Normally, the septal cusps of the mitral and tricuspid valves are fixed at the same level; with Ebstein’s anomaly, this distance is increased to 1.4-3.2 cm, the tricuspid opening (fibrous ring) remains in the normal position. The shifted valves of the tricuspid valve (septal and posterior) in the right ventricle divide it into two parts: atrialized (the portion of the right ventricle between the fibrous ring and the displaced valves) and the cavity of the right ventricle itself. Defect combined with secondary DMPP or open oval window.
The two-dimensional EchoCG is the most informative in identifying this defect : 1. The septal valve is displaced into the cavity of the right ventricle in the projection of 4-chambers from the apex (more than 20 mm in adults and 15 mm in children); 2. atrialized right ventricle; 3. dilatation of the right atrioventricular orifice; 4. open oval window or DMPP (observed in 85% of cases).
When Doppler echocardiography determine the failure of the tricuspid valve, assess the magnitude of pulmonary hypertension. One-dimensional echocardiography allows visualization of an increase in right heart, a paradoxical movement of an IVS, a delayed closure of the tricuspid valve (over 0.03 s), an increase in the excursion of the anterior flap of the tricuspid valve, simultaneous location of two atrioventricular valves.