Ventriculo-coronary micro-communications in pulmonary atresia and sequential changes of coronary arteries.

In the present paper, numerous micro-communications between myocardial sinusoids and small branches of coronary arteries are studied which existed in a rudimentary right ventricle of a female neonate with pulmonary atresia and an intact ventricular septum, who was born on the 40th week of gestation. Cardioangiography revealed a large fistulous subepicardial communication. At autopsy, myocardium of the right ventricle appeared spongy with extensive sinusoid slits. In addition to the large communication which was connecting a deeply extending sinusoid of the right ventricle to the main trunk of the anterior descending artery, numerous micro-communications were found between myocardial sinusoids in the rudimentary right ventricle and intramural small branches of the coronary artery. Furthermore, morphometrical analysis demonstrated that the medias of the intramural arteries in both ventricles of the present case were significantly hypertrophic, as compared with those in the control cases without communications (p less than 0.05). These facts indicate the significance of hemodynamic factors on the persistence of embryonic sinusoid-coronary communication.