Early prenatal diagnosis of endocardial fibroelastosis

Abstract

Endocardial fibroelastosis is characterized by a diffuse thickening of the ventricular endocardium1, and usually leads to death from congestive heart failure in early infancy. It can be secondary to congenital heart malformations such as aortic stenosis or atresia, aortic coarctation, anomalous coronary arteries and ventricular septal defect2. Several factors may explain primary fibroelastosis2-4, including intrauterine viral myocarditis (mumps, coxsackie virus B)3, autoimmune processes (antibody deposition throughout the myocardium after passive transplacental passage of maternal anti-Ro/anti-La antibodies4, which induces inflammation and fibrosis in the developing myocardium), subendocardial ischemia, impaired lymphatic drainage of the heart, systemic carnitine deficiency, and mucopolysaccharidosis. In the 1960s, the incidence of endocardial fibroelastosis was 1 in 5000 live births2, 5 but it has dramatically decreased in occurrence since the use of the measles-mumps-rubella vaccination. Recurrence in subsequent pregnancies is estimated at 3–5%2. Although the disease is sporadic, 10% of cases are familial with various genetic mutations. A 32-year-old woman (gravida 2, para 1) underwent routine ultrasound examination at 12.5 weeks' gestation, which revealed a hypokinetic cardiac left ventricle with wall thickening (Figure 1). Two weeks later, hypokinesis was confirmed and was found to be associated with a hyperechogenic septum, aortic atresia and mitral stenosis. The pulmonary artery was the only visible vessel. Endocardial fibroelastosis was suspected and, following counseling, termination was performed at 15 weeks' gestation with intravaginal prostaglandin. Four-chamber view showing the left ventricle (LV) with a thickened wall at 12.5 weeks. (a) Ventricular diastole. (b) Ventricular systole. (c) Color Doppler imaging during ventricular diastole showing filling of the right ventricle (RV), but no flow in the left ventricle. On pathological examination, the fetus weighed 68 g and was 14 cm in length. Conclusive dissection of the four valves of the heart, which was 12 × 8 mm and weighed less than 1 g, was not possible. Macroscopically, the left ventricle presented with concentric hypertrophy with a thickened wall (2–3 mm) (Figure 2). The left atrium was hypoplastic. Histological examination showed a fibrous thickening of the endocardium with collagenous bands admixed between myocytes, which confirmed the diagnosis. The interventricular wall was thickened with microcalcifications. Macroscopic sections of the heart. Concentric hypertrophy of the left ventricle with a thickened wall (2–3 mm) and interventricular septum. Hypoplastic left atrium (original measurement 3 × 4 mm) compared to the right atrium (original measurement 7 × 9 mm). Primary and secondary endocardial fibroelastosis seem to follow the same pathophysiology2. The endocardial thickening results from ventricular hypokinesis secondary to a damaged myocardium. This chronic myocardial stress results in the production of collagen and elastin with fibroelastic thickening of the endocardium, which leads to myocardial dysfunction. In the literature, endocardial fibroelastosis has generally been reported in young children or in second- and third-trimester fetuses. However, the condition is likely to develop earlier in pregnancy, as we have shown, and as was also demonstrated by Rustico et al.5 who reported a case of endocardial fibroelastosis with aortic stenosis at 14.5 weeks' gestation. Our observation stresses the importance of first-trimester ultrasound examination, which can allow early termination for lethal diseases. Nevertheless, the benefits of such early systematic screening for heart diseases have to be weighed against the negative aspects6. When severe abnormalities are noticed so early it is likely that spontaneous miscarriage will ensue and parents should have the choice of continuing the pregnancy until it reaches its natural end. C. Trastour*, A. Bafghi*, J. Delotte*, C. Mainguene , B. Benoit*, A. Bongain*, * Department of Gynecology-Obstetrics-Infertility Fetal Medicine, Prenatal Diagnosis Unit, Archet II Hospital, 151 route St-Antoine de Ginestière BP 3079, 06202 cedex 3 Nice, France, Department of Pathology, Princess Grace Hospital, Monaco