JE: Graded pulmonary vascular changes and hemodynamic findings in cases of atrial and ventricular septal defect and patent ductus arteriosus. Circulation 18: 1155

With use of a previously described system of grading, a study was made of the relation between each of the grades of hypertensive puluonary vascular disease and the hemio-d(ynamine findings in the lesser circulation in 15) cases of atrial septal defect, 19 cases of ventricular septal defect, and 6 cases of patent ductus arteriosus. TN A previous paper ' 6 histologic grades of hypertensive pulmonary vascular disease were defined on the basis of studv of 67 cases or congenital septal defect of the heart and 2 eases of idiopathic pulmonary hypertension. In 40 of these 67 eases of atrial or ventrieu-lar septal defect or patent ductus arteriosus, detailed pihysiologic studies had been carried out. These data are now employed to demon-strate the relation of each grade of the sug-gested pathologic classification to the level of Julmonary arterial blood pressure and flow and to age. In many instances the physiologic (lata were obtained while the patient was lbreathing air and 100 per cent oxygen re-sp)eetiv ely. Similar data from 3 cases of idio-I)ctllie pulmonary hypertension, 2 of which were included in the previous paper, are in-cili(led for purposes of comparison. METHODS AND MATERIAL l'orty cases were studied and these were sub-(livided into 2 groups according to the type of seIptal defect present. The first group consisted of 15 patients with itnteraltrial conununication (eases 1 to 15). Their ages ranged fronm 10 to 55 years. Patients 1 to S had an atrial septal defect of the foramen oval