Congenital cardiac disease associated with polysplenia. A developmental complex of bilateral "left-sidedness"

The well-recognized association of congenital cardiac disease with asplenia has been termed "bilateral right-sidedness" or dextro-isomerism, since the spleen is absent, the liver is symmetrical, and each lung has three lobes and an epiarterial bronchus. In a study of pathological material from 12 patients with congenital cardiac disease associated with multiple spleens (as contrasted to accessory spleen), we found a definite tendency for the symmetrical development of organs but with a tendency for bilateral left-sidedness or levo-isomerism.

The abnormalities assumed one of three forms as follows: (1) absence of a normal right-sided structure, (2) bilateral organs, each with the structure of a left-sided organ, or (3) excessive tissue of a left-sided organ. Thus, in polysplenia we observed a tendency for (1) absence of the hepatic segment of the inferior vena cava and absence of the gallbladder, (2) two lobes in each lung with hyparterial bronchi, and (3) multiple spleens. Other noncardiac abnormalities were partial or complete abdominal heterotaxia and partial malrotation of the bowel. The cardiac malformations included dextrocardia, bilateral superior venae cavae, anomalous pulmonary venous connection with malposition of the atrial septum, and defects in the atrial septum and in the ventricular septum.

Our study suggests that the developmental complex of multiple spleens is closely related to the asplenic syndrome, with the important difference being left-sided symmetry rather than right-sided symmetry.

Infarction of papillary muscles and mitral insufficiency associated with congenital aortic stenosis

Study of the papillary muscles in 11 infants dying in the first year of life with congenital aortic stenosis and normal coronary arteries demonstrated infarction of the left ventricular papillary muscles in each. Lesions were more extensive in the posteromedial than in the anterolateral papillary muscle.

Infarction of papillary muscles is considered the basis for the common occurrence of mitral insufficiency in symptomatic infants with congenital aortic stenosis. Congenital aortic stenosis, infarction of left ventricular papillary muscles, and mitral insufficiency are so interrelated as to constitute a syndrome.