Background: Ebstein´s anomaly is a rare congenital heart disease, characterized by the downward displacement of septal leaflet of tricuspid valve and atrialized right ventricule. This in turn causes right atrial enlargement, as well as dilation of the “atrialized” portion of the right ventricle above the functional tricuspid valve orifice, where the tissue is thin-walled, and while the distal functional ventricle is small.This anomaly accounts for <1% of all congenital heart defects. The etiology is uncertain (fetus exposed to maternal lithium? gene mutations for myosin heavy chain MYH7?). Patients with Ebstein´s anomaly also have arrhythmias and conduction system abnormalities, such as accessory pathways that generate a manifest pre-excitation on the electrocardiogram.Clinical presentation can vary from the most extreme form in fetal life or cases critically at birth who need intensive care and surgical interventions, in the neonatal period, to asymptomatic diagnosis late in adult life. The age at presentation is dependent on the severity of anatomic and haemodynamic derangements. Fetal and neonatal presentation in Ebstein’s anomaly is predicted to have a poor overall prognosis.Case presentation summary: Case 1. A 36-year-old pregnant woman (20 weeks´ gestation) was referred for a fetal echocardiogram in view of fetal cardiomegaly and intrauterine growth retardation detected by obstetric sonography. Assessment of maternal risk factors was undertaken without detecting problems (diseases, infections, medication, or drug use). Her two previous children were healthy. The fetal echocardiogram showed Ebstein´s anomaly (Carpentier type D), with atrial septal defect (secundum type), severe tricuspid regurgitation, mild pericardial effusion, without arrhythmias. The Celermajer index was > 1.5 (grade 4). The genetic study from amniocentesis was normal. Spontaneous intrauterine fetal death occurred at 32 weeks' gestation.Case 2. A 12-year-old female, who was otherwise healthy and has no significant past medical history, presented 3 vasovagal syncopes in the last 2 months, without palpitations. Vasovagal syncope in adolescence is usually harmless and requires no treatment, but as the patient practiced competitive sports, she was referred to a cardiologist. Physical examination revealed an incidental grade 1/6 systolic murmur, and the ECG showed a Wolff-Pakinson-White pattern. Echocardiography revealed the features of Ebstein´s anomaly (Carpentier type C), Celermajer index was > 1.5 (grade 4). Electrophysiology study is pending to assess accessory pathway ablation. (picture)Learning points discussion:1.- Echocardiography stands as the primary diagnostic tool for the evaluation of Ebstein´s anomaly: different anatomic and hemodynamic variables.2.- Ebstein´s anomaly underscores the fundamental relationship between tissue structure and arrhythmogenesis.3.- Ebstein´s anomaly is associated with a worse prognosis when it presents early as right-sided heart failure in the fetus (Celermajer index > 1.5).4.- Older patients may remain asymptomatic, but must keep under close follow-up in adult life.
