An Official Journal of the American lieart Association Spectrum of Congenital Cardiac Anomalies Produced in Chick Embryos by Mechanical Interference with Cardiogenesis

• Direct surgical manipulation of the de-veloping embryo heart is one of several physi-cal and chemical methods that are known to produce congenital cardiac anomalies in ex-perimental animals.1'2 This procedure involves the concept that the pattern of blood flow through the embryonic heart is of prime importance in cardiogenesis. It is thought that the primitive cardiac tube is molded by the streaming of blood through it, thus deter-mining subsequent development and loca-tion of the ventricular, bulbar, and aortico-pulmonary septa.3"5 Abnormalities in blood streaming might then be expected to produce abnormal development of the heart. Experi-mental methods designed to interfere mechan-ically with cardiogenesis should provide in-formation on the validity of this hypothesis, and should increase general knowledge con-cerning the origin of congenital cardiac defects. This report is concerned with a procedure involving temporary mechanical interference with normal cardiac development in the chick embryo. This manipulation distorted the bul-boventricular outflow tract, and produced a spectrum of congenital cardiac anomalies, including abnormal positioning of the aorta and also ventricular septal defects