Corrected Transposition of the Great Vessels with Ebstein Malformation of the Left Atrioventricular Valve

Contemporary management and outcomes in congenitally corrected transposition of the great arteries

Congenitally corrected transposition of the great arteries (ccTGA) can occur in isolation, or in combination with other structural cardiac anomalies, most commonly ventricular septal defect, pulmonary stenosis and tricuspid valve disease. Clinical recognition can be challenging, so echocardiography is often the means by which definitive diagnosis is made. The tricuspid valve and right ventricle are on the systemic arterial side of the ccTGA circulation, and are therefore subject to progressive functional deterioration. The natural history of ccTGA is also greatly influenced by the nature and severity of accompanying lesions, some of which require surgical repair. Some management strategies leave the right ventricle as the systemic arterial pump, but carry the risk of worsening heart failure. More complex 'double switch' repairs establish the left ventricle as the systemic pump, and include an atrial baffle to redirect venous return in combination with either arterial switch or Rastelli operation (if a suitable ventricular septal defect permits). Occasionally, the anatomic peculiarities of ccTGA do not allow straightforward biventricular repair, and Fontan palliation is a reasonable option. Regardless of the approach selected, late cardiovascular complications are relatively common, so ongoing outpatient surveillance should be established in an age-appropriate facility with expertise in congenital heart disease care.

Congenital malformations of the mitral valve

Congenital malformations of the mitral valve may be encountered in isolation or in association with other congenital heart defects. Each level of the mitral valve complex may be affected, according to the embryological development, explaining the fact that these lesions are sometimes associated with each other. As a perfect preoperative assessment is of importance, good knowledge of both normal and abnormal anatomy is required in order to guide the surgeon accurately. This review presents the different embryological, anatomical and echocardiographic aspects of the congenital mitral anomalies.

Massive congenital tricuspid insufficiency in the newborn

Three cases of massive congenital tricuspid incompetence in the newborn are reported and discussed from diagnostic, pathologic and etiologic points of view. The diagnosis is important as cases have been reported with spontaneous resolution.

Mitral valve malformation of Ebstein type in absence of corrected transposition

The first documented case is reported of mitral valve malformation of the Ebstein type in the absence of corrected transposition. In this case, the ring of the inferior leaflet of the mitral valve was displaced downward into the left ventricle, dividing the latter into a proximal atrialized and a distal effective ventricular chamber. The anterior leaflet was not displaced. The chordae tendineae of both leaflets were thickened. The papillary muscles were hypertrophied and abnormal in architecture. The outflow tract of the effective left ventricle was shortened. The valve leaflets were thickened, and the mitral valve was probably insufficient.

Systemic atrioventricular valve regurgitation in corrected transpositon of the great vessels. Angiographic differentiation of operable and nonoperable valve deformities

Abnormalities of the systemic atrioventricular (A-V) valve are frequently present in patients with corrected transposition. Systemic A-V valve regurgitation is usually present and may be amenable to operative correction with valve replacement if the regurgitation is caused by normally positioned but deformed valve leaflets or a dilated valve ring, or both. Systemic A-V valve regurgitation secondary to the more common Ebstein-type malformation of the inverted tricuspid valve is an inoperable conditon at present. Displacement of the valve leaflets below the level of the valve ring may be seen in the angiocardiograms of patients with this finding and is the differentiating feature between the two lesions. Ten cases of systemic A-V valve regurgitation in patients with corrected transposition are reviewed to illustrate these features.