Extrinsic factors in the genesis of congenital heart disease.

The extrinsic factors responsible for the production of congenital heart malformations both clinically and experimentally are reviewed. The method to be followed in the investigation of extrinsic factors as teratogenic agents for the a heart and the great vessels both clinically and experimentally is studied. With Saxen and Rapola's work as a starting point, an hypothesis isproposed on thepathogenesis of congenital heart disease based on the alteration of the morphogenetic processes which normally participate in the development of the heart and the great vessels, such as the morphogenetic movements, growth, and degeneration, the disturbance of which originates those malformations. The most common congenital cardiopathies are interpreted by combining this hypothesis with others previously proposed by one of us (de la Cruz and da Rocha, I956; de la Cruz et al., I959, i1964) on truncoconal malformations, and ventricular and atrial septal defects. The main objectives to be attained in a programme of prevention of congenital heart disease caused by extrinsic factors are pointed out.