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.

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.

Influence of perioperative factors on outcomes in children younger than 18 months after repair of tetralogy of Fallot

BACKGROUND

There has been a trend toward advocating earlier repair of tetralogy of Fallot and avoiding palliative procedures. The impact of this trend on perioperative outcomes has not been adequately documented.

METHODS

Data from consecutive patients undergoing repair of tetralogy of Fallot at less than 18 months of age from May 1987 to September 1994 were reviewed. Independent factors associated with duration of stay in the intensive care unit were sought.

RESULTS

Repair was performed in 89 infants at a median age of 13 months (range, 15 days to 18 months). A systemic-pulmonary artery shunt was present in 24% of patients. Mean duration of cardiopulmonary bypass was 119+/-37 minutes; 63% of patients received a transannular patch. There were six deaths (7%), all occurring less than 48 hours after repair. The median duration of stay in the intensive care unit was 5 days (range, 1 day to 8 months). Significant independent factors associated with increasing length of intensive care unit stay included younger age at repair, previous shunt, malformation syndrome, increased total dose and number of inotropic agents used, and respiratory complications. Hemodynamic variables serially recorded in the first 48 hours after repair were independently associated with death or prolonged (>7 days) duration of stay.

CONCLUSIONS

Although outcomes after repair of tetralogy of Fallot in infants are good, both younger age at repair and previous palliative procedures were associated with longer duration of stay in the intensive care unit.

Obstructive rhabdomyoma and univentricular physiology: a rare combination

We report the successful excision of a large left atrial rhabdomyoma producing complete obstruction of both inflow and outflow to the left ventricle. Systemic perfusion was dependent on anterograde ductual flow. The resultant univentricular physiology was initially managed medically, with spontaneous tumor regression contemplated as a means of possible long-term "cure." Failure to achieve hemodynamic stability compelled urgent surgical excision. This neonate was successfully discharged home with an in-series biventricular circulation.

Total one-stage repair of aortopulmonary window and interrupted aortic arch in a neonate

The congenital anomaly of aortopulmonary window is rare. Its combination with interruption of the aortic arch has been previously recognized and reported in infants and children. Early and complete repair of such a congenital anomaly may prevent progression to cardiac failure and premature death. We describe the successful echocardiographic diagnosis and one-stage surgical repair, via a median sternotomy, of the aortopulmonary window, interrupted aortic arch, patent ductus arteriosus, and patent foramen ovale in a 3-day-old neonate. The literature is also reviewed.

Adrenoceptor-stimulated endothelium-dependent relaxation in porcine intrapulmonary arteries

The responses of rings of isolated adult porcine intrapulmonary arteries to noradrenaline were observed. The effects of prazosin (alpha-1 adrenoceptor antagonist), yohimbine (alpha-2 adrenoceptor agonist) and N-omega-nitro-L-arginine methyl ester (L-NAME) on the noradrenaline responses were studied. In addition, following contraction with prostaglandin PGF2 alpha, the responses to noradrenaline or UK 14304 (alpha-2 adrenoceptor agonist) were observed alone and in the presence of either prazosin or yohimbine. The effects of UK14304 were also observed following precontraction with phenylephrine. Noradrenaline produced an initial increase in vascular tone followed by a decrease and then a second increase in tone at high concentrations. The initial contractile response was inhibited by prazosin or yohimbine. L-NAME or endothelium removal enhanced the contractile responses and abolished the mid range reduction in tone. Following PGF2 alpha pre-contraction, UK14304 further increased the tone, with a reduction in tone at higher concentrations. the contractile effect was augmented by prazosin. Following phenylephrine pre-contraction, UK14304 only produced reduction in tone. In conclusion, in porcine intrapulmonary arteries, L-NAME inhibited noradrenaline induced endothelium dependent reduction in tone, which was also inhibited by alpha-1 and alpha-2 antagonists. UK14304 demonstrated partial alpha-1 agonism.

Severe unconjugated hyperbilirubinaemia with infradiaphragmatic total anomalous pulmonary venous connection

An 8 day old girl with infradiaphragmatic total anomalous pulmonary venous connection presented with severe unconjugated hyperbilirubinaemia; exchange transfusion resulted in haemodynamic deterioration. Hyperbilirubinaemia is a rare complication of this condition, however exchange transfusion should be avoided. The diagnosis can be made on the neonatal unit by ultrasound demonstration of dilated hepatic portal veins.