ABSTRACT
There are two pathologic forms of primary EFE: dilated, which is the most common form, and contracted.16 Dilated EFE is characterized by a markedly enlarged globular heart, mainly involving the left ventricle (LV) and left atrium (LA). The LV endocardium is opaque, glistening, milky white, and diffusely thickened reaching about 1-2 mm. The thickening is most marked in the outflow tract. Endocardial thickening extends to the LA, right ventricle (RV), and right atrium (RA). In approximately 50% of patients, the mitral and aortic valves are involved, often resulting in marked anatomic deformity and either valvar regurgitation or stenosis. The less common contracted type of primary EFE is associated with a relatively hypoplastic or normal LV size. The right and left atria and the RV may be markedly enlarged and hypertrophied. An early event in fetal life is believed to result in dilated EFE, which later changes to a contracted type16 (Figure 33.1). The same process may affect the RV myocardium. Figure 33.2 illustrates a case of a contracted form of RV EFE (Video 33.1). In this case, the fetus presented with noncontractile and slightly hypoplastic RV with functional pulmonary atresia. Runs of supraventricular tachycardia and hydrops were controlled with oral digoxin. The baby was born with moderate to severe RV hypoplasia and no antegrade pulmonary blood flow. RV systolic function was very poor. The first procedure performed was ductal stenting. The baby was placed on extracorporeal membrane oxygenation (ECMO) and listed for transplant but died waiting for an organ donor. His pathological specimen is depicted in Figure 33.2d. Of note, his previous sibling had presented with similar findings and died of uncontrolled arrhythmia after a Blalock-Taussig shunt.
