case of de novo TBX4 variant.

We present a case of a late preterm infant placed on extracorporeal life support in the first day of life for persistent pulmonary hypertension of the newborn. Developmental arrest, pulmonary vascular hypertensive changes, and pulmonary interstitial glycogenosis were present on lung biopsy at 7 weeks of age. Pulmonary hypertension has persisted through childhood. Genetic testing at 8 years identified a novel mutation in TBX4.

A Measurement-Based Protocol Improves Interrater Agreement and Accuracy of Right Ventricular Systolic Pressure Assessment by Echocardiography in Children: A Call for Quality Improvement.

BACKGROUND: Echocardiographic measurements carry the promise of improving interrater (IR) agreement over subjective assessment. The aim of this study was to assess the effect of implementing a measurement-based protocol on IR agreement and accuracy in reporting of right ventricular (RV) systolic pressure in children. The effect of this reporting protocol on IR agreement in reporting RV dilation, hypertrophy, and systolic function was also evaluated. METHODS: Five echocardiography readers reported their assessment of RV systolic pressure, dilation, hypertrophy, and systolic function on 40 deidentified echocardiograms using their individual accustomed methods and then using an agreed-upon protocol based solely on RV measurements. IR agreement was assessed using κ statistics. Accuracy of RV systolic pressure ratings was assessed using the McNemar test in comparison with hemodynamic data obtained by cardiac catheterization. The reliability of the RV measurements was assessed using intraclass correlation coefficient (ICC) and coefficient of variation. RESULTS: IR agreement and accuracy of RV systolic pressure assessment improved after using the measurement-based protocol (agreement from 0.39 [95% CI, 0.27-0.5] to 0.62 [95% CI, 0.48-0.76] and accuracy from 18 of 40 to 29 of 40 [P = .03]). IR agreement of RV dilation improved (from 0.36 [95% CI, 0.25-0.48] to 0.63 [95% CI, 0.48-0.79]), while IR agreement of RV hypertrophy (from 0.29 [95% CI, 0.17-0.42] to 0.35 [95% CI, 0.15-0.55]) and RV systolic function (from 0.57 [95% CI, 0.45-0.69] to 0.53 [95% CI, 0.41-0.66]) did not improve. The reliability of the measurements was good (ICC > 0.8), except for RV free wall thickness (ICC = 0.62, coefficient of variation = 24%) and RV fractional area change (ICC = 0.47, coefficient of variation = 22%), suggesting a possible reason for the lack of improvement in IR agreement of RV hypertrophy and RV systolic function. Heteroscedasticity was observed in the reliability of RV measurements, with the ICC being significantly lower at larger magnitudes for all RV measurements. CONCLUSIONS: Standardization of reporting protocols using RV measurements in place of subjective assessment improved IR agreement and accuracy of RV systolic pressure assessment. Reliable measurements (RV systolic pressure and dilation) resulted in improvement in IR agreement while unreliable measurements (RV hypertrophy and systolic function) did not. Special attention to measurements' reliability and heteroscedasticity of reliability is required when designing clinical protocols to decrease IR disagreement as a source of error.

Pulmonary artery acceleration time in young children is determined by heart rate and transpulmonary gradient but not by pulmonary blood flow: A simultaneous echocardiography-cardiac catheterization study.

INTRODUCTION: Pulmonary artery acceleration time (PAAT) is considered useful for the non-invasive evaluation of pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR). PAAT is dependent on PAP, PVR, pulmonary artery compliance, stroke volume, and heart rate. Its relative dependency on these determinants may differ between young and older children, raising uncertainty regarding its utility in young children. We aim to identify the primary determinants of the PAAT in children less than 36 months undergoing cardiac catheterization and its utility for the diagnosis of elevated PVR. METHODS: We prospectively studied 42 children undergoing cardiac catheterization and simultaneous echocardiography. We determined the correlations of PAAT to the above-mentioned determinants and evaluated receiver operator characteristic (ROC) curves for diagnosis of PVR indexed to body surface area (PVRi) ≥3 Wu*m2 . RESULTS: Median age was 11.5 (IQR 5.2, 21.2) months. Moderate correlations were found between PAAT and mean PAP (R = -.66, p < .001), PVRi (R = -.54, p = .004), pulmonary artery compliance (R = .65, p < .001), transpulmonary gradient (R = -.67, p < .001), stroke volume (R = .61, p = .002), and heart rate (R = -.63, p < .001). In multivariate regression modeling, only transpulmonary gradient and heart rate were independent determinants of PAAT. PAAT ≤77 msec had acceptable utility for diagnosing PVRi ≥ 3 Wu*m2 (AUC .8 [.64, .95], n = 36), low sensitivity (59%), and excellent specificity (94%). CONCLUSION: Transpulmonary gradient and heart rate, but not pulmonary blood flow, are important determinants of PAAT in children <36 months undergoing cardiac catheterization. PAAT has low sensitivity for diagnosing elevated PVRi, therefore, should not be solely relied upon in screening for elevated PVRi in young children.

Genetics dictating therapeutic decisions in pediatric pulmonary hypertension? A case report suggesting we are getting closer.

Despite therapeutic advances over the past decades, pulmonary arterial hypertension (PAH) and related pulmonary vascular diseases continue to cause significant morbidity and mortality in neonates, infants, and children. Unfortunately, an adequate understanding of underlying biology is lacking. There has been a growing interest in the role that genetic factors influence pulmonary vascular disease, with the hope that genetic information may aid in identifying disease etiologies, guide therapeutic decisions, and ultimately identify novel therapeutic targets. In fact, current data suggest that genetic factors contribute to ~42% of pediatric-onset PH compared to ~12.5% of adult-onset PAH. We report a case in which the knowledge that biallelic ATP13A3 mutations are associated with malignant progression of PAH in young childhood, led us to alter our traditional treatment plan for a 21-month-old PAH patient. In this case, we elected to perform a historically high-risk Potts shunt before expected rapid deterioration. Short-term follow-up is encouraging, and the patient remains the only known surviving pediatric PAH patient with an associated biallelic ATP13A3 mutation in the literature. We speculate that an increased use of comprehensive genetic testing can aid in identifying the underlying pathobiology and the expected natural history, and guide treatment plans among PAH patients.

Doppler Echocardiographic Features of Pulmonary Vein Stenosis in Ex-Preterm Children.

BACKGROUND: Echocardiography is used to screen for the presence of pulmonary vein stenosis (PVS) in ex-preterm infants and children. However, there are no standard accepted criteria for screening or diagnosis of PVS by echocardiography. The aim of this study was to identify Doppler waveform features and Doppler systolic and diastolic velocity cutoff values associated with a diagnosis of PVS by cardiac catheterization. METHODS: In this retrospective observational study, the echocardiograms of ex-preterm children <3 years old who underwent cardiac catheterization at a single institution were reviewed. PVS on cardiac catheterization was defined by a mean pressure gradient of >3 mm Hg in the pulmonary vein, with angiographic evidence of stenosis. Pulmonary vein Doppler waveforms, from echocardiograms obtained before catheterization, in children with and without PVS were compared. Nonstenosed veins in patients with PVS were excluded. The systolic and diastolic velocities of blood flow, phasic flow, and return of the Doppler waveform to baseline were analyzed. RESULTS: Forty-seven children were analyzed in the study, 18 children with 25 stenosed pulmonary veins and 29 children with 78 nonstenosed pulmonary veins. Stenosed pulmonary veins had higher peak systolic and diastolic velocities and higher peak and mean pressure gradients as measured by spectral Doppler. Peak systolic and diastolic velocities had areas under the receiver operating characteristic curve of 0.89 (95% CI, 0.79-0.99) and 0.93 (95% CI, 0.85-0.99) for PVS, respectively, and a threshold velocity of 0.7 m/sec had sensitivity of 80% and 84% and specificity of 94%. There was no correlation between Doppler-derived pulmonary vein mean gradient and measured pulmonary vein mean gradient during cardiac catheterization in stenosed pulmonary veins. Presence of phasic flow in the pulmonary vein and return of the Doppler waveform to baseline were associated with a nonstenosed pulmonary vein (sensitivity of 94% and 60% and specificity of 52% and 60%, respectively). CONCLUSIONS: Systolic and diastolic Doppler velocities and features of the waveform can discriminate stenosed pulmonary veins confirmed by cardiac catheterization in ex-preterm children. These results suggest the use of lower systolic and diastolic Doppler velocity cutoff values than currently published to screen for PVS in ex-preterm children. These cutoff values require validation in prospective studies.

Safety and Tolerability of a Rapid Transition From Intravenous Treprostinil to Oral Selexipag in Three Adolescent Patients With Pulmonary Arterial Hypertension.

There is limited published experience with transitioning pediatric patients from parenteral treprostinil to oral selexipag therapy. In addition, published transitions have typically been protracted, taking several weeks to complete. We present a case series of 3 adolescent patients who were transitioned from parenteral treprostinil to oral selexipag over a 5- to 7-day period. Their clinical courses leading up to the transitions are summarized and their outcomes are described. The 3 patients were successfully rapidly transitioned during an inpatient hospitalization without any observed adverse events or prostacyclin-related side effects. We conclude that when indicated rapid transition of parenteral to oral prostacyclin therapy may be performed safely in adolescents in an inpatient setting.

Practice patterns of pulmonary hypertension secondary to left heart disease among pediatric pulmonary hypertension providers.

Development of pulmonary hypertension (PH) in patients with left side heart disease (LHD) is a predictor of poor prognosis. The use of pulmonary vasodilators in PH associated with LHD (PH-LHD) is controversial. In this study, we describe the practice patterns regarding the use of pulmonary vasodilators in PH-LHD among a group of international pediatric PH specialists. A survey was distributed to the members of three pediatric PH networks: PPHNet, PVRI, and REHIPED. The survey queried participants on the rationale, indications, and contraindications of the use of pulmonary vasodilators in children with PH-LHD. Forty-seven PH specialists from 39 PH centers completed the survey. Participants included PH specialists from North America (57%), South America (15%), and Europe (19%). The majority of participants (74%) recommended the use of pulmonary vasodilators only in patients with combined pre-capillary and post-capillary pulmonary hypertension. Participants required the presence of clinical symptoms or signs of heart failure (68%) or right ventricular dysfunction by echocardiography (51%) in order to recommend pulmonary vasodilator therapy. There was no agreement regarding hemodynamic criteria used to recommend pulmonary vasodilators or the etiologies of LHD considered contraindications for using pulmonary vasodilators to manage PH-LHD. Of the available PH-targeted drugs, most participants preferred the use of phosphodiesterase-5-inhibitors for this indication. In conclusion, the practice of recommending pulmonary vasodilators in PH-LHD is highly variable among international pediatric PH specialists. Most specialists of those surveyed (57% in North America) would consider the use of pulmonary vasodilators in PH-LHD only if pre-capillary pulmonary hypertension and right ventricular dysfunction are present.

Longitudinal B-Type Natriuretic Peptide Levels Predict Outcome in Infants with Congenital Diaphragmatic Hernia.

OBJECTIVE: To evaluate B-type natriuretic peptide (BNP) as a longitudinal biomarker of clinical outcome in infants with congenital diaphragmatic hernia (CDH). STUDY DESIGN: We conducted a retrospective study of 49 infants with CDH, classifying the cohort by respiratory status at 56 days, based on a proposed definition of bronchopulmonary dysplasia for infants ≥32 weeks' gestation: good outcome (alive with no respiratory support) and poor outcome (ongoing respiratory support or death). BNP levels were available at age 1-5 weeks. Longitudinal BNP trends were assessed using mixed-effects modeling. Receiver operating characteristic curves were generated to identify BNP cutoffs maximizing correct outcome classification at each time point. The time to reach BNP cutoff by outcome was assessed using Kaplan-Meier curves for weeks 3-5. RESULTS: Twenty-nine infants (59%) had a poor outcome. Infants with a poor outcome were more likely than those with a good outcome to have liver herniated into the thorax (90% vs 50%; P = .002) and to undergo nonprimary repair (93% vs 35%; P < .001). Mixed-effects modeling demonstrated a differing decline in BNP over time by outcome group (P = .003 for interaction). BNP accurately predicted outcome at 3-5 weeks (area under the curve, 0.81-0.82). BNP cutoffs that maximized correct outcome classification decreased over time from 285 pg/mL at 3 weeks to 100 pg/mL at 4 weeks and 48 pg/mL at 5 weeks. Time to reach the cutoffs of 100 pg/mL and 48 pg/mL were longer in the poor outcome group (log-rank P = .006 and <.0001, respectively). CONCLUSIONS: Elevated BNP accurately predicts poor outcome in infants with CDH at age 3-5 weeks, with declining cutoffs over 3-5 weeks of age.

Clinical Utility of Echocardiography in Former Preterm Infants with Bronchopulmonary Dysplasia.

BACKGROUND: The clinical utility of echocardiography for the diagnosis of pulmonary vascular disease (PVD) in former preterm infants with bronchopulmonary dysplasia (BPD) is not established. Elevated pulmonary vascular resistance (PVR) rather than pulmonary artery pressure (PAP) is the hallmark of PVD. We evaluated the utility of echocardiography in infants with BPD in diagnosing pulmonary hypertension and PVD (PVR >3 Wood units × m2) assessed by cardiac catheterization. METHODS: A retrospective single center study of 29 infants born ≤29 weeks of gestational age with BPD who underwent cardiac catheterization and echocardiography was performed. PVD was considered present by echocardiography if the tricuspid valve regurgitation jet peak velocity was >2.9 m/sec, post-tricuspid valve shunt systolic flow velocity estimated a right ventricular systolic pressure >35 mm Hg, or systolic septal flattening was present. The utility (accuracy, sensitivity, and positive predictive value [PPV]) of echocardiography in the diagnosis of PVD was tested. Subgroup analysis in patients without post-tricuspid valve shunts was performed. Echocardiographic estimations of right ventricular pressure, dimensions, function, and pulmonary flow measurements were evaluated for correlation with PVR. RESULTS: The duration between echocardiography and cardiac catheterization was a median of 1 day (interquartile range, 1-4 days). Accuracy, sensitivity, and PPV of echocardiography in diagnosing PVD were 72%, 90.5%, and 76%, respectively. Accuracy, sensitivity, and PPV increased to 93%, 91.7%, and 100%, respectively, when infants with post-tricuspid valve shunts were excluded. Echocardiography had poor accuracy in estimating the degree of PAP elevation by cardiac catheterization. In infants without post-tricuspid valve shunts, there was moderate to good correlation between indexed PVR and right ventricular myocardial performance index (rho = 0.89, P = .005), systolic to diastolic time index (0.84, P < .001), right to left ventricular diameter ratio at end systole (0.66, P = .003), and pulmonary artery acceleration time (0.48, P = .05). CONCLUSIONS: Echocardiography performs well in screening for PVD in infants with BPD and may be diagnostic in the absence of a post-tricuspid valve shunt. However, cardiac catheterization is needed to assess the degree of PAP elevation and PVR. The diagnostic utility of echocardiographic measurements that correlate with PVR should be evaluated prospectively in this patient population.