Impact of antenatal screening on the presentation of infants with congenital heart disease to a cardiology unit

Fifteen-minute consultation: How to spot serious heart disease in the newborn

Congenital heart disease (CHD) is common and important as it remains a leading cause of neonatal morbidity and appreciable mortality. Prenatal diagnosis, the presence of a murmur, cyanosis, tachypnoea and/or poor or differential peripheral pulses raise the suspicion of CHD aided by differential pre/postductal saturations. Yet even serious CHD may not be considered when such clues are absent. Nevertheless, there are clinical cues which may alert the clinician to the possibility of a significant CHD which may lead to an early and accurate diagnosis and appropriate intervention to achieve best results. This paper addresses these issues which become especially difficult if caring for infants away from facilities provided by tertiary centres. Tachypnoea on the first postnatal day is generally non-cardiac in origin. Exceptions include large arteriovenous fistulae and/or 'pump' (ventricular) failure. In addition, attention is drawn to two important confounding factors in the newborn, namely the patency of the ductus arteriosus and the initially high pulmonary vascular resistance, both of which alter and may mask the clinical findings of a serious cardiac abnormality. An appreciation of the physiological changes that occur in early infancy will aid the clinician's understanding of CHD as it affects the newborn.

Early detection of significant congenital heart disease: The contribution of fetal cardiac ultrasound and newborn pulse oximetry screening

Fetal cardiac and newborn pulse oximetry screening has greatly facilitated the detection of cardiac abnormalities, which may be serious with potentially dire neonatal consequences. The prenatal diagnosis of a serious cardiac abnormality allows the attending obstetrician to organise the much safer in-utero transfer of the fetus for delivery at a tertiary centre, particularly if there is evidence of a duct-dependent lesion that may require the infusion of Prostaglandin E1 to maintain duct patency pending surgical intervention. Newborn pulse oximetry alerts the paediatrician that the baby may have a significant cardiac abnormality, which warrants further elucidation prior to discharge, rather than for the baby to represent unwell a few days later. Despite these advances, serious cardiac abnormalities may be missed on screening. Their detection then falls back onto the clinical acumen of the attending paediatrician/family physician to review the history, carefully elicit and evaluate the clinical signs further aided by whatever investigations that may be available at the birthing hospital, frequently less resourced than the tertiary centres. At the outset, a brief synopsis is provided of the clinical findings that may point to a cardiac abnormality. That is followed by a critical review of the accuracy of prenatal and newborn pulse oximetry screening with emphasis on the lesions that may be missed. Suggestions are made as to how to improve the diagnostic accuracy.

Evaluation of Circulating Cardiovascular Biomarker Levels for Early Detection of Congenital Heart Disease in Newborns in Sweden

IMPORTANCE

Congenital heart disease (CHD) is the most common congenital malformation in humans worldwide. Circulating cardiovascular biomarkers could potentially improve the early detection of CHD, even in asymptomatic newborns.

OBJECTIVES

To assess the performance of a dried blood spot (DBS) test to measure the cardiovascular biomarker amino terminal fragment of the prohormone brain-type natriuretic peptide (NT-proBNP) levels in newborns and to compare DBS with standard EDTA analysis in control newborns during the first week of life.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study was conducted in a single regional pediatric service in southern Sweden. Healthy, term neonates born between July 1, 2018, and May 31, 2019, were prospectively enrolled and compared against retrospectively identified newborns with CHD born between September 1, 2003, and September 30, 2019. Neonates who required inpatient treatment beyond the standard postnatal care were excluded.

EXPOSURE

New DBS test for NT-proBNP quantification in newborns that used 3 μL of blood vs the current screening standard.

MAIN OUTCOMES AND MEASURES

Performance of the new test and when combined with pulse oximetry screening was measured by receiver operating characteristic curve analysis. Performance of the new test and EDTA screening was compared using Pearson linear correlation analysis.

RESULTS

The DBS samples of 115 neonates (81 control newborns and 34 newborns with CHD, of whom 63 were boys [55%] and the mean [SD] gestational age was 39.6 [1.4] weeks) were analyzed. The new NT-proBNP test alone identified 71% (n = 24 of 34) of all CHD cases and 68% (n = 13 of 19) of critical CHD cases as soon as 2 days after birth. Detection of any CHD type improved to 82% (n = 28 of 34 newborns) and detection of critical CHD improved to 89% (n = 17 of 19 newborns) when combined pulse oximetry screening and NT-proBNP test results were used. Performance of the NT-proBNP test was excellent when control newborns were matched to newborns with CHD born between July 1, 2018, and May 31, 2019 (area under the curve, 0.96; SE, 0.027; 95% CI, 0.908-1.0; asymptotic P < .05).

CONCLUSIONS AND RELEVANCE

This study found that NT-proBNP assay using minimal DBS samples appears to be timely and accurate in detecting CHD in newborns and to discriminate well between healthy newborns and newborns with various types of CHD. This finding warrants further studies in larger cohorts and highlights the potential of NT-proBNP to improve neonatal CHD screening.

Prenatal diagnosis and prevalence of critical congenital heart defects: an international retrospective cohort study

OBJECTIVES

To assess international trends and patterns of prenatal diagnosis of critical congenital heart defects (CCHDs) and their relation to total and live birth CCHD prevalence and mortality.

SETTING

Fifteen birth defect surveillance programmes that participate in the International Clearinghouse for Birth Defects Surveillance and Research from 12 countries in Europe, North and South America and Asia.

PARTICIPANTS

Live births, stillbirths and elective terminations of pregnancy for fetal anomaly diagnosed with 1 of 12 selected CCHD, ascertained by the 15 programmes for delivery years 2000 to 2014.

RESULTS

18 243 CCHD cases were reported among 8 847 081 births. The median total prevalence was 19.1 per 10 000 births but varied threefold between programmes from 10.1 to 31.0 per 10 000. CCHD were prenatally detected for at least 50% of the cases in one-third of the programmes. However, prenatal detection varied from 13% in Slovak Republic to 87% in some areas in France. Prenatal detection was consistently high for hypoplastic left heart syndrome (64% overall) and was lowest for total anomalous pulmonary venous return (28% overall). Surveillance programmes in countries that do not legally permit terminations of pregnancy tended to have higher live birth prevalence of CCHD. Most programmes showed an increasing trend in prenatally diagnosed CCHD cases.

DISCUSSION AND CONCLUSIONS

Prenatal detection already accounts for 50% or more of CCHD detected in many programmes and is increasing. Local policies and access likely account for the wide variability of reported occurrence and prenatal diagnosis. Detection rates are high especially for CCHD that are more easily diagnosed on a standard obstetric four-chamber ultrasound or for fetuses that have extracardiac anomalies. These ongoing trends in prenatal diagnosis, potentially in combination with newborn pulse oximetry, are likely to modify the epidemiology and clinical outcomes of CCHD in the near future.

The Critically Ill Infant with Congenital Heart Disease

This article presents an approach for identification of infants with congenital heart disorders. These disorders are difficult to diagnose because of the complexity and variety of cardiac malformations; additionally presentation can be complicated by age-dependent physiology. By compiling data from the history and the physical examination, the emergency physician can identify lesion category and initiate stabilization procedures. Critical congenital cardiac lesions can be classified as left-sided obstructive ductal dependent, right-sided obstructive ductal dependent, and shunting or mixing. The simplified approach categorizes infants with these lesions respectively as "pink," "blue," or "gray." The emergency provider can provide life-saving stabilization until specialized care can be obtained.

Transport of infants with congenital heart disease: benefits of antenatal diagnosis

Infants with significant congenital heart disease (CHD) typically require transport from their birth centre to a regional paediatric cardiac centre. Antenatal diagnosis of CHD allows early pre-emptive stabilisation, and is associated with improved early clinical status. However, the effect of antenatal diagnosis on the transport characteristics of infants with CHD has not been previously investigated. The aim of this study was to compare the transport characteristics of infants with antenatal and postnatal diagnosis of CHD. This study is a retrospective cohort study of all infants of ≤10 days and ≥34 weeks of gestation with CHD admitted to the Royal Children's Hospital, Melbourne (RCH) over 5 years. Demographic, diagnosis, and transport data were recorded. Cases of complex CHD were included in this study. Of 320 infants with complex CHD, 198 (62 %) had antenatal diagnosis (ANdx) and 122 (38 %) had postnatal diagnosis (PNdx). There was no significant difference in sex, birth weight, or gestation between ANdx and PNdx groups. Average age of referral was 15 vs. 53.4 h in ANdx vs. PNdx groups. Aggregate transfer distance in the ANdx group was 2216 km and in the PNdx group was 10,274 km (P < 0.0001). Of the infants, 39 % in the PNdx group required highest-acuity "time critical" transports compared to 6 % of ANdx infants (P = 0.0001). Conversely, only 11 % of the infants in the PNdx group had lowest acuity "non-urgent" transfers, compared to 24 % of ANdx infants (P = 0.003). PNdx was associated with significantly higher rates of invasive ventilation (36 vs 20 %; P = 0.01) and higher rates of inotrope use (19 vs. 9 %; P = 0.007) during transport.

CONCLUSIONS

Improved antenatal detection would allow for safer, less resource intense transfers of infants with CHD.

Improving diagnostic accuracy in the transport of infants with suspected duct-dependent congenital heart disease

AIM

To identify factors that distinguish duct-dependent congenital heart disease (DDCHD) from non-DDCHD in newborn infants.

METHOD

A retrospective, cohort study. The Newborn Emergency Transport Service, Victoria (NETS) is a retrieval service for all inter-hospital neonatal transfers, and the Royal Children's Hospital, Melbourne (RCH) is a paediatric cardiac referral centre for the state of Victoria, Australia. All infants ≤10 days and ≥34 weeks gestation with suspected CHD and/or persistent pulmonary hypertension of the newborn (PPHN), transferred by NETS from non-tertiary neonatal units to RCH, over a 4-year period.

RESULTS

Of 142 eligible infants, 81 had DDCHD and 61 had non-DDCHD, of whom 51 had PPHN. Diagnostic accuracy of DDCHD by the NETS team was 77%. Presence of a heart murmur, abnormal pulses, upper and lower limb blood pressure (BP) difference >10 mmHg, cardiomegaly, initial SpO2 of <92%, PaO2 <50 mmHg, and pre-post ductal SpO2 difference >10% were significantly associated with DDHCD on univariate analysis. No single clinical finding was significantly associated with DDCHD on multivariate analysis. Labile SpO2 , abnormal lung parenchyma, mean BP <40 mmHg, pH <7.25, lactate >5 and FiO2 >0.5 were significantly associated with non-DDCHD, but at multivariate analysis only labile SpO2 and mean BP <40 mmHg were associated with non-DDCHD.

CONCLUSIONS

Clinical diagnosis of DDCHD outside of a cardiac centre is challenging. No single factor predicts DDCHD. Combined interpretation of clinical, physiological and x-ray findings may assist.

Rightward convexity of the great vessel arising from the anterior ventricle: a novel fetal marker for transposition of the great arteries

OBJECTIVES

Traditionally transposition of the great arteries (TGA) is suggested by bifurcation of the great vessel arising from the posterior ventricle and the parallel course of the great vessels as they leave the heart. These findings may be difficult to demonstrate, requiring additional fetal echocardiographic features to indicate TGA. In this study, we investigated a new marker of TGA, namely rightward convexity of the great vessel arising from the anterior ventricle.

METHODS

We reviewed fetal studies from 2006 to 2010 in which an antenatal diagnosis of TGA was confirmed postnatally. We specifically viewed images obtained by scanning the great vessel arising from the anterior ventricle cranially to the superior mediastinum at the level of the three vessels and trachea view and compared them with similar views in normal hearts.

RESULTS

In 21 cases of confirmed TGA, the great vessel arising from the anterior ventricle (aorta) coursing cranially demonstrated an abnormal convexity to the right. This was in contrast to convexity to the left or lack of convexity of the great vessel (pulmonary artery) arising from the anterior ventricle in fetuses with a normal heart. In two fetuses rightward vessel convexity from the anterior ventricle was the clue on the initial scan suggesting TGA, which was subsequently confirmed. In addition, only two vessels, the superior vena cava and aorta, were demonstrated in fetuses with TGA, the pulmonary artery and ductus arteriosus lying below (caudal to) the transverse arch.

CONCLUSIONS

Noting the rightward convexity of the great vessel arising from the anterior ventricle may aid in the prenatal diagnosis of TGA. Furthermore, the relative simplicity of this sign may make it valuable in fetal screening for this cardiac defect.

Transporting newborns with transposition of the great arteries

AIMS

The aim of the study was to examine the prevalence and management of outborn babies with a post-natally confirmed diagnosis of transposition of the great arteries (TGA) requiring transport by the Newborn and Paediatric Emergency Transport Service (NETS), New South Wales during the epoch 1991-2010.

METHOD

A retrospective audit of NETS database and case notes. The physiological status, interventions and any complications encountered from the point of referral to NETS (pre-transport), stabilisation (transport) and subsequent admission to the receiving hospital (post-transport) were evaluated.

RESULTS

One hundred fifty-seven infants with TGA were transported, with an average of eight per year (1:11,598 births). Seven (4%) had an antenatal diagnosis, and 72 (46%) had a post-natal diagnosis prior to referral. Physiological and clinical parameters demonstrated overall clinical stability; however, 47% of the babies had a PaO(2) <30 mmHg, and approximately one-fifth had oxygen saturations <70%. Rates of mechanical ventilation and prostaglandin E(1) administration were approximately 50%. A quarter of transported babies encountered a transport-related event, including one death and two babies for which a decision was reached to forego life-sustaining treatment at the referring hospital.

CONCLUSIONS

Most newborns with TGA remain stable or improve during transport. There is a rate of adverse events; however, this reinforces the need to facilitate delivery where there is ready access to interventional paediatric cardiology services.

Routine use of color Doppler in fetal heart scanning in a low-risk population

Objectives. To investigate the detection rate of major fetal heart defects in a low-risk population implementing routine use of color Doppler. Material and Methods. In a prospective observational study, all women undergoing fetal heart scanning (including 6781 routine examinations in the second trimester) during a three-year period were included. First a gray-scale scanning was performed including assessment of the four-chamber view and the great vessels. Thereafter three cross-sectional planes through the fetal thorax were assessed with color Doppler. Results. Thirty-nine fetuses had major heart defects, and 26 (67%) were prenatally detected. In 9/26 (35%) of cases the main ultrasound finding was related to the use of color Doppler. The survival rate of live born children was 91%. Conclusions. Routine use of color Doppler in fetal heart scanning in a low-risk population may be helpful in the detection of major heart defects; however, still severe malformations were missed prenatally.

Fetal cardiac screening and variation in prenatal detection rates of congenital heart disease: why bother with screening at all?

Antenatal screening for fetal cardiac abnormalities was introduced over 25 years ago, yet detection of congenital heart disease before birth remains a challenge. While experienced tertiary centers report a high level of diagnostic accuracy, with most major forms of congenital heart disease being detectable before birth, the overall detection rate remains low. Pregnancies at increased risk of having an affected baby are referred to tertiary centers for fetal ECG, but most cases of congenital heart disease will occur in low-risk pregnancies. These cases will only be detected by screening the low-risk population at the time of routine obstetric scanning. Many obstetric ultrasound units have learnt to successfully obtain, and correctly interpret, views of the heart, including the four-chamber view and outflow tract views. However, standards for doing this are not uniform, nationally or internationally, so there is a significant variation in detection rates across individual countries and between different countries. Early diagnosis of babies with lesions that can result in cardiovascular collapse and death, could improve their survival as well as reducing morbidity. In addition, detection of a cardiac abnormality during pregnancy allows time to prepare parents for the likely course of events after birth. It also facilitates detection of other abnormalities in the baby and gives parents a choice, even if the choice is difficult and unwelcome. As well as providing parents with accurate and up-to-date information regarding the their baby’s abnormality, it is vital to provide continuing support to help them deal with the problem, regardless of what decisions they make. Much work remains to establish a uniform standard for antenatal detection of cardiac abnormalities. More recent national guidelines for examining the fetal heart along with formalized auditing processes should help to achieve this, although considerable time and effort will be required, particularly with regard to the teaching and training required.

Síndrome de deleção 22q11.2 e cardiopatias congênitas

OBJETIVO: Revisar as características clínicas, etiológicas e diagnósticas da síndrome de deleção 22q11 e sua associação com as cardiopatias congênitas. FONTES DOS DADOS: Foram pesquisados artigos científicos presentes nos portais Medline, Lilacs e SciELO, utilizando-se descritores específicos como "22q11", "DiGeorge syndrome", "velocardiofacial syndrome", "congenital heart defects" e "cardio-vascular malformations". O período adotado para a revisão foi de 1980 a 2009. SÍNTESE DOS DADOS: As malformações cardíacas são os defeitos congênitos observados mais frequentemente ao nascimento e representam um problema importante de Saúde Pública. Dentre suas principais causas conhecidas destaca-se a síndrome de deleção 22q11, também chamada de síndrome de DiGeorge, síndrome velocardiofacial e CATCH22. Trata-se de uma doença autossômica domi-nante caracterizada por um fenótipo altamente variável, o que dificulta em muito seu reconhecimento clínico. Além disso, a maior parte dos pacientes apresenta uma microdeleção identificada principalmente por técnicas de citogenética molecular, como a hibridização in situ fluorescente, pouco disponíveis em nosso meio. De forma similar a outras síndromes, a síndrome de deleção 22q11 associa-se a certos defeitos cardíacos específicos, no caso os do tipo conotruncal. Apesar disso, não há ainda na literatura um consenso sobre quais os pacientes com car-diopatia congênita que deveriam ser investigados para a síndrome de deleção 22q11. CONCLUSÕES: Cardiologistas e cirurgiões cardíacos, espe-cialmente pediátricos, devem estar cientes das peculiaridades e dos cuidados dispensados à síndrome de deleção 22q11. Os indivíduos com a síndrome apresentam comumente alterações envolvendo vários sistemas, o que pode levar a dificuldades e a complicações durante seu manejo clínico e cirúrgico.

Simple targeted arterial rendering (STAR) technique: a novel and simple method to visualize the fetal cardiac outflow tracts

OBJECTIVE

To describe a novel and simple technique—simple targeted arterial rendering (STAR)—to visualize the fetal cardiac outflow tracts from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView).

METHODS

We developed a technique to image the outflow tracts by drawing three dissecting lines through the four-chamber view of the heart contained in a STIC volume dataset. Each line generated the following plane: (a) Line 1: ventricular septum en face with both great vessels (pulmonary artery anterior to the aorta); (b) Line 2: pulmonary artery with continuation into the longitudinal view of the ductal arch; and (c) Line 3: long-axis view of the aorta arising from the left ventricle. The pattern formed by all three lines intersecting approximately through the crux of the heart resembles a star. The technique was then tested in 50 normal fetal hearts at 15.3–40.4 weeks' gestation. To determine whether the technique could identify planes that departed from the normal images, we tested the technique in four cases with proven congenital heart defects (ventricular septal defect (VSD), transposition of great vessels, tetralogy of Fallot and pulmonary atresia with intact ventricular septum).

RESULTS

The STAR technique was able to generate the intended planes in all 50 normal cases. In the abnormal cases, the STAR technique allowed identification of the VSD, demonstrated great vessel anomalies and displayed views that deviated from what was expected from the examination of normal hearts.

CONCLUSIONS

This novel and simple technique can be used to visualize the outflow tracts and ventricular septum en face in normal fetal hearts. Inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease involving the great vessels and/or the ventricular septum. The STAR technique may simplify examination of the fetal heart and could reduce operator dependency.

Ethical issues in fetal management: a cardiac perspective

The ethical issues behind the management of a fetus with a serious abnormality and the decisions made in relation to the outcome of the pregnancy are complex. This reflective paper deals with the ethical principles of managing a pregnancy with a congenital anomaly, with particular emphasis on the fetus with a serious cardiac abnormality. One major ethical concern is whether the fetus is or is not independent being to whom obligations of beneficence are owed. We review the debate on this matter, and suggest that it is ethically more appropriate for physicians who are involved in management of fetal abnormality not to adopt and insist on their own position on this matter. Rather, the appropriate course is to respect the pregnant woman's own view of her fetus and how it should be regarded. This is an application of the principle of respect for autonomy. Within this framework, we discuss the difficulties in counselling a pregnant woman or expectant couple in this situation, and recommend three key steps in ethically sound counselling.

Prenatal screening for major congenital heart disease: superiority of outflow tracts over the 4-chamber view

OBJECTIVE

The purpose of this study was to determine the relative importance of the 4-chamber view (4CV) compared with the outflow tract views (OFTVs) in prenatal screening for major congenital heart disease (CHD).

METHODS

We prospectively evaluated 200 consecutive infants undergoing cardiac surgery at our institution for major CHD. By reviewing the infants' medical records and conducting bedside interviews with their parents or guardians, we evaluated detection rates both prenatally and postnatally (before and after discharge to home), and we noted any prenatally identifiable risk factors for CHD. For each infant, we determined whether the 4CV or OFTVs would be expected to have been normal or abnormal on routine midgestation screening fetal sonography.

RESULTS

A prenatal diagnosis of CHD was made in 65 infants (33%): 30 of 124 low-risk pregnancies (24%) and 35 of 76 high-risk pregnancies (46%). An abnormal screening midgestation 4CV would have been expected in up to 63% of the infants, whereas abnormal midgestation OFTVs would have been expected in up to 91% of the infants. Thus, the potential sensitivity for detecting major CHD was higher with the OFTVs than with the 4CV (91% versus 63%; P < .001). Moreover, the OFTVs were more sensitive than the 4CV for detecting ductal-dependent forms of CHD. Diagnosis after discharge to home occurred in 39 of 135 postnatal diagnoses (29%), including many cases of isolated outflow tract abnormalities requiring early invasive intervention.

CONCLUSIONS

Cases of major neonatal CHD with OFTV abnormalities predominate over cases with 4CV abnormalities, particularly among those forms of CHD requiring early invasive intervention.

The hidden mortality of transposition of the great arteries and survival advantage provided by prenatal diagnosis

OBJECTIVE

To describe the sensitivity of fetal anomaly scanning at detecting transposition of the great arteries (TGA) and to investigate whether prenatal detection improves survival.

DESIGN

Retrospective review of survival by comparing those who had an antenatal diagnosis with those who did not.

SETTING

Population-based study in Wessex region over 13 years.

POPULATION

Babies with isolated TGA and an intact ventricular septum.

METHODS

Review of outcomes by comparing those who had an antenatal diagnosis with those who did not.

MAIN OUTCOME MEASURES

Mortality rates in each group.

RESULTS

TGA occurred more commonly in boys than in girls. Using the existing national screening policy, the antenatal detection rate of TGA was only 6.9% over the study period, improving to 25% in the last 4 years. This contrasts with a 40% detection rate when TGA was associated with a ventricular septal defect (VSD). All the babies who had TGA diagnosed antenatally survived through surgery. Of those who were not diagnosed antenatally, two were stillborn, five died before the diagnosis was made and four died after surgery. Although the difference in survival rates between those who were antenatally diagnosed and those who were not is not statistically significant (chi(2)= 3.9; P = 0.11), some of these deaths could have been prevented if a prenatal diagnosis had been made.

CONCLUSIONS

Improved antenatal diagnosis could lead to a significant reduction in the mortality associated with TGA. The current low detection rate of TGA in the UK could be improved by the inclusion of outflow tract views in routine fetal anomaly scans, and we believe that the extra workload is justified.