Prevalence of pulmonary hypertension in obstructive sleep apnea and its relation to disease severity

STUDY OBJECTIVES

The purpose of this study is to examine the prevalence of pulmonary hypertension (PHTN) in children with obstructive sleep apnea (OSA) using echocardiographic (ECHO) parameters and to examine ECHO findings as they relate to severity of OSA.

METHODS

A retrospective cohort study of patients with OSA undergoing polysomnogram and ECHO within 30 days of each other, between January 1, 2015, and December 31, 2020, was performed, excluding cardiac disease. ECHO evidence of PHTN was defined as ≥ 2 of the following: tricuspid regurgitation velocity > 3.0 m/s, pulmonary acceleration/ejection time ratio < 0.3, left ventricular eccentricity index > 1.5, and right ventricular dysfunction or abnormal geometry. ECHO parameters were compared to OSA severity using obstructive apnea-hypopnea index, percent of time with oxygen saturation < 90%, and percent of time with end-tidal carbon dioxide > 50 mmHg. Odds ratios were calculated for each comorbidity to evaluate for risk factors.

RESULTS

Of 509 patients, 4.3% were found to have echocardiographic evidence of PHTN. Neither obstructive apnea-hypopnea index severity nor worsening hypoxemia or hypercarbia correlated with worsening ECHO parameters. Comorbidities including bronchopulmonary dysplasia (odds ratio, 5.22, 2.01-13.53), prematurity (odds ratio, 3.10, 1.28-7.47), and autism (odds ratio, 3.69, 1.01-13.49) were associated with increased odds of PHTN.

CONCLUSIONS

Significant echocardiographic evidence of PHTN was seen in 4.3% of children with OSA. ECHO findings of PHTN did not correlate with polysomnogram parameters. Comorbidities, particularly bronchopulmonary dysplasia, prematurity, and autism, appear to be a risk factor for developing PHTN in patients with OSA.

CITATION

Milligan I, Shaw AK, Leu R, Kanaan U, Michelfelder E. Prevalence of pulmonary hypertension in obstructive sleep apnea and its relation to disease severity. J Clin Sleep Med. 2024;20(5):675-680.

Prenatal Diagnosis of Congenital Heart Disease: The Crucial Role of Perinatal and Delivery Planning

Although most congenital heart defects (CHDs) are asymptomatic at birth, certain CHD lesions are at significant risk of severe hemodynamic instability and death if emergent cardiac interventions are not performed in a timely fashion. Therefore, accurate identification of at-risk fetuses and appropriate delivery resource planning according to the degree of anticipated hemodynamic instability is crucial. Fetal echocardiography has increased prenatal CHD detection in recent years due to advancements in ultrasound techniques and improved obstetrical cardiac screening protocols, enabling the prediction of newborns' hemodynamic status. This assessment can guide multidisciplinary resource planning for postnatal care, including selection of delivery site, delivery room management, and transport to a cardiac center based on CHD risk severity. This review will discuss fetal cardiovascular physiology and the circulatory changes that occur at the time of and immediately following birth, outline fetal echocardiographic findings used to risk-stratify newborns with CHDs, and outline principles for neonatal resuscitation and initial transitional care in neonates with these complex CHD lesions.

Anatomic and physiologic diagnostic discrepancies in fetuses with single ventricle congenital heart disease in a contemporary cohort

OBJECTIVE

Image quality of fetal echocardiography (FE) has improved in the recent era, but few recent studies have reported the accuracy of FE specifically in single ventricle congenital heart disease (SV). Our study aims to assess the ability of FE to correctly predict postnatal anatomy and physiology in SV in a contemporary cohort.

METHODS

The contemporary, clinical reports of FE with SV performed from 7/2017 to 7/2021 were compared with postnatal echocardiograms in a formal quality assurance program. SV were grouped by anatomic subtype. Diagnostic errors were designated as major if the error would have resulted in significant alteration in fetal counseling or postnatal management. Remaining errors were classified as minor. Physiologic discrepancies, including prostaglandin dependency (PGE-D), atrioventricular valve regurgitation (AVVR), pulmonary venous obstruction, and atrial septal restriction were assessed by review of postnatal course.

RESULTS

A total of 119 subjects were analyzed. SV subtypes in the cohort included hypoplastic left heart syndrome (HLHS) (n=68), tricuspid atresia (n=16), double inlet left ventricle (n=12), unbalanced atrioventricular canal (UAVC) (n=11), heterotaxy (n=9), and other (n=3). The rate of major anatomic and physiologic errors was low (n=6, 5.0%). A higher proportion of minor errors were noted in HLHS and tricuspid atresia but the differences were not statistically significant. Physiologic discrepancies were uncommon, with three major discrepancies including underestimation of degree of venous obstruction in one non-HLHS fetus with total anomalous pulmonary venous return, overestimation of atrial septal restriction in one HLHS fetus, and incorrect prediction of PGE-D with 1 false-negative for pulmonary blood flow. No discrepancy in degree of AVVR or atrial septal restriction affected postnatal care. Minor physiologic discrepancies included two false-positive predictions of PGE-D with 1 false-positive for ductal-dependent systemic flow, and 1 false-positive for pulmonary blood flow.

CONCLUSIONS

In this contemporary review of FE in SV at our center, there was high accuracy in describing anatomic and physiologic findings in fetuses with SV. Major physiologic discrepancies were uncommon but included important cases of false-negative prediction of PGE-dependence and underestimation of obstruction of total anomalous pulmonary venous return. These data can both inform more accurate counseling of families with SV fetuses and guide diagnostic improvement efforts. This article is protected by copyright. All rights reserved.

Contemporary Outcomes in Fetuses Diagnosed with Vascular Rings

Vascular rings are increasingly identified on fetal echocardiography. The purpose of this study is to analyze clinical outcomes and patterns of diagnostic testing in fetuses with vascular rings diagnosed by echocardiography. A retrospective cohort study was performed of fetuses with postnatally confirmed vascular rings from 2017 to 2022. Clinical outcomes included type and timing of symptoms, and timing of surgical intervention. Freedom from symptoms and/or surgery was assessed by Kaplan-Meier analysis. Frequency of genetic and diagnostic testing (barium esophagogram, CT/MRI angiogram, and bronchoscopy) was also assessed. Overall, 46 patients were evaluated (91% with a right aortic arch/left ductus and 4% with a double aortic arch). A vascular ring was isolated in 59%, associated with structural heart lesions in 33%, and associated with noncardiac anomalies in 8%. Prenatal diagnoses increased over time. Symptoms developed in 24% (11/46); 82% (9/11) had respiratory and 45% (5/11) had gastroesophageal complaints. Surgery was performed in 17% (11/46). Symptoms presented bimodally, prior to 100 or after 400 days of life. There was no difference in the type of symptoms for early (< 100 days) or late (> 400 days) presenters. Symptomatic patients received more diagnostic testing. Genetic testing was obtained in 46% and positive in 33%, with 22q11 deletion and Trisomy 21 being identified. Prenatal diagnoses of vascular rings increased over time, with subjects developing symptoms bimodally in early or late infancy. The frequency of genetic testing was suboptimal given the prevalence of genetic abnormalities seen in this population.

Congenitally Corrected Transposition of the Great Arteries: Fetal Diagnosis, Associations, and Postnatal Outcome: A Fetal Heart Society Research Collaborative Study

Background Fetal diagnosis of congenitally corrected transposition of the great arteries (ccTGA) has been increasingly reported; however, predictors of clinical outcomes remain underexplored. We undertook a multicenter, retrospective study to investigate natural history, associated anomalies, and outcomes of fetal ccTGA. Methods and Results Fetuses with ccTGA diagnosed from January 2004 to July 2020 within 20 North American programs were included. Fetuses with severe ventricular hypoplasia thought to definitively preclude biventricular repair were excluded. We included 205 fetuses diagnosed with ccTGA at a median gestational age of 23 (interquartile range, 21-27) weeks. Genetic abnormalities were found in 5.9% tested, with extracardiac anomalies in 6.3%. Associated cardiac defects were diagnosed in 161 (78.5%), with atrioventricular block in 23 (11.3%). On serial fetal echocardiogram, 39% demonstrated a functional or anatomic change, most commonly increased tricuspid regurgitation (6.7%) or pulmonary outflow obstruction (11.1%). Of 194 fetuses with follow-up, 26 were terminated, 3 experienced fetal death (2 with atrioventricular block), and 165 were live-born. Of 158 with postnatal data (median follow-up 3.7 years), 10 (6.6%) had death/transplant before 1 year. On univariable analysis, fetal factors associated with fetal death or death/transplant by 1 year included ≥ mild tricuspid regurgitation, pulmonary atresia, aortic obstruction, fetal arrhythmia, and worsening hemodynamics on serial fetal echocardiogram (defined as worse right ventricular function, tricuspid regurgitation, or effusion). Conclusions Associated cardiac lesions and arrhythmias are common in fetal ccTGA, and functional changes commonly occur through gestation. Worse outcomes are associated with fetal tricuspid regurgitation (≥mild), any arrhythmia, pulmonary atresia, aortic obstruction, and worsening hemodynamics on serial echocardiograms. These findings can inform prenatal counseling and perinatal management planning.

Fetal Diagnosis in a Unique Case of Vascular and Cardiac Interdependence in Omphaloischiopagus Conjoined Twins

•

Cardiac interdependence in conjoined twins is a rare phenomenon.

•

Presence of congenital heart disease may be an important prognostic factor.

•

There is high risk of high-output heart failure and pulmonary hypertension in the donor twin.

•

If reconstruction is feasible, early separation may improve the chance of survival.

Intrauterine fetal demise after prenatal diagnosis of congenital heart disease: assessment of risk

OBJECTIVES

Elective deliveries in fetal congenital heart disease (CHD) attempt to balance fetal and neonatal risk with the goal of optimizing overall outcome. However, the magnitude of the risk for intrauterine fetal demise (IUFD) is unclear. This study aimed to (1) determine the rate of IUFD and (2) identify fetal risk factors associated with IUFD.

METHODS

Retrospective review of pregnancies complicated by CHD between 1998 and 2010. Data were collected regarding pregnancy outcome, extracardiac anomalies (ECA), genetic and cardiac diagnoses, severity of valve regurgitation, gestational age at birth and birth weight. Fisher's exact test and odds ratios were used to compare outcomes between groups.

RESULTS

A total of 501 pregnancies analyzed resulted in 445 live births, 22 IUFD, 16 terminations and 18 unknown outcomes. Amongst IUFD, 27% had a genetic diagnosis, 50% had an ECA and 27% had severe valve regurgitation. IUFD odds increased threefold with ECA and sevenfold with severe valve regurgitation. IUFD occurred in 1.2% without risk factors.

CONCLUSIONS

IUFD in fetuses with CHD is associated with ECA, genetic syndromes and severe valve regurgitation. In absence of these fetal characteristics, the occurrence of IUFD is low, although it remains higher than in fetuses without CHD.

Abstract 18132: Prenatal Evaluation of the Fetal Cardiovascular Profile Score in a Multicenter Study of Ebstein Anomaly/Tricuspid Valve Dysplasia

Introduction: The cardiovascular profile (CVP) score is an echo based multivariable approach for assessment of fetal hemodynamics. The CVP score has been shown to be useful in predicting the outcome of fetuses with heart failure, growth restriction, and select congenital heart defects. The score ranges from 0 to 10, with points deducted for abnormal hemodynamics. In a previous pilot study of 21 fetuses with EA/TVD, a CVP score <7 was associated with poor outcomes. The aim of this study was to investigate the prognostic significance of the CVP score in a larger cohort of fetuses with EA/TVD.

Methods: This 23-center study was a retrospective review of fetal echo data and outcomes in a cohort of 243 fetuses diagnosed with EA/TVD from 2005-2011. Both the first and last fetal echo in gestation were evaluated. Hydrops, heart size, cardiac function, and umbilical arterial and venous Dopplers were scored. The primary outcome was perinatal death, defined as fetal demise or death prior to neonatal discharge. Categorical variables were compared using Chi-squared tests; p-values <0.05 were considered statistically significant.

Results: Complete data on the first and last fetal echocardiograms to calculate a CVP score were available in 144 fetuses at the time of the first fetal echo (median GA 26.07 wks, range 14-40) and 73 fetuses at the time of the last fetal echo (median GA: 25 wks, range 18 -34). The median CVP scores for the first and last fetal echo were 8 (range 4-9) and 7 (range 7-9) among survivors vs. 7 (range 0-10) and 6 (range 1-8) among non-survivors. Fetuses with EA/TVD that died were more likely to have a CVP score <7 compared to those that survived: 33.3% vs. 11.6 %, (p=0.004) on the first fetal echo and 60.0% vs. 28.6 % (p=0.015) on the last fetal echo. However, no statistically significant difference in survival was observed for fetuses whose CVP score decreased from the first to the last echo. (p=0.95).

Conclusions: In this study, fetuses with EA/TVD with CVP scores <7 on the first or last fetal echo were less likely to survive. The CVP score may be a valuable tool to identify fetuses with EA/TVD at risk of poor outcome for whom novel therapeutic approaches might be warranted.

Outcomes of congenital diaphragmatic hernia in the modern era of management

OBJECTIVE

To identify clinical factors associated with pulmonary hypertension (PH) and mortality in patients with congenital diaphragmatic hernia (CDH).

STUDY DESIGN

A prospective cohort of neonates with a diaphragm defect identified at 1 of 7 collaborating medical centers was studied. Echocardiograms were performed at 1 month and 3 months of age and analyzed at a central core by 2 cardiologists independently. Degree of PH and survival were tested for association with clinical variables using Fischer exact test, χ(2), and regression analysis.

RESULTS

Two hundred twenty patients met inclusion criteria. Worse PH measured at 1 month of life was associated with higher mortality. Other factors associated with mortality were need for extracorporeal membrane oxygenation, patients inborn at the treating center, and patients with a prenatal diagnosis of CDH. Interestingly, patients with right sided CDH did not have worse outcomes.

CONCLUSIONS

Severity of PH is associated with mortality in CDH. Other factors associated with mortality were birth weight, gestational age at birth, inborn status, and need for extracorporeal membrane oxygenation.

Estimated cardiac output and cardiovascular profile score in fetuses with high cardiac output lesions

OBJECTIVE

High cardiac output lesions are associated with an increased risk of fetal death, largely as a result of cardiac failure and hydrops fetalis. The cardiovascular profile score (CVPS) has been used to characterize cardiovascular wellbeing, and has been linked to fetal outcomes in other conditions. We aimed to test the hypothesis that elevated combined cardiac output (CCO) in fetuses with high output lesions may be associated with worsening cardiovascular status, as evidenced by a lower CVPS.

METHODS

A retrospective review was performed of fetuses with high cardiac output lesions that underwent echocardiography between July 2006 and November 2010. Diagnoses included sacrococcygeal teratoma, placental chorioangioma and vein of Galen aneurysm. Fetal echocardiographic evaluation included assessment of CVPS, as well as Doppler/two-dimensional estimation of CCO, indexed to estimated fetal weight (CCOi). The relationship between CCO and CVPS was assessed.

RESULTS

A total of 35 fetuses were studied: 27 had sacrococcygeal teratoma, seven had chorioangioma and one had vein of Galen aneurysm. There was a significant inverse relationship between mean logCCOi and CVPS (r2  = 0.48, P = 0.008). Of 31 patients with clinical outcome data, 10 experienced either in-utero demise or intervention; 80% of these fetuses had a CVPS of < 8.

CONCLUSIONS

There is an inverse relationship between CCO and CVPS in the fetus with high cardiac output lesions. As a measure of fetal cardiovascular wellbeing in this population, the CVPS may be a useful tool for stratifying risk and for selection for intervention in these fetuses.

A fetus with hypoplastic left heart syndrome and tricuspid stenosis with evolving hydrops fetalis

Hypoplastic left heart syndrome (HLHS) is a severe congenital heart defect that results in death if not treated shortly after birth. In approximately 60 to 70% of cases, HLHS can be detected prenatally and generally is well tolerated due to the presence of the foramen ovale and ductus arteriosus, which allow for blood to bypass the left side of the heart but still provide adequate blood flow to the systemic circulation. A rare case of HLHS involving a fetus with tricuspid valve stenosis, abnormal venous Doppler findings, and hydrops is reported.

Prevalence and progression of recipient-twin cardiomyopathy in early-stage twin-twin transfusion syndrome

OBJECTIVE

The management of twin-twin transfusion syndrome (TTTS) in its early stages (Quintero Stages I and II) is controversial. We describe the prevalence, severity, incidence and rate of progression of recipient-twin cardiomyopathy in Stages I and II TTTS.

METHODS

Among 451 cases of TTTS evaluated between 2004 and 2009, 123 (27.3%) cases of Stages I and II were reviewed. Echocardiography was used to 'upstage' cases based on the presence or absence of mild (IIIA), moderate (IIIB), or severe (IIIC) recipient cardiomyopathy. Progression was defined by worsening in the degree of recipient-twin cardiomyopathy from initial presentation or failure to respond to amnioreduction. Outcome data included progression of recipient-twin cardiomyopathy, treatment and survival to birth. Data were compared by the chi-square, Fisher's exact test or t-test as appropriate.

RESULTS

Seventy-seven of 123 (62.6%) cases were Quintero Stage I and 46/123 (37.4%) Quintero Stage II. Eighty (65.0%) were upstaged to Cincinnati Stage IIIA (n = 25), IIIB (n = 23) or IIIC (n = 32). Management included observation in 11 (8.9%), amnioreduction in 26 (21.1%), amnioreduction followed by selective fetoscopic laser photocoagulation (SFLP) in 43 (35.0%) and primary SFLP in 43 (35.0%). Of 80 cases managed by observation or amnioreduction initially, 43 (53.8%) progressed within a mean duration of 1.4 ± 1.5 weeks. The incidence of progression increased significantly as degree of recipient-twin cardiomyopathy at presentation worsened: Stage I, 9/27 (33.3%); Stage II, 8/15 (53.3%); Stage IIIA, 8/16 (50.0%); Stage IIIB, 10/10 (100%); and Stage IIIC, 8/12 (66.7%) (χ(2) = 14, P < 0.01). Overall fetal survival was 205 out of 244 (84.0%). Fetal survival with observation only was 81.8% (18/22), with amnioreduction only it was 92.3% (48/52), with initial observation or amnioreduction followed by SFLP it was 86.9% (73/84) and with primary SFLP it was 76.7% (66/86).

CONCLUSION

Echocardiography demonstrates a high incidence of recipient-twin cardiomyopathy in early-stage TTTS. The more advanced the recipient-twin cardiomyopathy is, the more likely is progression to occur during observation or following amnioreduction.

The relationship between amniotic fluid levels of brain-type natriuretic peptide and recipient cardiomyopathy in twin-twin transfusion syndrome

OBJECTIVE

We sought to evaluate amniotic fluid brain natriuretic peptide (BNP) levels as a biomarker of recipient twin (RT) cardiomyopathy (RTCM) in twin-twin transfusion syndrome.

STUDY DESIGN

Amniotic fluid samples were obtained from 157 twin-twin transfusion syndrome RTs and from 6 singletons (controls) from 2007 through 2009. N-terminal prohormone BNP (NT-proBNP) levels were quantified by enzyme-linked immunosorbent assay. RTCM was classified as mild (IIIA), moderate (IIIB), or severe (IIIC) by fetal echocardiography. The relationship between NT-proBNP and RTCM was evaluated using analysis of variance. The ability of NT-proBNP to predict moderate or greater RTCM was evaluated by receiver operating characteristic analysis.

RESULTS

There is a significant positive correlation between NT-proBNP levels and worsening RTCM (r = 0.33; P < .001). NT-proBNP thresholds of 569 fmol/mg and 369 fmol/mg had a sensitivity of 70% and 87%, and specificity of 67% and 42%, respectively, in predicting moderate or greater RTCM.

CONCLUSION

This is the first large case series that demonstrates a relationship between NT-proBNP and RTCM. This pathophysiologic insight supports ongoing efforts to develop screening biomarkers.

Improved recipient survival with maternal nifedipine in twin-twin transfusion syndrome complicated by TTTS cardiomyopathy undergoing selective fetoscopic laser photocoagulation

OBJECTIVE

The purpose of this study was to evaluate the effect of maternal nifedipine on fetal survival when started 24-48 hours before selective fetoscopic laser photocoagulation (SFLP).

STUDY DESIGN

We conducted a case control study of consecutive cases of twin-twin transfusion syndrome (TTTS) in which TTTS cardiomyopathy was treated with maternal nifedipine 24-48 hours before SFLP, compared with gestational age and stage-matched control cases. The primary outcome was recipient and donor survival.

RESULTS

One hundred forty-one cases of TTTS were treated with nifedipine, and 152 gestational age- and stage-matched control cases were analyzed. There was a significant increase in overall fetal survival in nifedipine-treated cases compared with control cases (237/284 [83%] vs 232/308 [75%]; P = .015). There is an increase in survival of recipients who were treated with nifedipine in stage IIIA (100% vs 81%; P = .021) and IIIB (93% vs 71%; P = .014); however, there was no difference in donor survival.

CONCLUSION

Maternal nifedipine is associated with improved recipient survival in TTTS that undergoes SFLP. This is the first study to suggest a benefit of adjunctive maternal medical therapy in patients with TTTS who undergo SFLP.

Acute effects of selective fetoscopic laser photocoagulation on recipient cardiac function in twin-twin transfusion syndrome

OBJECTIVE

This study evaluated the acute effects of selective fetoscopic laser photocoagulation (SFLP) on recipient cardiovascular function in a twin-twin transfusion syndrome (TTTS) pregnancy.

STUDY DESIGN

This was a retrospective chart review of echocardiographic data in TTTS including right (RV) and left (LV) ventricular Doppler myocardial performance index (MPI); LV and RV end diastolic wall thickness; and umbilical artery (UA), vein (UV), and ductus venosus (DV) Dopplers. The primary outcome measures were improved MPI defined as greater than 10% interval decrease in left and/or right MPI. Data were analyzed by Student t test and Fisher's exact test.

RESULTS

Sixty-five patients met inclusion criteria. SFLP results in a significant improvement in UV and DV Doppler and an increase in both RV and LV wall thickness. A 10% or greater improvement in recipient LV MPI after SFLP is associated with improved recipient survival as compared with unimproved LV MPI (100% vs 86.1%, P = .05).

CONCLUSION

Improved recipient myocardial performance index after SFLP is associated with improvement in recipient survival.

Early manifestations and spectrum of recipient twin cardiomyopathy in twin-twin transfusion syndrome: relation to Quintero stage

OBJECTIVES

To examine cardiac structural and functional changes in twin-twin transfusion syndrome (TTTS), relative to Quintero stage, as a means of evaluating the spectrum of cardiomyopathy in TTTS.

METHODS

This was a cross-sectional, retrospective study of 42 consecutive cases of TTTS referred to a single fetal therapy center. Quintero stages were assigned by standard criteria. Presence of ventricular hypertrophy, cardiomegaly, atrioventricular valve regurgitation (AVVR), ventricular systolic dysfunction and right ventricular outflow tract obstruction on fetal echocardiography were noted. The Doppler myocardial performance index (MPI), an index of global ventricular function, was calculated for both ventricles in subjects with adequate Doppler data. We compared cardiac changes across Quintero stages.

RESULTS

There was no cardiomyopathy observed in donor twins. The majority of subjects presented at Quintero Stage I (n = 14), II (n = 14) or III (n = 11), with fewer at Stages IV (n = 2) or V (n = 1). As early as Quintero Stages I and II, a significant proportion of recipient twins had ventricular hypertrophy (17/28, 61%), AVVR (6/28, 21%) or quantitative abnormalities in either right (12/24, 50%) or left (14/24, 58%) ventricular function. Increasing prevalence of biventricular systolic dysfunction and cardiomegaly accompanied advancing Quintero stage.

CONCLUSIONS

Changes in cardiac structure and function not reflected in Quintero staging occur in recipient twins early in the evolution of TTTS. Incorporation of cardiac findings into assessment of TTTS severity may prove useful in stratification of risk and treatment selection.

Revisiting animal models of aortic stenosis in the early gestation fetus

BACKGROUND

Mechanisms leading to left ventricular hypoplasia and endocardial fibroelastosis in the fetus remain unknown. Prevailing theory is that obstruction to blood flow through the left ventricle leads to elevated end-diastolic pressures, compromised myocardial perfusion, and endocardial ischemia. Fetal interventions are now being performed, based on the presumption that they would prevent such pathogenic mechanisms.

METHODS

Forty first-trimester fetal sheep (mean gestational age, 53 days) were studied. Severe fetal left ventricular outflow obstruction was created by banding the ascending aorta in 25 fetuses; 15 control fetuses underwent "sham" surgery with thoracotomy. Serial fetal echocardiography was used to assess left ventricular growth and fetal hemodynamics. Findings were correlated to morphologic and histopathologic changes, and intracardiac pressure measurements obtained from fetal cardiac catheterization.

RESULTS

Surviving banded fetuses (n = 13) had one of two phenotypes: compensatory left ventricular hypertrophy (n = 7) or noncompensatory left ventricular dilatation (n = 6) with hydrops and severe left ventricular dysfunction. All fetuses had elevated left ventricular end-diastolic pressures (mean, 21 mm Hg; range, 14 to 28 mm Hg), which correlated to the gradient across the ascending aorta (mean, 41 mm Hg; range, 28 to 73 mm Hg). In vivo echocardiography findings were incongruous with those at autopsy, and demonstrated preservation of left ventricular growth indices in all fetuses. Endocardial fibroelastosis and myocardial fibrosis were not observed in any banded fetus.

CONCLUSIONS

While early gestational obstruction to flow can compromise left ventricular function in the fetus, it does not retard normal growth. Similarly, an elevated left ventricular end-diastolic pressure is not sufficient to cause myocardial fibrosis or endocardial fibroelastosis in the fetus.

Significance of reverse orientation of the ductus arteriosus in neonates with pulmonary outflow tract obstruction for early intervention

Reverse orientation of the ductus arteriosus (RDA), defined as an inferior angle at the aortic junction of <90 degrees , is associated with pulmonary atresia; however, the significance of RDA in nonatretic pulmonary outflow tract obstruction (POTO) is unknown. The purpose of this study was to evaluate the relation between ductal morphology and the need for early intervention. Ductal morphology was retrospectively reviewed in 76 neonatal cases of POTO. Patients were stratified to those with conotruncal (CT) or primary pulmonary valve (PV) abnormalities. The prevalence of RDA was 40 of 68 (59%) and was higher in patients with CT defects (28 of 30, 93%) compared with PV abnormalities (12 of 38, 32%; chi-square = 26.4, p <0.0001). Early intervention was required in 29 of 40 patients with RDA (73%) compared with only 8 of 28 patients with normal ductal morphology (31%; chi-square = 12.8, p <0.001). The proportion of patients with RDA who required early intervention was greater in PV abnormalities (12 of 12, 100%) compared with CT defects (17 of 28, 61%; chi-square = 6.5, p <0.02). Importantly, after excluding patients with pulmonary atresia, these analyses were unchanged. In patients with nonatretic POTO, a threshold inferior angle of 65 degrees was predictive of the need for early intervention. RDA in patients with PV abnormalities, or CT defects and an inferior angle <65 degrees , is a specific indicator for early intervention. These findings demonstrate an association between RDA in the context of atretic and nonatretic POTO and the need for early intervention. The need for early intervention should be considered when RDA is identified in this population.

Predictive value of fetal pulmonary venous flow patterns in identifying the need for atrial septoplasty in the newborn with hypoplastic left ventricle

BACKGROUND

Pulmonary venous Doppler (PVD) flow patterns in the fetus with hypoplastic left heart syndrome (HLHS) have been correlated with restrictive interatrial communication or intact atrial septum (RAS) postnatally; however, the ability of PVD to identify the neonate requiring emergent atrial septoplasty (EAS) for severe left atrial hypertension and hypoxemia has not been critically evaluated. It was the purpose of this study to determine the predictive power of fetal PVD in identifying the need for EAS in newborns with HLHS and RAS.

METHODS AND RESULTS

Forty-one patients with fetal PVD flow analysis and postnatally confirmed HLHS were studied. Pulsed-wave assessment of PVD flow included S-, D-, and A-wave velocity, time-velocity integral (VTI) of forward and reverse flow, and S/D velocity and forward/reverse VTI ratio. Neonatal EAS was used as the primary clinical outcome variable. Receiver operating characteristic curves were used to determine cutpoints at which PVD indices best predicted EAS. Cutpoints were evaluated for clinical accuracy and usefulness by use of Bayesian analysis. Eight of 41 subjects underwent EAS. Need for EAS was most accurately predicted by forward/reverse VTI ratio <5 (sensitivity, 0.88, 95% CI, 0.49 to 0.99; specificity, 0.97, 95% CI, 0.82 to 0.99), which, when present, increases the posttest likelihood of EAS to 74%, assuming a pretest prevalence of 10%. Accuracy and usefulness of other PVD indices were affected by false-positive results.

CONCLUSIONS

In the fetus with HLHS, a PVD forward/reverse VTI ratio of <5 is the strongest predictor of the need for EAS in the newborn period. These observations should improve our ability to identify and expectantly manage the fetus with HLHS and RAS.