Abstract

Two dimensional alignment of valves in the cardiac skeleton is studied using 49 fetal hearts. They are standardized with fixed length between the centers of mitral and tricuspid valves. The relations among the parameters and of wall thichness ratio are studied, especially by the change of gestational age, mitral aortic distance and pulmonary-aortic distance, the angles between the two lines and mitral-tricuspid line. Anterior shift of great vessels was seen in heart with gestational age less than 20 weeks. Long mitral-aortic distance showed anterior shift of the great arteries and left ventricle was relatively thicker than right ventricle. Narrow aortomitral-tricuspid angle denoted posterior shift of great vessels and thich right ventricle. Short pulmonary-aortic distance denoted antero-posterior alignment and posterior shift of the vessels and thick left ventricle. Left-right alignment of vessels was not associated with right-ward shift but only with pulmonic displacement to the left. By these observation abnormal alignment of valves in cardiac skeleton would be a basic defect in bulboventricular malformation and we could find basic difference of cardiac skeleton, between normal variation and abnormal heart.

• Keywords: Cardiac development;Cardiac skeleton;Bulboventricular malformation;