Ebstein’s malformation of the tricuspid valve

Ebstein’s anomaly of the tricuspid valve is a rare congenital anomaly (1 in 200 000 live births) and is defined by the septal insertion of the tricuspid valve leaflet being >8 mm/m2 apically displaced from the septal insertion of the mitral valve leaflet. This is due to adherence of the septal leaflet to the ventricular septum secondary to failure of delamination. The inferior–posterior, and occasionally anterior, leaflet may also be displaced and rotated. The anterior leaflet is frequently part-redundant and may be fenestrated. Leaflets may be dysplastic or tethered, altering the surgical options. Ebstein’s anomaly may result in enlargement of the native and functional right atrium, enlargement of the functional right ventricle, left ventricular compression, arrhythmia, sudden death, and heart failure. Cardiovascular magnetic resonance (CMR) enables accurate quantification of right and left ventricular volumes and function, cardiac output, and cardiac shunt from measurement of Qp:Qs. CMR is highly informative regarding the anatomy and function of the tricuspid valve, in particular when the degree of displacement and/or rotation of the tricuspid valve is more than mild to moderate.