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.

Inadvertent irreversible closure of arterial duct following therapeutic use of transplacental indomethacin in a fetus with severe Ebstein's anomaly and circular shunt

We report on a fetal case of Ebstein's anomaly with severe tricuspid regurgitation, functional pulmonary atresia and progressive circular shunting (CS) across a widely patent ductus arteriosus (DA) and regurgitant pulmonary valve, contributing to significant systemic hypoperfusion. To mitigate the extent of CS and allow the pregnancy to continue, maternal non-steroidal anti-inflammatory drug (NSAID) therapy with indomethacin was started at 33 + 5 weeks to induce DA constriction. Rather than achieving the desired narrowing of the DA, the treatment led to its complete closure and only minimal antegrade flow across the pulmonary valve. While closure of the DA resulted in the anticipated improvement in fetal hemodynamics, at birth, the child was at risk of severe hypoxemia and its consequences due to the lack of adequate pulmonary perfusion. Reduction and eventual discontinuation of the NSAID treatment did not result in DA reopening. Our experience illustrates the risk of unintended irreversible DA closure when NSAIDs are used to treat CS. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

MRI characterization of hemodynamic patterns of human fetuses with cyanotic congenital heart disease

OBJECTIVES

To characterize, using magnetic resonance imaging (MRI), the distribution of blood flow and oxygen transport in human fetuses with subtypes of congenital heart disease (CHD) that present with neonatal cyanosis.

METHODS

Blood flow was measured in the major vessels of 152 late-gestation human fetuses with CHD and 40 gestational-age-matched normal fetuses, using cine phase-contrast MRI. Oxygen saturation (SaO₂ ) was measured in the major vessels of 57 fetuses with CHD and 40 controls.

RESULTS

Compared with controls, we found lower combined ventricular output in fetuses with single-ventricle physiology, with the lowest being observed in fetuses with severe forms of Ebstein's anomaly. Obstructive lesions of the left or right heart were associated with increased flow across the contralateral side. Pulmonary blood flow was reduced in fetuses with Ebstein's anomaly, while those with Ebstein's anomaly and tricuspid atresia had reduced umbilical flow. Flow in the superior vena cava was elevated in fetuses with transposition of the great arteries, normal in fetuses with hypoplastic left heart, tetralogy of Fallot or tricuspid atresia and reduced in fetuses with Ebstein's anomaly. Umbilical vein SaO₂ was reduced in fetuses with hypoplastic left heart or tetralogy of Fallot. Ascending aorta and superior vena cava SaO₂ were reduced in nearly all CHD subtypes.

CONCLUSIONS

Fetuses with cyanotic CHD exhibit profound changes in the distribution of blood flow and oxygen transport, which result in changes in cerebral, pulmonary and placental blood flow and oxygenation. These alterations of fetal circulatory physiology may influence the neonatal course and help account for abnormalities of prenatal growth and development that have been described in newborns with cyanotic CHD. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Prenatal diagnosis of vascular ring: evaluation of fetal diagnosis and postnatal outcomes

Funding Acknowledgements

Type of funding sources: None.

Background

The performance of fetal echocardiogram in diagnosing vascular ring (VR) and its impact on postnatal outcomes has not been well examined.

Methods

We reviewed all patients with VR diagnosis from 2000-2020.

Results

50 patients with antenatal diagnosis of VR; 42(84%) with right aortic arch aberrant left subclavian artery and left-sided ductus arteriosus ((RAA-ALS) and 8(16%) with double aortic arch (DAA) were compared to 120 patients with postnatal diagnosis; 90(75%) with DAA, 22(18%) with RAA-ALS (Table 1). Prenatal diagnosis of VR increased over study period; 4 vs 31, 10 vs 29, 14 vs 25, 22 vs 35 between 2000-2005, 2005-2010, 2010-2015, and 2015-2020 respectively, p< 0.01. Prenatal diagnosis of VR was associated with less symptoms [26(52%) vs 72(60%), p < 0.003] and less cross-sectional imaging [22(44%) vs 82(69%), p = 0.0001]. Postnatal diagnosis of VR was associated with more surgical interventions (102(85%) vs 28(56%), p = 0.002), later surgical repair (22.9 ± 35 vs 12.6 ± 10.2 months, p < 0.01), more postoperative complications [8/102 (7.8%) vs 1/28 (3.5%), p = 0.04] and more residual symptoms (2/28(7%) vs 30/102(29%), p = 0.001 respectively].

Conclusion

Prenatal diagnosis of VR has evolved over time. RAA-ALS versus DAA were dominant in the prenatally and postnatally diagnosed cohorts respectively. Prenatal diagnosis of VR was associated less symptoms, less cross-sectional imaging, earlier age of surgical intervention and less residual symptoms.

Table 1 Prenatal Diagnosis (N = 50) Postnatal Diagnosis (N = 120) p-value Gestational Age (weeks) 39 ± 3 38 ± 2 0.9 Male (%) 31 (62%) 69(58%) 0.8 Subtype of vascular ring: Double aortic arch RAA-ALSA Others 8 (16%) 42 (80 %) 0 (0 %) 90 (72%) 22 (17%) 8 (11%) 0.002 0.01 Associated intracardiac CHD: VSD TOF DORV AVSD Coarctation of aorta Others 11 (22%) 1 1 3 0 3 3 24 (20%) 5 7 2 2 3 5 0.8 Associated genetic diagnosis: 22q11 deletion Trisomy 21 Others 9 (18%) 6 3 0 32 (26%) 29 3 0 0.1 Symptomatic presentation: Respiratory Gastrointestinal 26 (52 %) 15 11 72 (60 %) 57 15 <0.03 Age at first symptoms (month) 3.2 ± 2.8 21.6 ± 37 0.01 Diagnostic modalities: Fetal echocardiogram Postnatal echocardiogram Barium swallow Bronchoscopy CT scan MRI 50 (100%) 50 (100%) 2 (4%) 3 (6%) 18 (36 %) 4 (8%) 0 (0%) 120 (100%) 23 (25 %) 18 (15 %) 65 (54%) 7 (14%) Surgical repair 28 (56%) 102 (85%) 0.02 Age at surgical repair (month) 12.6 ± 10.2 22.9 ± 35 <0.01 Postoperative complications 1 (3%) 8 (7%) 0.03 Residual symptoms 2 (1%) 30 (25%) 0.001 Age at most recent follow up (mo) 26 ± 7 60 ± 7 0.02 Table 1: Comparison of patients with prenatal versus postnatal diagnosis of vascular ring

Treatment of fetal circular shunt with non-steroidal anti-inflammatory drugs

A circular shunt (CS) is a life-threatening condition involving massive shunting of systemic arterial blood via the ductus arteriosus to the left ventricle without traversing the lungs. In the prenatal setting, it occurs mainly in fetuses with severe forms of Ebstein's anomaly (EA) owing to unrestricted ductal flow and significant pulmonary and tricuspid regurgitation. We aimed to improve the fetal hemodynamics and chances of survival of affected fetuses by inducing ductal constriction using transplacental non-steroidal anti-inflammatory drugs (NSAIDs). Following initiation of treatment between 26 and 34 weeks' gestation, three (75%) of four fetuses with EA/CS responded with sustained ductal constriction and improved hemodynamic function, which allowed continuation of pregnancy for 3-7 weeks and elective delivery. All successfully treated cases underwent neonatal surgery immediately after birth to eliminate the CS and survived. This included two neonates that underwent single-ventricle palliation surgery that required postoperative extracorporeal membrane oxygenation and hemofiltration for transient respiratory and renal failure. The one case that did not respond to treatment with NSAIDs was delivered prematurely for progressive fetal compromise and died shortly after birth. Transplacental treatment with NSAIDs represents a novel approach to controlling fetal CS, avoiding in-utero death and prolonging the pregnancy to a more advanced gestational age, thereby potentially increasing the chances of neonatal survival. This treatment should be considered and initiated at an early stage of systemic steal to prevent brain injury due to hypoperfusion. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Association between fetal growth, cerebral blood flow and neurodevelopmental outcome in univentricular fetuses

OBJECTIVE

To investigate the association of fetal growth and cerebrovascular resistance at different periods in gestation with neurodevelopment (ND) at 14 months in the univentricular subject.

METHODS

We reviewed serial prenatal ultrasound (US) examinations from 133 infants enrolled in the Pediatric Heart Network's Single Ventricle Reconstruction or Infants with Single Ventricle trials, including a subset of 82 infants in whom ND was assessed at 14 months using mental (MDI) and psychomotor (PDI) developmental indices. US examinations were assigned to one of four gestational time periods: (1) 20-23 weeks, (2) 24-29 weeks, (3) 30-33 weeks and (4) ≥ 34 weeks. Middle cerebral artery (MCA) flow velocity was measured and pulsatility index (PI), a measure of downstream resistance, was calculated. Data on fetal head circumference (HC), femur length, abdominal circumference (AC) and estimated fetal weight (EFW) were collected and their Z-scores were calculated. We evaluated the rate of change of these parameters over time within individuals, tested correlations between fetal growth and ND and assessed predictors of ND using linear regression.

RESULTS

The mean prenatal HC Z-score was < 0 at each gestational-age period and became more negative later in pregnancy. There was less growth in HC from time period 3 to period 4 compared with from period 2 to 3 (Δ HC Z-score, -0.07 ± 0.1 vs 0.11 ± 0.22, P = 0.03). Though ND did not correlate with HC, HC Z-score or MCA-PI Z-score, HC growth from period 2 to period 3 correlated with MDI (r = 0.45, P = 0.047). AC Z-score in period 4 predicted MDI (β = 4.02, P = 0.04). EFW Z-score and AC Z-score in period 2 predicted PDI (β = 10.6, P = 0.04 and β = 3.29, P = 0.047, respectively). Lower MCA-PI at initial US predicted higher PDI (β = -14.7, P = 0.03).

CONCLUSION

In univentricular fetuses, lower cerebrovascular resistance may be protective for ND. Decreased fetal somatic growth may predict developmental abnormalities. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Minimally invasive therapy for fetal sacrococcygeal teratoma: case series and systematic review of the literature

OBJECTIVE

Large solid sacrococcygeal teratomas (SCT) can cause high-output cardiac failure and fetal or neonatal death. The aim of this study was to describe the outcomes of minimally invasive antenatal procedures for the treatment of fetal SCT.

METHODS

A case review was performed of five fetuses with a large SCT treated antenatally using minimally invasive techniques, and a systematic literature review on fetal therapy for solid SCTs was carried out.

RESULTS

Five women were referred between 17 + 5 and 26 + 4 weeks' gestation for a large fetal SCT with evidence of fetal cardiac failure. Vascular flow to the tumors was interrupted by fetoscopic laser ablation (n = 1), radiofrequency ablation (RFA; n = 2) or interstitial laser ablation  ±  vascular coiling (n = 2). There were two intrauterine fetal deaths. The other three cases resulted in preterm labor within 10 days of surgery. One neonate died. Two survived without procedure-related complications but had long-term morbidity related to prematurity. The systematic literature review revealed 16 SCTs treated minimally invasively for (early) hydrops. Including our cases, six of 20 hydropic fetuses survived after minimally invasive therapy (30%). Survival after RFA or interstitial laser ablation was 45% (5/11). Of 12 fetuses treated for SCT without obvious hydrops and for which perinatal survival data were available, eight (67%) survived. Mean gestational age at delivery after minimally invasive therapy was 29.7 ± 4.0 weeks. Survival after open fetal surgery in hydropic fetuses was 6/11 (55%), with a mean gestational age at delivery of 29.8 ± 2.9 weeks.

CONCLUSIONS

Fetal therapy can potentially improve perinatal outcomes for hydropic fetuses with a solid SCT, but is often complicated by intrauterine death and preterm birth.

Minimally invasive fetal therapy for hydropic lung masses: three different approaches and review of the literature

OBJECTIVE

To report three different antenatal therapeutic approaches for fetal lung masses associated with hydrops.

METHODS

Three prospectively followed cases are described, and all 30 previously published minimally invasive cases of fetal therapy for hydropic lung masses are reviewed.

RESULTS

Three hydropic fetuses with large intrathoracic lung masses presented at 17, 25 and 21 weeks of gestation, respectively. An aortic feeding vessel was identified in each case and thus a bronchopulmonary sequestration (BPS) was suspected. Under ultrasound guidance, the feeding vessel was successfully occluded with interstitial laser (Case 1), radiofrequency ablation (RFA) (Case 2) and thrombogenic coil embolization (Case 3). Complete (Cases 1 and 2) or partial (Case 3) resolution of the lung mass and hydrops was observed. A healthy infant was born at term after laser therapy (Case 1), and the involved lung lobe was resected on day 2 of postnatal life. In Case 2, hydrops resolved completely following RFA, but an iatrogenic congenital diaphragmatic hernia and abdominal wall defect became apparent 4 weeks later. The neonate died from sepsis following spontaneous preterm labor at 33 weeks. In Case 3, despite technical success in complete vascular occlusion with coils, a stillbirth ensued 2 days after embolization.

CONCLUSIONS

The prognosis of large microcystic or echogenic fetal chest masses associated with hydrops is dismal. This has prompted attempts at treatment by open fetal surgery, with mixed results, high risk of premature labor and consequences for future pregnancies. We have demonstrated the possibility of improved outcome following ultrasound-guided laser ablation of the systemic arterial supply. Despite technical success, RFA and coil embolization led to procedure-related complications and need further evaluation.

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.

Prenatal diagnosis and outcome of absent pulmonary valve syndrome: contemporary single-center experience and review of the literature

OBJECTIVE

To review the anomaly spectrum of prenatally detected absent pulmonary valve syndrome (APVS) and the outcome after diagnosis. Previous fetal studies reported survival rates of ≤ 25% for patients with intended postnatal care.

METHODS

Clinical data and echocardiograms of 12 cases with a fetal diagnosis of APVS between 2000 and 2010 were analyzed in this retrospective single-center study. Collected parameters included: gestational age at referral, associated fetal abnormalities, cardiothoracic ratio, maximum diameters of pulmonary annulus and main and branch pulmonary arteries, ventricular dimensions and function as well as ventricular Doppler flows. Karyotyping included fluorescence in-situ hybridization (FISH) analysis for microdeletion 22q11.2.

RESULTS

Median gestational age at diagnosis was 24 weeks. Three subtypes of APVS were observed: (1) with tetralogy of Fallot (TOF) and no arterial duct (n = 10; 83%); (2) isolated, with a large arterial duct (n = 1; 8%); and (3) with tricuspid atresia, right ventricular dysplasia and a restricted duct (n = 1; 8%). The cardiothoracic ratio and pulmonary artery dimensions were increased in all cases. The karyotype was abnormal in 70% of fetuses with TOF and their mortality rate was significantly higher due to pregnancy termination (n = 3) or perinatal demise (n = 2) (hazard ratio, 5; 95% CI, 0.87-28.9; P = 0.015). Of seven live births with active postnatal care, six children (86%) were alive without residual respiratory symptoms at a median follow-up of 4.7 (range, 2.1-10.6) years.

CONCLUSION

Outcome after fetal diagnosis of APVS was significantly better in this study compared with those of previous fetal series, with a low mortality rate for actively managed patients.

Non-cardiac manifestations of neonatal lupus erythematosus

Neonatal lupus erythematosus (NLE) is characterized by the transplacental passage of maternal anti-Ro and/or anti-La antibodies and characteristic illnesses in the foetus/neonate. Most attention has focused on the most serious complication- cardiac involvement. This article will focus on non-cardiac involvement. Skin involvement (cutaneous NLE) is present in 15-25% of children with NLE. The rash of NLE tends to be photosensitive but may be present at birth or in non-sun exposed areas. It is most frequently seen around the eyes, not in the malar area, but also occurs in other parts of the body. The pathology resembles the rash of subacute cutaneous lupus erythematosus. Anti-Ro antibodies are present in >95% with the remaining mothers having anti-U1RNP antibodies only. Asymptomatic elevation of liver function tests, which may be associated with evidence of cholestasis, is seen in 10-25% of cases of NLE. Mild hepatomegaly and less commonly splenomegaly may be present. Liver involvement seen in isolation or associated with other features. The pathology resembles idiopathic neonatal giant cell hepatitis. Any haematological lineage, neutropenia and thrombocytopenia most commonly, may be affected by NLE. Haematological involvement is almost always asymptomatic. There are protean manifestations of neurologic involvement in NLE: hydrocephalus, non-specific white matter changes, calcification of the basal ganglia and a 'vasculopathy'. The most unusual feature of NLE is the radiographic finding of stippling of the epiphyses (chondrodysplasia punctata). Overall, non-cardiac involvement of NLE is more common than cardiac. The study of these manifestations may lead to new insight into how autoantibodies lead to disease.

Percutaneous ultrasound-guided stenting of the atrial septum in fetal sheep

OBJECTIVES

Hypoplastic left heart syndrome (HLHS) with a restricitive foramen ovale is associated with high mortality related to fetal left atrial hypertension. Fetal atrial balloon septoplasty has largely failed to achieve adequate decompression due to the small size of the holes produced. We attempted to produce larger atrial communications by stenting the atrial septum in fetal sheep using a minimally invasive technique.

METHODS

We used a percutaneous, ultrasound-guided transpulmonary or transhepatic approach to attempt deployment of coronary stents (2-5 mm in diameter and 13-23 mm in length) in the atrial septum primum of 10 normal fetal sheep.

RESULTS

Coronary stents were deployed in eight of the 10 fetal sheep (119-139 days' gestation). The transhepatic route was unsuccessful (n = 2). Transpulmonary implantation was only possible in prone fetuses, so three initially supine fetuses underwent external version. Small coronary stents (2.0-2.5 mm in diameter) were deployed rapidly without complication via an 18G needle (n = 4). Larger coronary stents (5 mm in diameter) were delivered through a 4F sheath, but a right pleural effusion occurred in three of the four cases, related to inferior vena cava injury by the balloon. One stent dislodged from a floppy septum. Another was partially occluded within a week by endocardial cells.

CONCLUSIONS

Percutaneous ultrasound-guided deployment of coronary stents into the septum primum is feasible without laparotomy or uterine exteriorization in fetal sheep. Partial luminal occlusion by rapid proliferation of endocardial cells is a concern.

Fetal sonographic diagnosis of aortic arch anomalies

Aortic arch anomalies refer to congenital abnormalities of the position or branching pattern, or both of the aortic arch. Although aortic arch anomalies are not uncommon, reports on their prenatal diagnosis are scarce. Insight into the hypothetical arch model is crucial to understanding anomalies of the aortic arch in the fetus. Recognition of the trachea, three major vessels, ductus arteriosus and descending aorta in the axial views of the upper mediastinum is necessary for a complete fetal cardiac assessment. Clues to aortic arch anomalies include abnormal position of the descending aorta, absence of the normal 'V'-shaped confluence of the ductal and aortic arches, a gap between the ascending aorta and main pulmonary artery in the three-vessel view, and an abnormal vessel behind the trachea with or without a vascular loop or ring around the trachea. Meticulous attention to anatomic landmarks will lead to successful prenatal diagnosis of important vascular rings making early postnatal management possible.

Electrocardiographic depolarization and repolarization: long-term after Kawasaki disease

To assess myocardial electric potentials late after Kawasaki disease (KD) we measured signal-averaged electrocardiography (SAECG) and QT dispersion parameters. Thirteen patients with persistent coronary aneurysm (group I), 12 with late resolution of the aneurysm (>3 months) (group II), and 13 with early resolution (group III) were studied 7.9 +/- 3.9, 6.7 +/- 3.9, and 7.2 +/- 3.6 years after the initial diagnosis (p = NS). In group I, myocardial infarction occurred in one patient during the acute illness, and coronary thrombosis in another; all except two patients had giant aneurysm (n = 8) and/or stenosis (n = 7). At 40-Hz high-pass filter SAECG, terminal 40-msec root mean square amplitude (RMS40) was significantly lower in group I versus II and III (64.1 +/- 40.8 microV, 79.9 +/- 47.2 microV, and 115 +/- 65.4 microV, respectively; p <0.05). Global QT dispersion was significantly greater in group I versus III (52 +/- 11 msec and 37 +/- 11 msec, respectively; p <0.05), but not in comparison to group II (45 +/- 13 msec). The same trend was present for rate-corrected QT dispersion, without reaching statistical significance (84.0 +/- 34, 71.5 +/- 31, and 61.8 +/- 21 respectively). Both depolarization and repolarization parameters are altered in patients with persistent coronary artery aneurysms long-term after KD. This may represent risk factors for developing ventricular arrhythmia in a growing population.

Inhaled nitric oxide versus aerosolized iloprost in secondary pulmonary hypertension in children with congenital heart disease: vasodilator capacity and cellular mechanisms

BACKGROUND

Inhaled nitric oxide (iNO) has been used to assess the vasodilator capacity of the pulmonary vascular bed in children with congenital heart disease and elevated pulmonary vascular resistance. Inhaled iloprost is a pulmonary vasodilator for the long-term treatment of pulmonary hypertension (PHT). Because these 2 vasodilators act through different pathways (release of cGMP or cAMP, respectively), we compared the pulmonary vasodilator capacity of each.

METHODS AND RESULTS

A total of 15 children with congenital heart disease and PHT who had elevated pulmonary vascular resistance (preoperative, n=10; immediately postoperative, n=5) were first given 20 ppm of iNO for 10 minutes; then, after baseline values were reached again, they were given aerosolized iloprost at 25 ng. kg(-1). min(-1) for another 10 minutes. Finally, iNO and iloprost were given simultaneously for 10 minutes. With iNO, the pulmonary vascular resistance and systemic vascular resistance ratio decreased from 0.48+/-0.38 to 0.27+/-0.16 (P:<0.001). Similarly, iloprost decreased the ratio from 0.49+/-0.38 to 0.26+/-0.11 (P:<0.05). The combination had no additional effect on the resistance ratio. Plasma cGMP increased from 17.6+/-11.9 to 34.7+/-21.4 nmol/L during iNO (P:<0.01), and plasma cAMP increased from 55.7+/-22.9 to 65.1+/-21.2 nmol/L during iloprost inhalation (P:<0.05).

CONCLUSIONS

In children with PHT and congenital heart disease, both iNO and aerosolized iloprost are equally effective in selectively lowering pulmonary vascular resistance through an increase in cGMP or cAMP, respectively. However, the combination of both vasodilators failed to prove more potent than either substance alone. Aerosolized iloprost might be an alternative to iNO for early testing of vascular reactivity and for the postoperative treatment of acute PHT.

Treatment of supraventricular tachycardias in the new millennium--drugs or radiofrequency catheter ablation?

Supraventricular tachycardias are a cause of significant morbidity in children. Newer anti-arrhythmic drugs and the invention of radiofrequency catheter ablation have revolutionised anti-arrhythmic therapy in children.

CONCLUSION

With the availability of these very effective therapeutic options, an improved knowledge of these methods and their indications is required.

Role of ischemia and infarction in late right ventricular dysfunction after atrial repair of transposition of the great arteries

OBJECTIVES

This study was conducted to assess whether myocardial ischemia and/or infarction are involved in the pathogenesis of late right ventricular dysfunction in adult survivors of atrial baffle repair for transposition of the great arteries in infancy.

BACKGROUND

The medium-term success of intraatrial baffle repair for transposition of the great arteries is good, with many patients surviving into adult life, but prognosis can be limited by progressive right ventricular dysfunction. We hypothesized that ongoing myocardial ischemia and/or infarction are important factors in the pathogenesis of this complication. Radionuclide techniques offer an opportunity to study both myocardial perfusion and concomitant ventricular wall motion.

METHODS

Dipyridamole sestamibi single-photon emission computed tomography followed by rest sestamibi single-photon emission computed tomography was used to assess right ventricular myocardial perfusion, wall motion, wall thickening and ejection fraction in 22 adolescents/young adults who had undergone atrial baffle repair for simple transposition of the great arteries at median 6.7 (range 0.5 to 54) months of age. The patients were aged 10 to 25 (median 15.5) years; 19 in New York Heart Association class I, 2 in class II and 1 in class III. All were in a regular cardiac rhythm during the studies. The right ventricular tomographic images were examined in three parallel and two orthogonal planes, analyzed in 12 segments.

RESULTS

Perfusion defects were evident in all patients in at least one segment, in either the rest or stress images. Twelve patients (55%) demonstrated fixed defects only, nine (41%) had fixed and reversible defects and one (4.5%) had reversible defects only. Concomitant wall-thickening abnormalities occurred in 83% of segments with fixed perfusion defects, mirrored by a reduction in wall motion in 91% of segments analyzed. Right ventricular ejection fraction was correlated with age (R = 0.62; p = 0.002), and with wall-thickening abnormalities (R = 0.60; p < 0.005).

CONCLUSIONS

Reversible and fixed perfusion defects with concordant regional wall motion abnormalities occur in the right (systemic) ventricle 10 to 20 years after Mustard repair for transposition of the great arteries; this may be important in the pathogenesis of late right ventricular dysfunction in this group.

Anterior mitral leaflet prolapse as a primary cause of pure rheumatic mitral insufficiency

BACKGROUND

This study was designed to revise the mechanisms and repair techniques of anterior mitral leaflet prolapse observed during the correction of pure rheumatic mitral regurgitation in children.

METHODS

From March 1993 to May 1998, 36 children suffering from pure rheumatic mitral regurgitation due to anterior leaflet prolapse underwent mitral valve repair. The mean age was 12.5 years (range, 6 to 16 years). Anterior leaflet prolapse was due to chordal elongation in 25 patients (group A), chordal rupture in 6 patients (group B), and retraction of anterior secondary chordae tendineae, creating a V-shaped deformity in the middle of the anterior leaflet, thus moving the free edge of the anterior leaflet away from the coaptation plane, in 5 patients (group C). Chordal shortening, transposition, and resection of anterior secondary chordae tendineae were used to correct anterior leaflet prolapse according to the predominantly responsible mechanism.

RESULTS

All patients were available for clinical follow-up, which ranged from 6 months to 5 years (mean follow-up, 3 years). Echocardiographic studies were obtained until the 3rd postoperative month, and all patients showed significant improvement in their left ventricular and atrial dimensions. There was one late death related to endocarditis. Two patients in group C who had mitral valve repair underwent mitral valve replacement on the 19th and 24th postoperative months, respectively, because of failure of mitral valve repair.

CONCLUSIONS

Mitral valve repair for pure mitral regurgitation due to rheumatic anterior leaflet prolapse can be performed safely for all types of mechanisms. Although the techniques we used provide stable short-term results in each of these groups, midterm results are better in groups A and B, where tissue thickening is less important, recurrences of rheumatic carditis are lower, and the interval between the first rheumatic attack and the surgical procedure is shorter than in group C.

Right ventricular dysfunction in congenitally corrected transposition of the great arteries

Although right ventricular (RV) dysfunction is an important complication in subjects with congenitally corrected transposition of the great arteries, its pathogenesis is poorly understood. We assessed the role of RV myocardial perfusion and found perfusion defects at rest in all 20 patients, involving 4.6 +/- 2.3 of a total of 12 segments; the extent of the resting perfusion defects correlated inversely with the RV ejection fraction.

Successful radiofrequency ablation in an infant with drug-resistant permanent junctional reciprocating tachycardia

Over the past decade, the technique of radiofrequency ablation has evolved substantially. Currently, most forms of cardiac arrhythmias seen in children can be treated with good long-term results and low risk of adverse outcome. Curative arrhythmia treatment with this technique, however, is still uncommon in neonates and infants. Reported here is our experience in the management of an 8-week-old with drug-resistant permanent junctional reciprocating tachycardia.

Relationship between flow through the fetal aortic isthmus and cerebral oxygenation during acute placental circulatory insufficiency in ovine fetuses

OBJECTIVE

We sought to investigate whether the reversal of blood flow through the aortic isthmus, as observed during an increase in placental vascular resistance, could be responsible for a significant fall in oxygen delivered to the fetal brain.

STUDY DESIGN

With the appearance of reverse flow in the aortic isthmus, preplacental blood with low oxygen saturation could contaminate the ascending aorta blood destined for the brain. Stepwise compression of the umbilical veins of 8 exteriorized fetal lambs was realized at approximately 140 days of gestation. Four other animals were used as controls. Flows through the aortic isthmus and both carotid and umbilical arteries were measured by Doppler echocardiography in the basal state (hemodynamic class 1) and during moderate (class 2), severe (class 3), and extreme (class 4) increases in resistance to placental flow. Oxygen delivered to the brain was calculated from carotid blood flow and oxygen content.

RESULTS

In the control group no change was noted in umbilical and carotid arteries or in the aortic isthmus blood flow. Oxygen delivered to the brain remained stable. In the study group the increase in resistance to placental flow caused a significant fall in umbilical flow and carotid oxygen content, while blood flow in the carotid arteries increased slightly. The values for aortic isthmus flow and oxygen delivered to the brain during the 4 hemodynamic classes were, on average, as follows: class 1, 98.2 and 2.9 mL/(min x kg); class 2, 52.8 and 3.1 mL/(min x kg); class 3, 3.7 and 2.6 mL/(min x kg); and class 4, -29.8 and 0.7 mL/(min x kg), respectively.

CONCLUSION

During an acute increase in placental vascular resistance, delivery of oxygen to the brain is preserved despite a significant drop in arterial oxygen content as long as net flow through the isthmus is anterograde.

Adenosine-induced atrial pro-arrhythmia in children

Adenosine has become the preferred acute treatment for common types of supraventricular tachycardia because of its efficacy and safety. There have been a few reports of serious proarrhythmic events associated with its use, including the induction of atrial fibrillation in adult patients. Three instances of adenosine-induced atrial proarrhythmia (two atrial fibrillation and one atrial flutter) have been observed in children with manifest or concealed Wolff-Parkinson-White syndrome at the Hospital for Sick Children, Toronto, Ontario since 1990, which indicates a previously unreported risk of atrial arrhythmia for children as well. Because adenosine may enhance antegrade bypass tract conduction, its use carries a risk of ventricular acceleration, including progression to ventricular fibrillation. Because of such rare and potentially life-threatening adverse effects, appropriate monitoring and precautions are required during the administration of the drug to children and adults.

Segmental myocardial contractility versus perfusion in Kawasaki disease with coronary arterial aneurysm

The impact of Kawasaki-related coronary injury on the myocardium was evaluated in 13 patients with persistent coronary aneurysm after a follow-up period of 7.92+/-3.97 years (range 1.8 to 14.3). Myocardial segmental perfusion and contractility integrity were assessed by resting and exercise echocardiography and technetium-99 (Tc-99m) sestamibi scan. Eight patients (61.5%) had giant aneurysms (> or = 8 mm) and 9 had multivessel involvement; the mean diameter of the largest aneurysm was 8.6+/-2.5 mm (range 5 to 14). During the acute phase, myocardial infarction occurred in 1 patient and coronary thrombosis in another. At the latest echocardiographic evaluation, the mean aneurysm diameter was 6.8+/-2.4 mm (range 4.5 to 12), there was persistent giant aneurysms in 5 of 8 patients, and 3 of 9 patients had multivessel involvement. Coronary angiography demonstrated stenosis in 7 of 10 patients, with multiple levels in 2. At sestamibi scan, all 13 patients had perfusion anomalies at rest, whereas only 7 had detectable hypokinesia on echocardiography. With exercise, perfusion returned to near normal in 3 patients, improved in 3, remained unchanged in 4, and worsened in 3 patients. Segmental contractility similarly deteriorated in the latter 3 patients but also in 2 patients whose perfusion scan had improved with exercise. Three patients, normal at rest, developed segmental hypokinesia during exercise. When present, the location of observed changes in contractility on stress echocardiography corresponded to that of perfusion defect. In conclusion, abnormal myocardial perfusion is present long term after complicated Kawasaki disease, the worst anomalies accompanying persistent giant aneurysms. Unfavorable perfusion response was coupled with abnormal contractility; however, enhanced perfusion with exercise correlated poorly with segmental contractility response.

Ventriculo-atrial time interval measured on M mode echocardiography: a determining element in diagnosis, treatment, and prognosis of fetal supraventricular tachycardia

OBJECTIVE

To determine whether M mode echocardiography can differentiate fetal supraventricular tachycardia according to the ventriculo-atrial (VA) time interval, and if the resulting division into short and long VA intervals holds any relation with clinical presentation, management, and fetal outcome.

DESIGN

Retrospective case series.

SUBJECTS

23 fetuses with supraventricular tachycardia.

MAIN OUTCOME MEASURES

A systematic review of the M mode echocardiograms (for VA and atrioventricular (AV) interval measurements), clinical profile, and final outcome.

RESULTS

19 fetuses (82.6%) had supraventricular tachycardia of the short VA type (mean (SD) VA/AV ratio 0.34 (0.16); heart rate 231 (29) beats/min). Tachycardia was sustained in six and intermittent in 13. Hydrops was present in three (15.7%). Digoxin, the first drug given in 14, failed to control tachycardia in five. Three of these then received sotalol and converted to sinus rhythm. All fetuses of this group survived. Postnatally, supraventricular tachycardia recurred in three, two having Wolff-Parkinson-White syndrome. Four fetuses (17.4%) had long VA tachycardia (VA/AV ratio 3.89 (0.82); heart rate 226 (10) beats/min). Initial treatment with digoxin was ineffective in all, but sotalol was effective in two. Heart failure caused fetal death in one and premature delivery in one. All three surviving fetuses had recurrences of supraventricular tachycardia after birth: two had the permanent form of junctional reciprocating tachycardia and one had atrial ectopic tachycardia.

CONCLUSIONS

Careful measurement of ventriculo-atrial intervals on fetal M mode echocardiography can be used to distinguish short from long VA supraventricular tachycardia and may be helpful in optimising management. Digoxin, when indicated, may remain the drug of choice in the short VA type but appears ineffective in the long VA type.

Foetal supraventricular tachycardia treated with sotalol

This retrospective study (1991-95) presents our experience with sotalol in the treatment of 14 foetuses with supraventricular tachycardia (SVT). SVT was diagnosed in a structurally normal heart at a gestational age of 24-35 (median 28) weeks. In eight foetuses, hydrops was evident at presentation. In all patients pharmacological conversion with digoxin was tried before sotalol treatment was started. Sotalol was given orally to the mothers in a dose of 80-160 mg x 2. Cardioversion was obtained in 10 foetuses. In seven of these patients re-entry tachycardia and in five pre-excitation could be documented after birth. In two foetuses not responding to sotalol a long RP tachycardia was demonstrated; even when using digoxin, sotalol, flecainide and/or propafenone in different combinations after birth complete suppression of the arrhythmia was not obtained. Two severely hydropic foetuses died 1 and 10 d, respectively, after starting with sotalol. The 12 surviving infants were doing well except for one infant, with a cerebral lesion probably related to the arrhythmia. These findings demonstrate that sotalol can be useful in the treatment of foetal SVT.

Reversible second degree atrioventricular block after a severe sickle cell crisis

Despite the high prevalence of sickle cell disease and trait in the black population and its serious potential for microinfarction, there are only a few reports on acute myocardial damage during vasoocclusive crisis. We report a unique case of transient second degree atrioventricular (A-V) block of Mobitz I and II type during a severe sickle cell crisis. Localized high ventricular septum hypoperfusion demonstrated by a 99mTc-MIBI radionuclide study and reversible echocardiographic wall motion abnormalities in the same area were strong indicators for a local ischemic event in the A-V node and His bundle area, explaining the observed transient conduction abnormalities. The present report draws attention to a potentially lethal complication of sickle cell crisis.

Fetal atrial flutter: diagnosis, clinical features, treatment, and outcome

OBJECTIVES

To assess clinical features, treatment efficacy, and outcome of fetal atrial flutter.

STUDY DESIGN

All atrial flutter cases seen in our unit between 1988 and 1995 were reviewed retrospectively and compared with the pooled data of 37 echocardiographically documented and published cases.

RESULTS

Atrial flutter was found in 15 of 49 (30.6%) fetuses who had been referred because of clinically relevant tachyarrhythmia. Mean age at detection was 34+/-4 weeks' gestation. Atrial flutter was incessant in 11 and intermittent in 4, with a mean atrial rate of 442+/-65 beats/min and a mean ventricular rate of 216+/-28 beats/min. A predominance of 2:1 atrioventricular conduction was observed. In 5 of 15 cases another form of arrhythmia (supraventricular tachycardia, chaotic atrial rhythm, ventricular extrasystoles) coexisted with atrial flutter. Eleven fetuses were treated with maternal digoxin, and five subsequently converted to sinus rhythm. Four fetuses received no medication; of these four, two showed brief self-limited episodes of atrial flutter and two were delivered after detection of the arrhythmia. Only one fetus (6.7%), who did not respond to drug therapy, was delivered prematurely because of mild congestive heart failure. Seven neonates were in atrial flutter at birth; rhythm control could be easily achieved with sotalol or digoxin (n = 5), flecainide (n = 1), or electroconversion (n = 1) within the first 2 days of life without any relapse.

CONCLUSION

Fetal atrial flutter accounts for approximately one third of all clinically relevant tachyarrhythmia. Although the suppression rate of incessant atrial flutter with digoxin is only 50%, this therapy may be useful for its positive inotropic and negative chronotropic properties. In our experience most fetuses with therapy-resistant atrial flutter and absence of 1:1 atrioventricular conduction do not experience congestive heart failure and do not need to be delivered prematurely. After birth, conversion to sinus rhythm was easily achieved in all neonates.

Successful weaning from cardiopulmonary bypass after cardiac surgery using inhaled nitric oxide

Two cases of very difficult weaning from cardiopulmonary bypass after cardiac surgery in children with pulmonary hypertension and ventricular dysfunction are reported. Children fail to respond to conventional therapy combining nitrovasodilators and inotropic support and react successfully to combined inhaled nitric oxide (NO) and epinephrine or left atrial infused norepinephrine. Postoperative NO inhalation must be prolonged and no toxicity appears. Pulmonary endothelial function recovers only after several days.

Congenital scalp and skull defects with terminal transverse limb anomalies (Adams-Oliver syndrome): report of three additional cases

Aplasia cutis congenita of the scalp combined with terminal transverse limb defects (Adams-Oliver syndrome) is a rare congenital disorder with autosomal dominant inheritance. Thirty-one patients with the complete syndrome have been published. We report three additional patients (one mother and her affected child, one sporadic case) and discuss the probable vascular disruptive pathogenesis, the clinical variability and the treatment of this condition in the light of a comprehensive review of the literature.

Warning symptoms of hypoglycaemia during treatment with human and porcine insulin in diabetes mellitus

32 subjects with long-term insulin-dependent diabetes mellitus (IDDM) were entered into a double-blind, randomised crossover trial with human and porcine insulin. They were treated during both periods with regular insulin and with protamine (NPH) insulin. 18 subjects started with human and 14 with porcine insulin; the two insulin periods each lasted twelve weeks; the insulin doses were much the same in the two periods (mean 23 [SD 9] U daily NPH; 14 [7] U daily regular insulin), as were blood glucose profiles and HbA1c values. There were 171 episodes of hypoglycaemia during human and 150 episodes during porcine insulin. Patients completed questionnaires after each hypoglycaemic episodes and at the end of the trial. Hunger and sweating without concomitant neuroglycopenic symptoms were significantly more frequent as initial warning symptoms during porcine than during human insulin (41% vs 20%), whereas neuroglycopenic symptoms were more frequent during human insulin. At the end of the trial 18 of 32 subjects reported diminished awareness of hypoglycaemia during human insulin compared with 6 of 32 during porcine insulin. Hypoglycaemia developed faster during human than during porcine insulin administration. The transfer of IDDM subjects from porcine to human insulin seems to alter warning symptoms of low blood glucose concentration, with consequent impairment of its early recognition.