Fetal autoimmune myocarditis and complete heart block – a case report

Introduction

Myocarditis in a fetus is a rare disease, and there are no large studies that establish its clear pathomechanisms. It is a disease with an extremely wide range of clinical presentations, from asymptomatic to life-threatening, importantly including sudden death [1-4]. 

Case study

The patient was referred for a fetal echocardiographic examination at 25.3 weeks of pregnancy due to bradycardia of 55 bpm. Third-degree atrioventricular block was diagnosed, and treatment with hydroxychloroquine and steroids (at a daily dose of 200 mg, and dexamethasone – initially at a dose of 4 mg/day orally then intravenously 3 × 4 mg, and betamethasone – 2 × 12 mg intramuscularly), as an anti-inflammatory and immunosuppressive therapy due to confirmation of the presence of antinuclear Ro-52 and Ro-60 maternal antibodies, was initiated (Table 1). So far, the patient has not been chronically ill; it is her first pregnancy. Echocardiography revealed the following: cardiomegaly – cardiothoracic ratio 0.5 and cardio-vascular profile score 8. Mild mitral and mild-to-moderate tricuspid regurgitation [5] were also seen (Figure 1), with correct ventricular contractility, correct width, and right-to-left foramen ovale valve opening, in which the peak systolic foramen ovale flow was 40 cm/s. The occurrence of disseminated focal areas of myocarditis was confirmed: scattered echogenic spots within the left ventricle, right ventricle, interventricular septum, and non-contiguous echogenic patches throughout the tricuspid valve, mitral valve, left atrium, right atrium and hyperechogenic bowels, and oligohydramnios, with an amniotic fluid index of 6.4 cm (Table 1). The next examination took place after about two weeks (at 26.6 weeks). The patient was diagnosed with a decrease in cardiomegaly – the cardiothoracic ratio was 4, a discrete increase in pericardial fluid (3.5 mm) was observed, as well as the appearance of trace pulmonary regurgitation, and the cardio-vascular profile score was 7. An improvement in the amount of amniotic fluid was also obtained; the amniotic fluid index was 13 cm. Additional antibiotic therapy was proposed: biofuroxime, intravenous injections with dexamethasone, intramuscular betamethasone, and therapeutic plasmapheresis (in total, four plasmapheresis cycles were performed). During prenatal steroid therapy, significantly higher flow velocities through the fetal pulmonary veins were observed, with a peak systolic flow of 70 cm/s and a two-way nature of the flow through the foramen ovale opening. The patient received continuous rheumatological-cardiological-obstetric surveillance during pregnancy, and it was possible to start treatment with salbutamol due to the absence of cardiac contraindications (Table 1). In 28.5 weeks, improvement in the pulmonary valve regurgitation was achieved after antibiotic therapy. The growth of the fetus was observed within the normal range up to 33.4 weeks, and then we observed a slowdown in the growth of the fetus. The amount of amniotic fluid index also gradually decreased to 7 cm and the cardiothoracic ratio progressively improved/decreased to 0.3, although we observed an increase in pericardial effusion of 4 mm, and abnormalities in peripheral/extracardiac flows appeared: a significant increase in umbilical pulsatility index (to 3.16) and ductus venous reversal flow, but still with a cardio-vascular profile score of 8 with no cardiac failure obtained. During echocardiographic monitoring, the fetus had a constant tendency for nuchal cord while maintaining the same fetal position (Table 1). Myocarditis evolved to form the following: non-contiguous echogenic patches in the mitral valve, tricuspid valve, left atrium, and right atrium, as well as atrial and right ventricular enlargement and right ventricle hypertrophy (Figure 2, Table 2). The planned subsequent echocardiography at an interval of two weeks was not performed due to life-threatening symptoms in the fetus, and therefore the patient gave birth prematurely by Caesarean section at 36 weeks of pregnancy. A daughter was born with weight 2120 g, Ap 10/10, pH 7.31, base excess 1.3, normal oxygen saturation (98%), and elevated cardiac markers: B-type natriuretic peptide 950 pg/ml and troponin 453 ng/ml. Using a central venous access device, dopamine, and fraxiparin, steroid therapy was initiated shortly after birth with a weight-adjusted dose, due to the confirmation of third-grade atrioventricular block with heart rate 60 bpm, positive for Ro-52 antibodies with a titre of 1 : 320. The feeding was completely parenteral. On the first day of life, two pericardial electrodes were implanted for external stimulation, obtaining effective stimulation with a heart rate of 130 bpm. On the sixth day of life, right pleural emphysema was observed, drainage of the pleural cavity was carried out, and in the following days there were difficulties in healing the wound after the drainage and growing CRP, with positive stool culture of Salmonella, Shigella, E. coli, Yersinia, and Campylobacter. Antibiotic therapy with amoxicillin and vancomycin was used. On day 17, normocytic anaemia led to the implementation of erythropoietin treatment and transfusion of a 0 Rh D blood product. On day 29, due to increasing stimulation disorders, after initially switching to a reserve electrode, it was finally decided that pacemaker implantation was urgently required. The hospitalization lasted a total of 7 weeks (including the prenatal period), and the child, in a generally good condition, was transferred to a cardiology clinic for further care.

Discussion

In the presented case, the heterogeneous echogenicity and variability of this image made us suspect myocarditis. Murlewska et al. [7] collected very important data about management in maternal autoantibody-mediated clinical fetal myocardial disease. Due to the increased risk of pregnancy complications among women with connective tissue disease, early assessment and detailed counselling should be implemented. If there is suspicion of any fetal myocardial disease, the authors point to the importance of the role of echocardiography. Furthermore, this examination is also an indicator of the degree of cardiac failure that should be taken into consideration during obstetric management. Fetal echo examination is indicated weekly from 16 weeks of gestation upwards in cases of involvement of positive maternal anti-Ro/SSA or anti-La/SSB antibodies. The authors quote one study that suggests that hydroxychloroquine could be used in the prevention of neonatal cardiac involvement in pregnant women who have had a fetal myocardial disease in a previous pregnancy [7].

Conflict of interest

The authors declare no conflict of interest.

References