Fetal bradyarrhythmias: classification, monitoring and outcomes of 40 cases at a single center

OBJECTIVES

To assess congenital fetal bradyarrhythmias with regard to etiological causes, features, risk factors, and prognosis.

METHODS

This retrospective study involved fetuses with fetal bradyarrhythmias. All fetuses were evaluated by ultrasonography. Parental ECGs and family histories were obtained, and maternal autoantibodies were measured. Gestational age at diagnosis, fetal atrial and ventricular rates at presentation, type of bradyarrhythmias, the presence or absence of a congenital heart defect (CHD), fetal hydrops, fetal myocardial dysfunction, extra-cardiac abnormalities, maternal autoimmune diseases, maternal autoantibodies as well as prenatal treatment, and neonatal outcome were collected.

RESULTS

Of the 40 fetuses included in the study, 11 had maternal rheumatologic disease, 16 had complex cardiac anomalies such as left and right isomerism. Fetuses with CHD significantly differed from those without CHD with increased rates of extra-cardiac anomalies, hydrops, fetal deaths and shorter survival after 28 days (p<0.05). Survival was significantly better in fetuses with maternal rheumatic disease as compared with those with no maternal rheumatic disease (p<0.05). Maternal anti-arrhythmic therapy was administered in 11 fetuses. In utero maternal treatment resulted in no significant difference in the course of arrhythmia or hydrops in fetuses with or without maternal rheumatic disease (p<0.05). In regression analysis, the absence of fetal hydrops was the only independent factor associated with survival (p=0.04).

CONCLUSIONS

The course of bradyarrhythmias, along with survival, seems to be more favorable in fetuses with maternal rheumatic disease than in those with CHD, especially left and right isomerism. Hydrops was the sole independent factor associated with poor survival.

Rapid Regression of Prenatally Identified Intrapericardial Giant Rhabdomyomas with Sirolimus

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Giant cardiac rhabdomyomas were identified on fetal echocardiography.

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The rhabdomyomas were unusually located in the pericardial space.

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Rapid regression and hemodynamic improvement were seen with sirolimus therapy.

Uncommon antenatal presentation of tuberous sclerosis

This is a case of a newborn male who was diagnosed in the first month of life with tuberous sclerosis following an incidental ultrasound finding of unilateral ventriculomegaly at 36+6 weeks gestation. The antenatal ultrasound scan at 36+6 weeks was performed to establish fetal lie. Subsequent fetal brain MRI showed lesions that were initially thought to be haemorrhages, but turned out to be features of tuberous sclerosis. The baby also had five cardiac rhabdomyomas and multiple ash leaf macules. This was an unusual presentation of tuberous sclerosis, which on average is diagnosed later (mean age of diagnosis is 5 years). It also illustrates two important points: that subependymal nodules and haemorrhage can have a similar radiological appearance on antenatal MRI and cranial ultrasound and that routine antenatal ultrasound screening will miss the majority of cardiac rhabdomyomas.

Evaluation of the prenatally diagnosed mass

With the advent of advanced imaging technologies, the field of prenatal diagnosis and counseling has grown rapidly. The use of fetal ultrasound and ultrafast magnetic resonance imaging has allowed for prenatal identification of structural anomalies as well as neoplasm. The differential diagnosis of a fetal mass is dependent upon its location and the tissue characteristics of the mass on imaging. The use of amniocentesis for chromosomal analysis and genetic testing for known tumor-related genetic abnormalities may aid in further refining the diagnosis. Herein we describe a general diagnostic algorithm for fetal masses based upon their location within the body and how the appropriate diagnostic modalities may be applied in the clinical setting.