SUBAORTIC BLIND MITRAL POUCH IN A DOUBLE-INLET RIGHT VENTRICLE

A full-term baby girl was diagnosed at birth using echocardiography to have a single ventricle with common atrioventricular valve and subaor tic ridge. On the 22nd day after birth she was admitted to hospital fo r intensive care after sudden onset of cyanosis. Three days later she died after repeated attacks of bradycardia. At necropsy the heart was examined by sequential segmental approach. Situs solitus with double-i nlet right ventricle and ventriculoarterial discordance was revealed. The left atrial floor was separated from the ventricle by a small hole leading to a translucent blind pouch, which bulged toward the subaort ic outflow tract with its hypoplastic tensor apparatus connected to th e subaortic infundibulum. The aortic valve was normal. The pulmonary t runk with a competent bicuspid valve arose from the left-sided rudimen tary left ventricle. The pulmonary blood flow was limited by a slit-li ke interventricular communication. Obstruction of the pulmonary venous return due to the natural closing of the patent foramen ovale and the mitral atresia led to her premature death.