Risk of major congenital heart disease in pregestational maternal diabetes is modified by hemoglobin A1c

OBJECTIVES

The association between pregestational diabetes mellitus (PDM) and risk of congenital heart disease (CHD) is well recognized; however, the importance of glycemic control and other coexisting risk factors during pregnancy is less clear. We sought to determine the relative risk (RR) of major CHD (mCHD) among offspring from pregnancies complicated by PDM and the effect of first-trimester glycemic control on mCHD risk.

METHODS

We determined the incidence of mCHD (requiring surgery within 1 year of birth or resulting in pregnancy termination or fetal demise) among registered births in Alberta, Canada. Linkage of diabetes status, maximum hemoglobin A1c (HbA1c) at < 16 weeks' gestation and other covariates was performed using data from the Alberta Perinatal Health Program registry. Risk of mCHD according to HbA1c was estimated as an adjusted RR (aRR), calculated using log-binomial modeling.

RESULTS

Of 1412 cases of mCHD in 594 773 (2.37/1000) births in the study period, mCHD was present in 48/7497 with PDM (6.4/1000; RR, 2.8 (95% CI, 2.1-3.7); P < 0.0001). In the entire cohort, increased maternal age (aRR, 1.03 (95% CI, 1.02-1.04); P < 0.0001) and multiple gestation (aRR, 1.37 (95% CI, 1.1-1.8); P = 0.02) were also associated with mCHD risk, whereas maternal prepregnancy weight > 91 kg was not. The stratified risk for mCHD associated with HbA1c ≤ 6.1%, > 6.1-8.0% and > 8.0% was 4.2/1000, 6.8/1000 and 17.1/1000 PDM/gestational diabetes mellitus births, respectively; the aRR of mCHD associated with PDM and HbA1c > 8.0% was 8.5 (95% CI, 5.0-14.4) compared to those without diabetes and 5.5 (95% CI, 1.6-19.4) compared to PDM with normal HbA1c (≤ 6.1%).

CONCLUSIONS

PDM is associated with a RR of 2.8 for mCHD, increasing to 8.5 in those with HbA1c > 8%. These data should facilitate refinement of referral indications for high-risk pregnancy screening. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Treatment, not delivery, of the late preterm and term fetus with supraventricular arrhythmia

OBJECTIVE

While in-utero treatment of sustained fetal supraventricular arrhythmia (SVA) is standard practice in the previable and preterm fetus, data are limited on best practice for late preterm (34 + 0 to 36 + 6 weeks), early term (37 + 0 to 38 + 6 weeks) and term (> 39 weeks) fetuses with SVA. We reviewed the delivery and postnatal outcomes of fetuses at ≥ 35 weeks of gestation undergoing treatment rather than immediate delivery.

METHODS

This was a retrospective case series of fetuses presenting at ≥ 35 weeks of gestation with sustained SVA and treated transplacentally at six institutions between 2012 and 2022. Data were collected on gestational age at presentation and delivery, SVA diagnosis (short ventriculoatrial (VA) tachycardia, long VA tachycardia or atrial flutter), type of antiarrhythmic medication used, interval between treatment and conversion to sinus rhythm and postnatal SVA recurrence.

RESULTS

Overall, 37 fetuses presented at a median gestational age of 35.7 (range, 35.0-39.7) weeks with short VA tachycardia (n = 20), long VA tachycardia (n = 7) or atrial flutter (n = 10). Four (11%) fetuses were hydropic. In-utero treatment led to restoration of sinus rhythm in 35 (95%) fetuses at a median of 2 (range, 1-17) days; this included three of the four fetuses with hydrops. Antiarrhythmic medications included flecainide (n = 11), digoxin (n = 7), sotalol (n = 11) and dual therapy (n = 8). Neonates were liveborn at 36-41 weeks via spontaneous vaginal delivery (23/37 (62%)) or Cesarean delivery (14/37 (38%)). Cesarean delivery was indicated for fetal SVA in two fetuses, atrial ectopy or sinus bradycardia in three fetuses and obstetric reasons in nine fetuses that were in sinus rhythm at the time of delivery. Twenty-one (57%) cases were treated for recurrent SVA after birth.

CONCLUSION

In-utero treatment of the near term and term (≥ 35-week) SVA fetus is highly successful even in the presence of hydrops, with the majority of cases delivered vaginally closer to term, thereby avoiding unnecessary Cesarean section. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Impact of rural residence and low socioeconomic status on rate and timing of prenatal detection of major congenital heart disease in a jurisdiction of universal health coverage

OBJECTIVE

Socioeconomic status (SES) and distance of residence from tertiary care may impact fetal detection of congenital heart disease (CHD), partly through reduced access to and quality of obstetric ultrasound screening. It is unknown whether SES and remoteness of residence (RoR) affect prenatal detection of CHD in jurisdictions with universal health coverage. We examined the impact of SES and RoR on the rate and timing of prenatal diagnosis of major CHD within the province of Alberta in Canada.

METHODS

In this retrospective study, we identified all fetuses and infants diagnosed with major CHD in Alberta, from 2008 to 2018, that underwent cardiac surgical intervention within the first year after birth, died preoperatively, were stillborn or underwent termination. Using maternal residence postal code and geocoding, Chan SES index quintile, geographic distance from a tertiary-care fetal cardiology center and the Canadian Index of Remoteness (IoR) were calculated. Outcome measures included rates of prenatal diagnosis and diagnosis after 22 weeks' gestation. Risk ratios (RR) were calculated using log-binomial regression and stratified by rural (≥ 100 km from tertiary care) or metropolitan (< 100 km from tertiary care) residence, adjusting for year of birth and the obstetric ultrasound screening view in which CHD would most likely be detected (four-chamber view; outflow-tract view; three-vessel or three-vessels-and-trachea or non-standard view; septal view).

RESULTS

Of 1405 fetuses/infants with major CHD, prenatal diagnosis occurred in 814 (57.9%). Residence ≥ 100 km from tertiary care (adjusted RR, 1.19; 95% CI, 1.05-1.34) and higher IoR (adjusted RR, 1.9; 95% CI, 1.1-3.3) were associated with missed prenatal diagnosis of major CHD. Similarly, residence ≥ 100 km from tertiary care (adjusted RR, 1.41; 95% CI, 1.22-1.62) and higher IoR (adjusted RR, 3.6; 95% CI, 2.2-8.2) were associated with prenatal diagnosis after 22 weeks. Although adjusted and unadjusted analyses showed no association between Chan SES index quintile and prenatal-diagnosis rate overall nor for residence in rural areas, in metropolitan regions, lower SES quintiles were associated with missed prenatal diagnosis (quintile 1: RR, 1.24; 95% CI, 1.02-1.50) and higher risk of diagnosis after 22 weeks' gestation (quintile 1: RR, 1.46; 95% CI, 1.10-1.93; quintile 2: RR, 1.66; 95% CI, 1.24-2.23).

CONCLUSIONS

Despite universal healthcare, rural residence in Alberta is associated with lower rate of prenatal diagnosis of major CHD and higher risk of late prenatal diagnosis (≥ 22 weeks). Within metropolitan regions, lower SES impacts negatively prenatal-diagnosis rate and timing. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Clinical presentation, genetic etiology and outcome associated with fetal cardiomyopathy: comparison of two eras

OBJECTIVE

To assess the rate and type of genetic diagnosis and clinical outcome of cases of fetal cardiomyopathy (CM) during two eras, in order to examine the impact of advanced genetic testing and improved perinatal management strategies.

METHODS

All diagnoses of fetal CM in Alberta, Canada, encountered between 2003 and 2019, were reviewed retrospectively. Genetic, cardiac and non-cardiac diagnoses and clinical outcome were documented. Cases with CM secondary to extracardiac pathology and maternal conditions were excluded. Cases diagnosed in the earlier era of the study period (2003-2012) were compared with those diagnosed in the later era (2013-2019).

RESULTS

Thirty-eight cases of fetal CM met the inclusion criteria. Median gestational age (GA) at diagnosis was 22.8 (range, 13.4-37.4) weeks. Associated structural heart disease was present in 39% (15/38) of cases and 24% (9/38) had arrhythmia. Hydrops was identified in 29% (11/38) of cases at presentation, and a further 18% (7/38) developed hydrops later in gestation. Twenty-six percent (10/38) of cases underwent termination of pregnancy and 24% (9/38) had intrauterine death. Of liveborn cases, neonatal death occurred in 16% (3/19), late death occurred in 21% (4/19) and 63% (12/19) were alive at the last follow-up. Excluding cases that had termination of pregnancy and those with a liveborn infant who received planned palliative care, the rate of neonatal survival was higher in the later compared with the earlier era (69% (11/16) vs 45% (5/11)), although the difference was not statistically significant (P = 0.26). A genetic etiology was confirmed in 39% (15/38) of cases and strongly suspected in 24% (9/38). A significantly higher proportion of cases had a confirmed or strongly suspected genetic etiology in the later era compared with in the earlier era (76% (19/25) vs 38% (5/13); P = 0.04).

CONCLUSIONS

In the recent era, a higher proportion of fetal CM cases had a confirmed or strongly suspected genetic etiology than reported previously. Based on comparison with older series, modern perinatal management strategies may not have a significant impact on neonatal survival in cases of fetal CM; however, a larger study would be better powered to detect more subtle differences. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal features of ductus arteriosus-related branch pulmonary stenosis in fetal pulmonary atresia

OBJECTIVE

Ductus arteriosus (DA)-related branch pulmonary stenosis (PS), due to ductal tissue migration into the proximal pulmonary artery (PA) ipsilateral to the DA, is common in newborns with pulmonary atresia (PAtr) and contributes significantly to their mortality and morbidity. We sought to define fetal echocardiographic predictors of DA-PS in PAtr.

METHODS

This was a study of all neonates diagnosed prenatally with PAtr and a DA-dependent pulmonary circulation, with a DA that joined the underbelly of the arch, who had undergone surgical or catheter intervention in our hospital between 2009 and 2018. The postnatal echocardiograms and clinical records were reviewed to confirm the presence or absence of DA-PS based on the need for angioplasty at initial intervention and/or development of proximal PA stenosis post intervention. Fetal echocardiograms were examined for the features of DA-PS.

RESULTS

Of 53 fetuses with PAtr, 34 (64%) had analyzable images, including 20/34 (59%) with and 14/34 (41%) without DA-PS. An inability to visualize the branch PAs in the same plane, largely associated with abnormal DA insertion into the ipsilateral PA (85% of cases), had sensitivity, specificity and positive (PPV) and negative (NPV) predictive values of 75%, 100%, 100% and 74%, respectively, for the prediction of postnatal DA-PS. The mean branch PA posterior bifurcation angle was more obtuse in cases with DA-PS compared to cases without DA-PS (117° ± 17° vs 79° ± 17°, P < 0.001), and an angle of > 100°, the preoperative cut-off observed previously in affected newborns, had a sensitivity, specificity, PPV and NPV of 88%, 79%, 82% and 85%, respectively. The receiver-operating-characteristics curve revealed an angle of ≥ 105° to have a sensitivity and specificity of 88% and 93%, respectively, for prenatal prediction of DA-PS. The presence of one or both features (inability to image in the same plane and the posterior bifurcation angle of ≥ 105°) had a sensitivity, specificity, PPV and NPV of 100%, 93%, 95% and 100%, respectively.

CONCLUSION

An inability to visualize the branch PAs in the same plane, associated with abnormal insertion of the DA in most cases, and/or the presence of a posterior PA bifurcation angle of ≥ 105° are predictive features of postnatal DA-PS in fetuses with PAtr. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Fetal echocardiographic predictors of biventricular circulation in hypoplastic left heart complex

OBJECTIVES

To determine which echocardiographic features of hypoplastic left heart complex (HLHC) in the fetal period are predictive of biventricular (BV) circulation and to evaluate the long-term outcome of patients with HLHC, including rates of mortality, reintervention and development of further cardiac disease.

METHODS

Echocardiograms of fetuses with HLHC obtained at 18-26 weeks and 27-36 weeks' gestation between 2004 and 2017 were included in the analysis. The primary outcome was successful BV circulation (Group 1). Group 2 included patients with single-ventricle palliation, death or transplant. Univariate analysis was performed on data obtained at 18-26 and 27-36 weeks and multivariate logistic regression was performed on data obtained at 27-36 weeks only.

RESULTS

Of the 51 included cases, 44 achieved successful BV circulation (Group 1) and seven did not (Group 2). Right-to-left/bidirectional foramen ovale (FO) flow and a higher mitral valve (MV) annulus Z-score were associated with successful BV circulation on both univariate and multivariate analysis. Bidirectional or left-to-right FO flow, left ventricular length (LVL) Z-score of < -2.4 and a MV Z-score of < -4.5 correctly predicted 80% of Group 2 cases. Late follow-up was available for 41 patients. There were two late deaths in Group 2. Thirteen patients in Group 1 required reintervention, 12 developed mitral stenosis and five developed isolated subaortic stenosis.

CONCLUSIONS

BV circulation is common in fetuses with HLHC. Higher MV annulus and LVL Z-scores and right to left direction of FO flow are important predictors of BV circulation. Long-term sequelae in those with BV circulation may include mitral and subaortic stenosis. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Population trends in prenatal detection of transposition of great arteries: impact of obstetric screening ultrasound guidelines

OBJECTIVES

Dextro-transposition of the great arteries (d-TGA) is one of the most common critical neonatal heart defects, with a low detection rate antenatally. We sought to evaluate trends in the prenatal detection of d-TGA with or without ventricular septal defect (VSD) in Alberta over the past 13 years, examining the potential impact of ultrasound guidelines incorporating screening of cardiac outflow tracts, updated in 2009-2010 and in 2013, and factors affecting detection of the condition.

METHODS

All fetuses and neonates with d-TGA, with or without VSD, encountered between 2003 and 2015 in the province of Alberta, were identified retrospectively. Clinical records including obstetric ultrasound reports were reviewed. Pregnancy outcome, common referral indications and associated maternal and fetal pathology in affected pregnancies were assessed.

RESULTS

From 2003 to 2015, 127 cases with d-TGA were encountered in Alberta, of which 47 (37%) were detected prenatally. Prenatal detection improved over the study period, from 14% in 2003-2010, to 50% in 2011-2013, and to 77% in 2014-2015. Of the 47 fetuses with a prenatal diagnosis of d-TGA, an indication for fetal echocardiography included abnormal or poorly visualized cardiac outflows with normal four-chamber view in 46 (98%). Comorbidities were identified in 12 mothers, only five of which represented an additional reason for fetal echocardiography referral, and four fetuses had extracardiac pathology.

CONCLUSION

Substantial improvement in the prenatal detection of d-TGA has been observed in Alberta over the past few years, owing to improved screening of cardiac outflow tracts on routine obstetric ultrasound examination in otherwise healthy pregnancies, and has been temporally associated with updated obstetric ultrasound guidelines suggesting that these contributed to optimized screening of affected pregnancies. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Parameters of fetal pulmonary vascular health: baseline trends and response to maternal hyperoxia in the second and third trimesters

OBJECTIVES

Several parameters, including branch pulmonary artery (PA) diameter and Doppler-derived PA acceleration-to-ejection time ratio (AT/ET), peak late-systolic/early-diastolic reversed flow (PEDRF) and pulsatility index (PI) response to maternal hyperoxia, have been used to investigate fetal pulmonary health. Lower AT/ET, increased PEDRF and lack of PI response to hyperoxia have been observed in fetuses with severe lung hypoplasia and are considered markers of pulmonary vascular resistance. We sought to further define the evolution of PA diameter and Doppler parameters and their response to maternal hyperoxia in healthy fetuses.

METHODS

Fifty-four prospectively recruited women with healthy pregnancy underwent fetal echocardiography from 18-36 weeks of gestation. After baseline branch PA diameter and Doppler assessment, oxygen (8-10 L/min) was administered by non-reservoir facemask for 10 min and PA Doppler parameters were reassessed.

RESULTS

Branch PA diameters and AT/ET increased linearly with gestational age, while PEDRF increased quadratically (P < 0.001 for all) and PA-PI did not change. In response to maternal hyperoxia, although most fetuses demonstrated a significant decrease in PI for both branch PAs (right PA, P = 0.025; left PA, P = 0.040) ≥ 30 weeks, significant variability was observed in PI response with 31% of cases demonstrating either no response or a slight decrease. No other parameter demonstrated a measurable change in response to maternal hyperoxia.

CONCLUSIONS

From the mid-trimester, fetal branch PA diameters and AT/ET increase linearly and PEDRF increases quadratically, whereas PI remains unchanged. Although maternal hyperoxia triggers a significant decrease in PA-PI after 30 weeks, variability in this response may reduce its utility in clinical practice. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Changes in fetal cardiac axis between 8 and 15 weeks' gestation

OBJECTIVES

To document changes in the normal embryonic/fetal cardiac axis in the late first and early second trimesters of pregnancy.

METHODS

Images from 188 fetal echocardiograms performed prospectively between 8 and 15 weeks' gestation in 166 healthy pregnancies and in 10 pregnancies with severe fetal heart disease were reviewed. For each echocardiogram, three measurements of the cardiac axis were taken in the axial plane at the level of the four-chamber view. Differences in mean embryonic/fetal cardiac axis at different gestational ages in the healthy pregnancies were compared.

RESULTS

The mean ± SD embryonic/fetal cardiac axis was 25.5 ± 11.5° from 8 + 0 to 9 + 6 weeks (Group  1), 40.4 ± 9.2° from 10 + 0 to 11 + 6 weeks (Group  2), 49.2 ± 7.4° from 12 + 0 to 12 + 6 weeks (Group  3), 50.6 ± 5.7° from 13 + 0 to 13 + 6 weeks (Group 4) and 48.6 ± 7.3° from 14 + 0 to 14 + 6 weeks (Group 5). Groups 1 and 2 were significantly different from each other and all other groups (P < 0.05). The results for 22 cases with repeat measurements from 8 + 0 to 11 + 6 and 12 + 0 to 14 + 6 weeks confirmed that the embryonic/fetal cardiac axis increased significantly (P < 0.001). In the cases with severe congenital heart disease, the cardiac axis was > 90th centile in four cases and < 10th centile in two cases.

CONCLUSIONS

The embryonic cardiac axis is relatively midline at 8 weeks and levorotates in the late first trimester. By 12 weeks' gestation, the normal leftward fetal cardiac axis is established and remains stable until at least 14 + 6 weeks. Observation of an abnormal cardiac axis in some cases of severe congenital heart disease prior to 15 weeks' gestation may assist in prenatal detection.

Severe left heart obstruction with retrograde arch flow influences fetal cerebral and placental blood flow

OBJECTIVE

Decreased middle cerebral artery (MCA) pulsatility index (PI) is a marker of fetal brain-sparing in placental insufficiency and it is also found in fetuses with severe congenital heart disease. This study sought to explore the impact of anatomical subtypes in fetal heart disease on MCA-PI and head growth.

METHODS

We retrospectively reviewed fetal echocardiograms of pregnancies complicated by fetal hypoplastic left heart syndrome (HLHS; n = 42) with and without anatomic coarctation (n = 28 and n = 10, respectively), isolated severe aortic coarctation (n = 21), D-transposition of the great arteries (TGA; n = 11) and pulmonary outflow tract obstruction without forward flow across the pulmonary valve (POTO; n = 15), comparing observations with gestational age-matched controls (n = 89). No fetus had major extracardiac pathology or aneuploidy. MCA and umbilical artery (UA) PI, the cerebral placental ratio (CPR  =  MCA-PI/ UA-PI) and neonatal head circumference were obtained and expressed as Z-scores.

RESULTS

Lower MCA-PI, higher UA-PI and lower CPR were observed in fetal HLHS and isolated coarctation with reversed arch flow (n = 6) (P < 0.001) but not TGA, POTO or isolated coarctation with antegrade arch flow (n = 15) compared with controls. No difference was found between HLHS with anatomical coarctation and those without; however, MCA-PI correlated positively with neonatal head circumference in HLHS with reversed distal arch flow (r = 0.33, P < 0.05).

CONCLUSIONS

Severe left heart obstruction with reversed aortic arch flow is associated with altered fetal cerebral blood flow, and in these conditions, MCA-PI positively correlates with head growth. Anatomical arch obstruction itself may not be a contributing factor to altered MCA flow in fetal HLHS.

Fetal cardiac function in recipient twins undergoing fetoscopic laser ablation of placental anastomoses for Stage IV twin-twin transfusion syndrome

OBJECTIVE

Cardiac dysfunction is common in the recipient fetus of twin-twin transfusion syndrome (TTTS). In this study, we aimed to document the severity of fetal cardiac dysfunction in Stage IV TTTS (fetal hydrops) and assess evolution of cardiac function longitudinally after fetoscopic laser surgery.

METHODS

We reviewed obstetric ultrasound examination data, pre- and postoperative echocardiograms and neonatal outcomes for 22 cases of Stage IV TTTS undergoing fetoscopic laser ablation of placental anastomoses between 1998 and 2011. Myocardial performance index, atrioventricular valve flow patterns, ventricular shortening fraction, ventricular hypertrophy, outflow tract obstruction and venous Doppler waveforms were assessed.

RESULTS

Nineteen fetuses (86.4%) had ascites, eight (36.4%) had pleural effusions, nine (40.9%) had a pericardial effusion and 12 (54.5%) had subcutaneous edema at presentation. Preoperatively, cardiac function was grossly abnormal in all. Eight fetuses (36.4%) had functional pulmonary atresia and one (4.5%) had functional aortic atresia. Seventy-seven percent of recipient fetuses survived until birth. Postoperative echocardiographic follow-up (mean, 26 days) showed that indices of fetal cardiac function improved considerably, but never completely normalized. Six of the eight fetuses with functional pulmonary atresia (75.0%), as well as the fetus with functional aortic atresia, survived to birth. In all cases, the functional atresia resolved within 48 h of laser ablation therapy and none had structural valve anomalies at birth. All fetal effusions resolved after the laser.

CONCLUSIONS

Fetoscopic laser ablation of placental anastomoses reverses cardiac dysfunction and valvulopathy, even in the most severe cases of TTTS. However, recovery takes longer than in early stage disease.

Effect of selective fetoscopic laser photocoagulation therapy for twin-twin transfusion syndrome on pulmonary valve pathology in recipient twins

OBJECTIVE

To investigate the impact of selective fetoscopic laser photocoagulation (SFLP) on pre-existing pulmonary valve pathology in the recipient twin in twin-twin transfusion syndrome (TTTS).

METHODS

We evaluated preoperative echocardiograms of all pregnancies with TTTS treated with SFLP at our institution from 2001 to 2009 (n = 76). Sixteen (21%) recipients had an abnormal pulmonary valve (stenosis/dysplasia, insufficiency or functional atresia) before SFLP. Postoperative echocardiograms and medical records from these 16 recipients were reviewed. Changes in pulmonary valve structure and function, and overall cardiac function, were noted after SFLP.

RESULTS

The mean gestational age at SFLP was 21 (range, 18.7-24.3) weeks. Seven of sixteen (44%) recipients with abnormal pulmonary valve prior to SFLP survived. Six of the 16 (37.5%) recipient twins had documented absence of persistent pulmonary valve abnormalities at birth or at autopsy. Two (12.5%) of the 16 recipients (2.6% of the original cohort) had persistent pulmonary valve abnormalities at birth, requiring intervention. Systolic and diastolic function improved or normalized after SFLP in all patients undergoing longitudinal follow-up. There was a tendency for a better cardiovascular profile score (best = 10 points) at initial evaluation in pregnancies with survivors compared with those with no survivors (mean (SD): 5.6 (2.2) vs. 6.75 (1.28)), but this was not statistically significant. Severity of cardiac involvement did not predict persistence of valve pathology or survival.

CONCLUSIONS

SFLP can improve flow through the pulmonary valve of the recipient twin in TTTS, probably as a consequence of improvements in right ventricular systolic and diastolic function. However, pulmonary valve pathology may persist and require postnatal intervention.

Spectrum of cardiac involvement in neonatal lupus

'Neonatal' lupus erythematosus (NLE) describes a clinical spectrum of cardiac and non-cardiac abnormalities observed in neonates and foetuses whose mothers have the auto-antibodies anti-SSA/Ro (anti-Ro) and anti-SSB/La (anti-La). Of the cardiac abnormalities, congenital AVB is the most common cardiovascular abnormality found in affected foetuses and infants. Many other cardiovascular manifestations of NLE have been more recently recognized including atrial and ventricular arrhythmias and other conduction abnormalities, myocarditis, cardiomyopathy often with endocardiofibroelastosis and structural heart disease, particularly valvar lesions. In this report, the spectrum of cardiovascular manifestations observed in foetuses and infants with NLE are reviewed and the pathogenesis, diagnosis and clinical outcomes are briefly discussed.

A case of restrictive cardiomyopathy presenting in fetal life with an isolated pericardial effusion

We describe the evolution during pregnancy of a case of restrictive cardiomyopathy which first presented at 22 weeks' gestation with a large pericardial effusion. Measurements of cardiac function were normal and remained near normal until late in the third trimester, when pulsed and tissue Doppler data suggested impairment in ventricular relaxation. This disease progressed in postnatal life to symptomatic restrictive cardiomyopathy by 2 years of age necessitating cardiac transplant. To our knowledge, this is the first time this unusual association has been reported.

Diffusion-weighted imaging in fetuses with severe congenital heart defects

Fetal diffusion MR imaging was performed in 3 fetuses with CHD. ADC values in the periatrial WM, thalamus, and basal ganglia were compared with those in a control population of fetuses. Diffusivity in the periatrial WM and thalamus was higher for the fetuses with CHD compared with controls. These observations support the finding of abnormal in utero brain development in fetuses with CHD.

Prenatal diagnosis of primary pulmonary hypoplasia in fraternal twins

Primary pulmonary hypoplasia is a rare, usually lethal, condition presenting only after birth without other congenital abnormalities. We describe the first case of fraternal twins diagnosed prenatally with primary pulmonary hypoplasia. Both had diffuse hypoplasia of the pulmonary arteries initially identified by fetal echocardiography and confirmed at autopsy following termination. These cases permit examination of the histopathology of this disease in the fetal stage of development.

Extracardiac lesions and chromosomal abnormalities associated with major fetal heart defects: comparison of intrauterine, postnatal and postmortem diagnoses

OBJECTIVES

The clinical outcome of prenatally diagnosed congenital heart defects (CHD) continues to be affected significantly by associated extracardiac and chromosomal abnormalities. We sought to: determine the frequency and type of major extracardiac abnormalities (with impact on quality of life) and chromosomal abnormalities associated with fetal CHD; and compare the extracardiac abnormalities detected prenatally to the postnatal and autopsy findings in affected fetuses, to find the incidence of extracardiac abnormalities missed on prenatal ultrasound.

METHODS

We reviewed the computerized database of the Division of Cardiology of the Hospital for Sick Children in Toronto to identify all cases of major CHD detected prenatally from 1990 to 2002. Medical records, fetal echocardiograms and ultrasound, cytogenetic and autopsy reports were reviewed. The types of CHD detected were grouped into categories and the frequencies of major extracardiac and chromosomal abnormalities in these categories were noted. Prenatal ultrasound findings were compared with those at autopsy or postnatal examination.

RESULTS

Of 491 fetuses with major structural CHD, complete data were obtained for 382. Of these, there were 141 (36.9%) with major extracardiac abnormalities at autopsy or postnatal exam, of which 46 had chromosomal abnormalities and 95 did not. In the absence of chromosomal abnormalities, the organ systems most affected were urogenital (12.2%) and gastrointestinal (11.6%). CHDs with the highest incidence of extracardiac abnormalities (>25%) included: heterotaxy, single left ventricle and tricuspid atresia, hypoplastic left heart syndrome and tetralogy of Fallot. Ninety-four of 334 (28.1%) fetuses tested had chromosomal abnormalities. The most common chromosomal abnormalities were trisomies 21 (43.6%), 18 (19.1%) and 13 (9.6%), monosomy X (7.4%) and 22q11.2 deletion (7.4%). Of 289 extracardiac abnormalities from the complete series, 134 (46.4%) were not identified prenatally. Of the missed extracardiac abnormalities, 65 were considered not detectable at prenatal ultrasound, so 23.9% (69/289) of detectable extracardiac abnormalities were missed prenatally.

CONCLUSIONS

Major extracardiac and chromosomal abnormalities are common in fetuses with major fetal CHD. Many important associated extracardiac abnormalities may be missed prenatally, which should be taken into consideration in the prenatal counseling for fetal CHD.

Color M-mode propagation velocity, but not its ratio to early diastolic inflow velocity, changes throughout gestation in normal human fetuses

OBJECTIVES

Color M-mode propagation velocity (Vp) is a measure of diastolic function in adults and, when combined with early diastolic inflow velocity (E), the ratio E/Vp reflects ventricular filling pressure. Early detection of diastolic compromise may benefit fetal patients at risk for developing heart failure. The objectives of this study were to measure values for Vp and inflow peak E in a group of normal fetuses, to analyze age-dependent alterations in these measurements, and to evaluate the interobserver and intraobserver variability of the measurements.

METHODS

Thirty-two normal fetuses at between 20 and 35 weeks' gestation underwent echocardiography. Color M-mode Vp was measured from the four-chamber view for the right (RV) and left (LV) ventricles, and mitral and tricuspid inflow velocities were determined by pulsed-wave Doppler ultrasound. The values obtained were compared with previously reported findings in adults.

RESULTS

Adequate tracings were obtainable in 23 patients for the RV and 29 for the LV. Mean Vp values for the RV (15.3 +/- 3.2 cm/s) and LV (20.8 +/- 5.6 cm/s) were lower than normal adult values, and Vp values were significantly lower for the RV than the LV (P < 0.001). Applying Bazett's heart rate correction, values for RV (23.4 +/- 4.8 cm/s) and LV (31.9 +/- 8.7 cm/s) remained lower than normal adult values. There was a linear correlation of Vp with gestational age for the RV (R = 0.69, P < 0.001), and the ratio of E/Vp corrected for heart rate for the RV (1.51 +/- 0.26) remained constant throughout gestation. Interobserver bias was high but intraobserver bias low, at 19 and 1.1%, respectively.

CONCLUSIONS

Vp is lower in fetal than in adult life. Vp for the RV changes in a manner indicative of improving diastolic function throughout normal gestation, providing insight into the alterations in diastolic function with gestation that contribute to increases in cardiac output. The use of Vp to assess diastolic function disturbance in fetuses is feasible, but high interobserver variability is problematic.

Diameter of the normal fetal thymus on ultrasound

OBJECTIVE

To present the normative data of the transverse diameter of the developing fetal thymus.

METHODS

In this prospective study, the maximum transverse diameter of the thymus was measured by one sonologist in 376 normal fetuses between 19 and 38 weeks of gestation. We assessed the relationship of the transverse thymic diameter with gestational age (GA), biparietal diameter, femur length and abdominal circumference using general linear regression modeling. The predicted mean and 95% reference range of thymic diameter at each GA were calculated from the regression equation.

RESULTS

Measurements of the transverse diameter were possible in 352 of the 376 (94%) fetuses. The transverse diameter of the fetal thymus increased with increasing GA and fetal size parameters in a linear manner. The regression equation for transverse diameter of the thymus as a function of GA was: thymic diameter (cm) = 0.15 x GA (weeks) - 1.59 (r(2) = 0.86, P < 0.001).

CONCLUSION

The transverse diameter of the fetal thymus is easy to measure; this study presents normative data.

Maternal diabetes and the fetal heart

Maternal diabetes mellitus significantly affects the fetal heart and fetal-placental circulation in both structure and function. The influence of pre-conceptional diabetes begins during embryonic development in the first trimester, with altered cardiac morphogenesis and placental development. It continues to have an influence on the fetal circulation through the second and third trimesters and into the perinatal and neonatal period.

Fetal cardiac calcifications: report of four prenatally diagnosed cases and review of the literature

Fetal cardiac calcifications are defined as diffuse hyperechogenicities in the different layers of the heart. This is an uncommon fetal ultrasound finding associated with significant myocardial dysfunction. We report four cases with massive fetal myocardial calcifications detected on prenatal ultrasound at 18-22 weeks' gestation and associated, in all cases, with significant cardiac dysfunction. Detailed fetal echocardiographic evaluation, chromosome analysis, and an extensive search for intrauterine infection as a cause of these abnormalities, were carried out on all cases. A thorough autopsy was performed on all deceased fetuses and postnatal investigation of the sole survivor was performed. Two of our patients chose to interrupt their pregnancies, one fetus suffered intrauterine demise, and one child was born alive. In all of our cases the karyotypes were normal, and no specific infectious etiology or maternal autoantibody was noted. Histopathology findings in the non-survivors included myo- and epicardial calcification maximal at the base of the heart. The living child has findings suggestive of an intrauterine infection, although no infectious entity was identified. Long-term follow-up showed sensorineural hearing loss and severe developmental delay.

Development of Z-scores for fetal cardiac dimensions from echocardiography

OBJECTIVES

Z-scores for cardiac dimensions are well established in postnatal life, but have yet to be developed for fetal cardiac dimensions. These would be of real advantage to the clinician in accurately quantifying size and growth of cardiac dimensions and to the researcher by allowing mathematical comparison of growth in differing subgroups of a disease. The purpose of this observational study, conducted at tertiary fetal medicine and cardiology units, was to produce formulae and nomograms allowing computation of Z-scores for fetal cardiac dimensions from knowledge of femur length (FL), biparietal diameter (BPD) or gestational age (GA) using fetal echocardiography.

METHODS

Seventeen fetal cardiac dimensions were measured in 130 pregnant women with singleton fetuses of gestational age 15-39 weeks. Regression equations were derived relating all dimensions to FL, BPD and GA. From the calculations, formulae were then developed allowing fetal cardiac Z-score computation.

RESULTS

The relationships between cardiac dimensions and FL, BPD or GA were described following natural log transformation. From this analysis, FL (taken as an expression of fetal size) had the highest correlation to fetal cardiac dimensions. From the developed nomograms, Z-scores of specific fetal cardiac structures could be estimated from knowledge of the FL, BPD or GA and echocardiographically derived measurements.

CONCLUSIONS

This study allowed computation of Z-scores in fetal life for 17 cardiac dimensions from FL, BPD or GA. Previous studies of normal data allowed qualitative assessment of where abnormal cardiac dimensions lay with regard to the normal range. Z-scores from this study allow quantitative analysis of where such dimensions lie relative to the mean. This permits exact assessment of growth of fetal cardiac structures in normal hearts and particularly in congenitally abnormal hearts where quantitative assessment of the growth of cardiac structures is important in analyzing and planning treatment strategies.

Effects of maternal hyperoxia with and without normocapnia in uteroplacental and fetal Doppler studies

OBJECTIVE

One hundred percent oxygen is given in pregnancy to improve fetal oxygenation, yet has been shown in both animal and human studies ex utero to increase cerebral vascular resistance. Adjusting end-tidal pCO2 (ET-pCO2) levels to normocapnic levels during hyperoxygenation offsets this effect in non-pregnant individuals. We aimed to evaluate the effect of maternal hyperoxygenation with and without maintaining normocapnia on the fetal and uteroplacental circulations in healthy near-term human pregnancies.

METHODS

Eight healthy pregnant women, serving as their own controls, sequentially breathed room air, breathed 100% oxygen, and underwent normocapnic hyperoxygenation (NH) in a three-phase experiment involving a tight-fitting facemask. Each phase lasted 10-15 min. After steady state had been reached, peak velocities and pulsatility index (PI) values were obtained from the uterine, umbilical and fetal middle cerebral arteries (MCA) by color/pulsed Doppler. In addition, maternal ventilation and ET-pCO2 were monitored.

RESULTS

One hundred percent oxygen induced maternal hyperventilation and hypocapnea. Uterine artery PI and peak systolic velocities were stable during 100% oxygen. In contrast, during NH uterine artery PI values decreased by 21% (P=0.04). Umbilical artery PI and peak velocities were stable during 100% oxygen; PI increased by 16% during NH (P=0.056), with no change in peak velocities. Peak MCA velocities decreased by 8% during 100% oxygen, and by 9.6% during NH, while MCA-PI decreased by 13% during 100% oxygen and by 21% during NH (P=0.06).

CONCLUSIONS

Maternal and fetal circulations exhibit divergent responses to 100% oxygen and NH. While no change is observed in the uteroplacental circulation on 100% oxygen, decreased resistance and increased flow velocity are evident during NH. Increased umbilical artery PI during NH with no change in absolute velocities may suggest a reduction in fetoplacental blood flow. Maintaining normocapnia during hyperoxygenation does not appear to beneficially influence the circulation of the near-term human fetus as it does in non-pregnant individuals.

Cardiac function assessment in patients with family history of nonhypertrophic cardiomyopathy: a prenatal and postnatal study

Nonobstructive cardiomyopathies (CMs) may be familial in 20â<euro>"55% of cases. Little is known about the role of fetal echocardiography in such cases. We evaluated the cardiac function serially pre- and postnatally in cases with a family history of nonobstructive CM. The fetal and postnatal studies were performed in the echocardiogarphy laboratory at a tertiary institution. Twenty-six cases from 16 families with a family history of CM were studied. Three fetal echocardiograms were performed at or near 18, 25, and 32 weeks of gestation for complete cardiac functional assessment. Postnatally clinical evaluation, electrocardiogram, and an echocardiogram were performed within the first 3 months, with serial reevaluation for those identified with CM. The mean follow-up was 46 +/- 9 months. Abnormal cardiac function was observed in 8 cases (30%). Six had a previously affected sibling, 1 had other family members affected, and 1 had both antecedents. Four had dilated CM diagnosed prenatally of which 1 recovered, 2 died in utero, and 1 died soon after birth. The remaining 4 had normal fetal echoes and were diagnosed with CM in the first 3 months of life. Three had dilated CM with recovery, and 1 had restrictive CM requiring cardiac transplantation. This study demonstrates a high familial recurrence rate of CM. Fetal echo is useful for early diagnosis, although a normal study does not preclude ventricular dysfunction at a later stage, justifying serial prenatal and postnatal evaluation. Early identification may expedite listing for transplantation.

Prenatal diagnosis of complete atrioventricular block associated with structural heart disease: combined experience of two tertiary care centers and review of the literature

OBJECTIVE

To review the pattern of presentation, management and outcome of fetal complete atrioventricular block (CAVB) associated with major structural congenital heart disease (CHD), when compared to isolated CAVB.

METHODS

Retrospective analysis of the medical records and echocardiograms of all CAVB cases, diagnosed prenatally at two tertiary care centers between the years 1990 and 2002.

RESULTS

Of a total of 59 consecutive fetal cases of CAVB, 24 (41%) had underlying major CHD, mainly left isomerism (n = 18) and congenitally corrected transposition of the great arteries (cc-TGA) (n = 3). When compared to isolated CAVB (n = 35), cases with CHD were detected earlier (21 +/- 6 vs. 26 +/- 6 weeks; P < 0.02) and-despite comparable heart rates-more often had fetal hydrops (38% vs. 9%; P < 0.02), while pregnancy continuation (66% vs. 94%; P < 0.02) or prenatal treatment (19% vs. 64%; P < 0.001) was less likely. Of 16 CHD cases with pregnancy continuation, beta-inotropic treatment of fetal bradycardia was attempted in three cases: all had left isomerism and died early postnatally. Livebirth and 1-year survival rates of CAVB with CHD were 56% and 19%, respectively, when compared to isolated CAVB with 88% and 75%, respectively (P < 0.0001). The four neonatal survivors (one left isomerism, three cc-TGA) had heart rates persistently > 60 bpm throughout gestation and 3/4 underwent a biventricular repair.

CONCLUSIONS

Fetal CAVB with CHD continues to be associated with a poor outcome, in particular in the presence of left isomerism and fetal heart rates < 60 bpm.

Cardiac diverticulum with pericardial effusion: report of two new cases treated by in-utero pericardiocentesis and a review of the literature

Congenital cardiac diverticula are rare abnormalities that may occur as isolated malformations. They are often associated with pericardial effusions, which may cause both pulmonary hypoplasia and progressive fetal hydrops. Few cases are reported in fetal life. Mount Sinai Hospital, Toronto, has previously reported two cases of cardiac diverticula complicated with pericardial effusion successfully treated in utero with aspiration of the pericardial fluid. Here a further two cases of isolated apical right ventricular diverticula with large pericardial effusion, one diagnosed at 16 weeks and another at 13 weeks' gestation are described. In-utero drainage of pericardial effusion was performed once in each case at 16 and 14 weeks' gestation, respectively, with good neonatal outcome. Both had normal karyotype and there was no evidence of maternal or fetal infection. The pericardial effusion did not recur in either case. Given the otherwise favorable prognosis for this lesion, and the excellent response in these cases, prenatal pericardiocentesis should be considered in similar cases.

Evolution of heart disease in utero

Cardiac embyogenesis occurs in the first 6 to 7 weeks of human development. Although it is during this time that many of the major cardiovascular defects develop, many of these lesions continue to evolve and others develop in the latter half of gestation. There may be development or progression of ventricular inflow or outflow tract and arch obstruction, and ventricular or great artery hypoplasia. There may be progressive antrioventricular or semi-lunar valve regurgitation which can compromise the fetal circulation. There may be development of dysrhythmias, primary myocardial disease and heart failure. The fetal shunts, the foramen ovale and ductus arteriosus, may change in form and function. Finally, cardiac tumors may develop, grow, or regress. Knowledge of the mechanisms of and potential for progression in fetal heart disease is critical for counseling regarding prognosis and for planning of prenatal and neonatal management.

Partial and total anomalous pulmonary venous connection in the fetus: two-dimensional and Doppler echocardiographic findings

OBJECTIVE

Prenatal diagnosis of total (TAPVC) or partial (PAPVC) anomalous pulmonary venous connection in isolation or associated with other cardiac disease is important for appropriate prenatal counseling and perinatal management. We sought to assess the echocardiographic clues to the fetal diagnosis of TAPVC and PAPVC in a cohort of affected fetuses.

METHODS

We retrospectively reviewed 29 fetal echocardiograms performed in 16 pregnancies with fetal TAPVC or PAPVC, systematically analyzing heart chamber size, presence of a confluence behind the left atrium or of a vertical vein, and Doppler flow patterns.

RESULTS

Prenatal diagnosis was made at a mean gestational age of 27 +/- 7 weeks. TAPVC was found in 11 cases; five cases for each of supracardiac and infracardiac types and one mixed type. PAPVC was diagnosed in five fetuses, four of which had scimitar syndrome. Ten fetuses had an additional major cardiac defect, including hypoplastic left heart syndrome and right atrial isomerism. In three cases the prenatal diagnosis was only made at follow-up assessment. Among TAPVC cases, visualization of a confluence behind the left atrium (10/11) and a vertical vein (11/11) were the most consistent echocardiographic clues. Dextrocardia and a small right pulmonary artery suggested scimitar syndrome. The diagnosis was confirmed postnatally or at autopsy in 12 cases. In six fetuses with TAPVC and obstruction confirmed postnatally, continuous turbulent flow in the vertical vein and monophasic continuous flow in the pulmonary veins were demonstrated by color and spectral Doppler.

CONCLUSIONS

Fetal echocardiography permits prenatal diagnosis of TAPVC or PAPVC. Spectral and color Doppler provide clues to the presence of an obstructed pulmonary venous pathway.

Diagnosis, natural history, and outcome of fetal heart disease

Advances in the prenatal diagnosis of heart disease have improved accuracy in the evaluation of structural heart lesions, dysrhythmia mechanisms, and functional pathology and will lead to better perinatal management and counseling. Additional technical advances will lead to earlier diagnosis, perhaps even during embryonic development. Newer developments, including the transumbilical and transuterine approaches, may make antenatal intervention possible and safer for a larger number of affected pregnancies.

Acquired right ventricular outflow tract obstruction in the recipient twin in twin-twin transfusion syndrome

OBJECTIVES

The goal of this study was to determine the prevalence and evolution of acquired right ventricular outflow tract obstruction (RVOTO) in the recipient twin in twin-twin transfusion syndrome (TTTS).

BACKGROUND

Twin-twin transfusion syndrome complicates 4% to 26% of diamniotic monochorionic twin gestations and is associated with high fetal morbidity and mortality. Cardiac dysfunction and biventricular hypertrophy may develop in the recipient twin with the potential for RVOTO.

METHODS

This was a retrospective review of a two-center experience of TTTS to describe the prevalence and evolution of acquired RVOTO in the recipient twin. Right ventricular outflow tract obstruction was diagnosed or excluded by fetal or postnatal echocardiography or clinical assessment.

RESULTS

Of 73 twin pregnancies with TTTS identified between 1994 to 1998, a total of seven (9.6%) were complicated by RVOTO in the recipient twin: two subvalvar/muscular, four valvar and one combined. Of 44 pregnancies with fetal echo, six had in utero RVOTO with antegrade flow diagnosed at gestational ages ranging from 19 to 27 weeks. In utero progression occurred in four cases over a period of four to eight weeks, with the development of RVOT atresia by delivery. Postnatal progression of RVOTO occurred in two cases, one of which required pulmonary balloon valvuloplasty at age two years. Postnatal regression of subvalvar RVOTO occurred in two cases in early infancy. Death related directly or indirectly to the RVOTO occurred in all four patients who developed complete RVOT obliteration.

CONCLUSIONS

Right ventricular outflow tract obstruction may occur in the recipient twin of at least 9% of pregnancies complicated by TTTS. Right ventricular outflow tract obstruction progression is common in utero and may worsen neonatal outcome.

Bilateral congenital diaphragmatic hernia: diagnostic clues at fetal sonography

Bilateral congenital diaphragmatic hernia is a rare, life-threatening malformation. We describe a case of bilateral Bochdalek hernia diagnosed prenatally. The sonographic clues to the diagnosis were anterior displacement of the heart with relatively minimal lateral shift. The definitive diagnosis was made by demonstrating the liver in the right thorax and bowel loop and stomach in the left thorax. Color and power Doppler demonstrated the hepatic vessels embracing both sides of the heart from behind.

Precoronary stenosis after stage I palliation for hypoplastic left heart syndrome

We report a patient with stenosis of the native ascending aorta after palliation of hypoplastic left heart syndrome and aortic atresia. We describe the approach to diagnosis, temporary support with extracorporeal membrane oxygenation, and successful surgical reintervention. Stenosis of the native ascending aorta is an important, potentially reversible cause of acute, early postoperative ventricular dysfunction.

Cardiac structure and function in fetuses of mothers infected with HIV: the prospective PCHIV multicenter study

BACKGROUND

This study was designed to determine if vertically transmitted HIV infection and maternal infection with HIV are associated with altered cardiovascular structure and function in utero.

METHODS

Fetal echocardiography was performed in 173 fetuses of 169 HIV-infected mothers (mean gestational age, 33.0 weeks; SD = 3.7 weeks) at 5 centers. Biparietal diameter, femur length, cardiovascular dimensions, and Doppler velocities through atrioventricular and semilunar valves and the umbilical artery were measured. Measurements were converted to z scores based on published normal data.

RESULTS

Fetuses determined after birth to be HIV-infected had similar echocardiographic findings as fetuses later determined to be HIV-uninfected except for slightly smaller left ventricular diastolic dimensions (P =.01). The femur length (P =.03) was also smaller in the fetuses postnatally identified as HIV-infected. Differences in cardiovascular dimensions and Doppler velocities were identified between fetuses of HIV-infected women and previously published normal fetal data. The reason for the differences may be a result of maternal HIV infection, maternal risk factors, or selection bias in the external control data.

CONCLUSIONS

Vertically transmitted HIV infection may be associated with reduced left ventricular size but not with altered cardiac function in utero. Fetuses of HIV-infected mothers may have abnormal cardiovascular structure and function and increased placental vascular resistance, regardless of whether the fetuses are subsequently found to be infected with HIV.

Fetal cardiac dextroposition in the absence of an intrathoracic mass: sign of significant right lung hypoplasia

We reviewed our experience of fetal cardiac dextroposition in the absence of an intrathoracic mass. Ten cases were found by fetal echocardiography to have a normal cardiac axis, but the heart was shifted into the right chest and the amount of right lung tissue was reduced. At birth seven of the infants had confirmed structural heart disease (70%), including three with scimitar syndrome. Two infants had additional extracardiac anomalies (20%). Seven infants born at term had clinical pulmonary hypertension with a diagnosis of right lung hypoplasia in all of them. Two neonates died owing to significant heart disease (one with scimitar syndrome and the other with hypoplastic left heart syndrome). Of the three pregnancies that were terminated, the two fetuses with autopsies had severe right lung hypoplasia. Fetal cardiac dextroposition and right pulmonary artery hypoplasia in the absence of an intrathoracic mass are important signs of right lung hypoplasia, which can be associated with significant pathologic cardiac and extracardiac conditions.

Synthesis of extracellular matrix and adhesion through beta(1) integrins are critical for fetal ventricular myocyte proliferation

Extracellular matrix (ECM) regulates vascular smooth muscle cell proliferation. The role of ECM in myocardial growth is unexplored. We sought to determine whether human fetal ventricular myocytes (HFVMs) produce ECM and whether synthesis and attachment to ECM are necessary for their epidermal growth factor (EGF)-dependent and -independent proliferation. Cultured HFVMs proliferate in the presence but not absence of serum and EGF, as determined by increase in cell number and [(3)H]thymidine and [(14)C]leucine incorporation (measures of DNA and protein synthesis, respectively). Using a cyanogen bromide digestion technique to measure collagen and elastin and using affinity chromatography for fibronectin, we found that HFVMs synthesized collagen and fibronectin but not elastin. HFVMs grown on exogenous ECM (including fibronectin and type I collagen and laminin) demonstrated no change in proliferation or DNA and protein synthesis with or without EGF. However, inhibition of collagen synthesis using cis-4-hydroxyproline resulted in a decrease in EGF-related HFVM proliferation and DNA and protein synthesis, which was reversed by exposure to L-proline but not by growth on type I collagen. Use of beta(1) but not beta(3) integrin antibody to inhibit cell interaction with ECM resulted in a decrease in HFVM proliferation and DNA and protein synthesis in response to EGF. Furthermore, EGF-dependent proliferation was enhanced by alpha(1)beta(1) and alpha(5)beta(1) antibodies that act as functional ligands, but not alpha(3)beta(1), the only beta(1) subtype expressed in adult myocytes. In conclusion, proliferating HFVMs synthesize collagen and fibronectin. The proliferative response of HFVMs to EGF requires the synthesis of collagen as well as attachment to specific alpha/beta(1) integrin heterodimers.

Isolated ductus arteriosus aneurysm in the fetus and infant: a multi-institutional experience

OBJECTIVES

The purpose of this study was to describe the clinical characteristics and outcome and to elucidate the pathogenesis of ductus arteriosus aneurysm (DAA).

BACKGROUND

Ductus arteriosus aneurysm is a rare lesion that can be associated with severe complications including thromboembolism, rupture and death.

METHOD

We reviewed the clinical records, diagnostic imaging studies and available histology of 24 cases of DAA, diagnosed postnatally (PD) in 15 and antenatally (AD) in 9 encountered in five institutions.

RESULTS

Of PD cases, 13 presented at <2 months, and all AD cases were detected incidentally after 33 weeks of gestation during a late trimester fetal ultrasound study. Of the 24, only 4 had DAA-related symptoms and 6 had associated syndromes: Marfan, Smith-Lemli-Opitz, trisomies 21 and 13 and one possible Ehlers-Danlos. Three had complications related to the DAA: thrombus extension into the pulmonary artery, spontaneous rupture, and asymptomatic cerebral infarction. Six underwent uncomplicated DAA resection for ductal patency, DAA size or extension of thrombus. In the four examined, there was histologic evidence of reduced intimal cushions in two and abnormal elastin expression in two. Five of the 24 died, with only one death due to DAA. Of 19 survivors, all but one remain clinically asymptomatic at a median follow-up of 35 months; however, two have developed other cardiac lesions that suggest Marfan syndrome. A review of 200 consecutive third trimester fetal ultrasounds suggests an incidence of DAA of 1.5%.

CONCLUSIONS

Ductus arteriosus aneurysm likely develops in the third trimester perhaps due to abnormal intimal cushion formation or elastin expression. Although it can be associated with syndromes and severe complications, many affected infants have a benign course. Given the potential for development of other cardiac lesions associated with connective tissue disease, follow-up is warranted.

Diagnosis of left juxtaposition of the atrial appendages in the fetus

We describe two cases of left juxtaposition of the atrial appendages in which fetal echocardiograms provided a clue to the diagnosis. Both cases were associated with complex cyanotic congenital heart disease. The clue to the diagnosis was found at the three-vessel view. Abnormal vascular spaces were seen on the left side of the cross-sections of the great arterial trunks.

Echocardiographic predictors of outcome in newborns with congenital diaphragmatic hernia

OBJECTIVE

Despite new treatments, congenital diaphragmatic hernia (CDH) still has high mortality. The aim of this study was to identify echocardiographic predictors of outcome in newborns with an isolated CDH.

METHODS

We reviewed medical charts and echocardiograms of 40 newborns who presented with CDH in the first 24 hours of life, from 1992 to 1996. We compared the cardiac valves and great arteries diameters, left-ventricular volume and mass, Apgar scores, and modified McGoon index (the combined diameter of hilar pulmonary arteries, indexed to the descending aorta) of survivors and nonsurvivors. We performed Student's t test and multiple logistic regression analysis between the 2 groups.

RESULTS

Fourteen patients died 1 to 33 days after birth (median: 3 days), including 8 from progressive hypoxemia without operation; 26 have survived up to 5 years (median: 2 years) after successful operations. Nonsurvivors had significantly smaller diameters of right and left hilar pulmonary arteries, more frequent right-sided CDH, and lower mean Apgar scores at 1 and 5 minutes. The most significant prognostic factor was the modified McGoon index. A modified McGoon index </=1.3 predicted mortality with a sensitivity of 85% and specificity of 100%.

CONCLUSION

Echocardiographic measurement of hilar pulmonary arteries, which may represent the adequacy of the pulmonary vascular bed, is a strong prognostic factor for newborns with congenital CDH.

Isolated origin of the left subclavian artery from the left pulmonary artery

We describe two children with isolated origin of the left subclavian artery from the left pulmonary artery detected by echocardiography during the assessment of their congenital cardiac malformations. Both patients demonstrated pre-operative evidence of subclavian steal. This entity results from persistence of the dorsal segment of the sixth left arch, with regression of the left fourth arch and interruption of the left dorsal arch distal to the origin of the seventh left intersegmental artery. The significance of this finding relates to the potential for pulmonary overcirculation, which could have significant post-operative ramifications if not detected prior to surgical repair of an associated cardiac malformation. This entity differs from cases with a right aortic arch and aberrant left subclavian artery which has the potential to form a vascular ring, unlike cases with isolated origin of the left subclavian artery from the pulmonary artery that do not cause compression of the airway.

De novo 46,XX,t(6;7)(q27;q11;23) associated with severe cardiovascular manifestations characteristic of supravalvular aortic stenosis and Williams syndrome

Supravalvular aortic stenosis may present as an isolated finding or as part of Williams syndrome. Williams syndrome is a contiguous gene syndrome associated with neurodevelopmental and multisystemic manifestations caused by hemizygous deletion at 7q11.23. We report on the prenatal and histopathological findings in a patient with a chromosome translocation involving the Williams syndrome critical region. The initial abnormality on fetal ultrasound was hydrops fetalis detected at 30 weeks and echocardiography showed narrowing of the aorta and the pulmonary arteries. The baby died shortly after delivery and an autopsy revealed diffuse tubular thickening with luminal narrowing of the aorta, aortic branches, and the pulmonary arteries. Histopathology showed dysplasia of the media with reduced elastic content and "cartwheel" arrangement of collagen, elastic, and muscle fascicles. The karyotype was 46,XX,t(6;7)(q27;q11.23). Three signals were detected using the Oncor fluorescent in situ hybridization probe for elastin-Williams syndrome (WSCR) suggesting that the break in chromosome 7 is within the elastin-Williams gene. This patient is of special interest because of the prenatal presentation and the chromosomal translocation involving the elastin-Williams syndrome locus.

Preservation of the pulmonary valve complex in tetralogy of fallot: how small is too small?

BACKGROUND

Surgical repair of congenital lesions associated with right ventricular outflow tract obstruction frequently requires the destruction of pulmonary valve (PV) components including the valve annulus. The resultant pulmonary insufficiency may lead to late functional deterioration of right ventricular performance. Acute right ventricular dysfunction has been associated with poor pulmonary runoff, tricuspid valve regurgitation, and pulmonary hypertension. Preservation of PV competence may prevent both early and late right ventricular failure. However, the recent trend towards earlier repair of tetralogy of Fallot (TOF) may preclude preservation of the PV in favor of a transannular patch. We reviewed our experience with surgical repair of TOF to determine if age and/or body size affected the ability to repair the PV.

METHODS

We reviewed the clinical records of 50 consecutive children who underwent surgical repair of TOF by one surgeon. The latter 27 patients underwent repair with an intention to preserve their pulmonary valve. In total, 28 patients underwent repair with preservation of their pulmonary valve, and form the basis of this study. Serial echocardiographic assessments were performed early (3 to 6 months) and late (12 months) after surgery.

RESULTS

Pulmonary valve preservation was possible in the majority of children (89%) in whom it was intended. Pulmonary valve competence was observed in 68% of children, with only 5 (16%) children demonstrating severe insufficiency at follow-up. Residual right ventricular outflow tract obstruction was present in only 1 child who underwent repair with pulmonary valve preservation at greater than 2 years of age.

CONCLUSIONS

Our data suggest that earlier repair of TOF does not preclude preservation of the pulmonary valve and may indeed facilitate repair. The pulmonary valve remains competent at 12 months, with acceptable gradients, and should participate in somatic growth. Pulmonary valve preservation during repair of TOF may prevent free pulmonary insufficiency, progressive right ventricular dilation, and the need for future prosthetic pulmonary valve replacement.

Presentation and outcomes of ectopia cordis

BACKGROUND

Ectopia cordis, defined as complete or partial displacement of the heart outside the thoracic cavity, is rare. The cause and pathogenesis are unknown. The anatomy of the heart may be normal, but the presence of structural heart disease as well as noncardiac malformations is common. Patients present incidentally after birth or, more recently, the condition has been diagnosed by prenatal echocardiography.

OBJECTIVE

To review the presentation, diagnostic imaging, management and outcomes of infants with ectopia cordis at The Hospital for Sick Children, Toronto, Ontario.

METHODS

The medical records of the database of the Division of Cardiology, The Hospital for Sick Children, were searched; echocardiograms, and surgical and autopsy reports were further reviewed.

RESULTS

Between 1978 and 1998, 10 patients with ectopia cordis presented to the authors' centre. Normal cardiac anatomy was noted in three, and mild to complex structural cardiac anomalies were noted in the remainder. Associated noncardiac malformations were found in six cases. Six were diagnosed by prenatal ultrasound between 19 and 37 weeks of gestation. Pregnancies were electively terminated or the infants died shortly after birth. Four other neonates with ectopia cordis were referred to the authors' centre. All of these infants subsequently died either at the time of surgery for cardiac and noncardiac anomalies or in the immediate postoperative period.

CONCLUSIONS

Despite modern treatment options, the mortality remains high for patients with ectopia cordis, especially in the presence of structural heart disease or other malformations.

Comparison of outcome when hypoplastic left heart syndrome and transposition of the great arteries are diagnosed prenatally versus when diagnosis of these two conditions is made only postnatally

We sought to determine the impact of prenatal diagnosis on the perioperative outcome of newborns with hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA). All neonates with HLHS or TGA encountered at Children's Hospital, Boston, Massachusetts, from January 1988 to May 1996 were identified and outcomes documented. Birth characteristics, preoperative, operative, and postoperative variables of term newborns with a prenatal diagnosis of HLHS or TGA who underwent a Norwood operation (n = 27) or arterial switch operation (n = 14), respectively, were compared with newborns with a postnatal diagnosis of HLHS (n = 47) or TGA (n = 28) who had undergone surgery. Of 217 neonates with HLHS and 422 with TGA, 39 and 16, respectively, had a prenatal diagnosis. The preoperative mortality among neonates aggressively managed did not differ between the prenatal and postnatal diagnosis groups for either HLHS or TGA (p >0.05). Neonates with a prenatal diagnosis who underwent surgery had objective indicators of lower severity of illness preoperatively, including a higher lowest recorded pH (p = 0.03), lower maximum blood urea nitrogen (p = 0.002), and creatinine (p = 0.03) among newborns with HLHS, and a tendency toward higher minimum of partial pressure of arterial oxygen in the TGA group (p = 0.06). Prenatal diagnosis was not associated with an improved postoperative course or operative mortality (p <0.05) within a diagnostic group. Thus, a prenatal diagnosis improves the preoperative condition of neonates with HLHS and TGA, but may not significantly improve preoperative mortality or early postoperative outcome among neonates managed at a tertiary care center.