Angiocardiography in Congenital Heart Disease of Cyanotic Type with Pulmonic Stenosis or Atresia

The diagnosis of pulmonic stenosis and particularly of the anomaly known as the tetralogy of Fallot has become more important since the surgical treatment of this condition has been established. The operation described by Blalock and Taussig (6) consists of an anastomosis between one of the large systemic arteries arising from the arch of the aorta and the pulmonary artery on the same side. Potts, Smith, and Gibson (11) have described a variant of this procedure which accomplishes the same end, namely a side-to-side anastomosis between the aorta and the pulmonary artery. Before either of these surgical procedures may be undertaken, certain criteria must be fulfilled: (a) a pressure gradient between the systemic circulation and the pulmonary circulation sufficient to allow a satisfactory flow of blood into the pulmonary artery after anastomosis, (b) a pulmonary artery of sufficient size to permit an anastomosis on the selected side of the body, (c) a shunt of unoxygenated venous blood from the right to the left side of the heart. Some additional criteria are discussed by Taussig (20, a). When employed in connection with routine clinical procedures in patients with congenital heart disease, conventional roentgenography gives information of great value in the diagnosis of pulmonic stenosis. Fluoroscopy is of special importance, as has been emphasized by Taussig (21, b). Decreased vascular markings in the lungs associated with a concavity of the upper border of the heart to the left of the sternum permits the inference that the pressurein the pulmonary arterial system is decreased. Occasionally, however, the pressure within the pulmonary arteries may be lowered distal to a point of stenosis despite an apparently normal vascular pattern in the lungs. If the point of stenosis can be demonstrated by direct visualization, one may assume that the pressure distal to this point is decreased. Conversely, in the absence of a demonstrable point of stenosis, the pressure in the pulmonary arteries might be expected to approach that of the right ventricle. Hence, a procedure which allows accurate visualization of the pulmonary conus and proximal pulmonary artery would be of considerable diagnostic value. The pulmonary arteries may be visualized with a fair degree of clarity in normal subjects by conventional roentgenography. When the arteries are small, however, as may occur in the tetralogy of Fallot, estimation of their size or even the demonstration of their presence may be extremely difficult. It is in such instances that contrast visualization may be of great value. Although the degree of pulmonic stenosis can be estimated by cardiac catheterization and clinical methods, the presence or absence of adequate distal pulmonary arteries can only be suspected. Angiocardiography is peculiarly adapted to the solution of this problem.