No abstract

IN THE past few years several reports on the physiologic changes in ventricular septal defect with increasing age, based on serial cardiac catheterization studies, have appeared in the literature.'-'0 The results of these investigations have not been uniform, and variable conclusions have consequently evolved. A number of workers' 4-6 suggested that progressive pulmonary hypertension and rapidly increasing pulmonary vascular obstruction hardly occur in childhood, whereas others7-9 indicated that these changes are not uncommon at this age. Recently, Lucas et al.'0 demonstrated varying hemodynamic changes in large ventricular septal defects, which they related to variations in the maturation process of the pulmonary vascular bed. This paper is a continuation of previous communications from this Departmentl-3 on the serial hemodynamic findings in ventricular septal defect. To date, a total of 75 patients with isolated ventricular septal defect have had serial cardiac catheterization studies. The results confirm our previous observation that there is a distinct tendency for the elevated pulmonary artery pressure and pulmonary blood flow to fall in the first few years of life. By the second half of the first decade or later, these changes are rarely ob-

The cardiac catheterization and angiocardiographic findings in 12 cases with bilateral stenosis of the primary pulmonary artery branches are described. Characteristic pressure tracings were consistently obtained from the main pulmonary trunk in all cases. These typical curves were reproduced in animal experiments. Associated lesions with left-to-right shunts and mild pulmonary valvular stenosis did not alter the characteristics of the curves. An attempt is made to explain these hemodynamic phenomena. These tracings obtained from the main pulmonary trunk appear to us to be diagnostic of bilateral stenosis of the main pulmonary arteries even if, as frequently happens, one is unable to enter both pulmonary artery branches during cardiac catheterization or to demonstrate definitely the stenosis of both pulmonary arteries by angiocardiography.