Circulatory Changes in Chronic Pulmonary Disease *

With the demonstration by Bing and associates that extensive collateral circulation between systemic and pulmonary arteries develops in some types of cyanotic congenital heart disease,' the question of whether other clinical states associated with cyanosis might also exhibit collateral circulation presented itself. The answer has appeared in the remarkable injection studies of Liebow and associates, who clearly demonstrated anatomically the presence of large collateral vessels in lungs taken from cases of chronic pulmonary disease.l' These vessels consist of precapillary anastomoses between bronchial arteries and pulmonary arteries. The physiological significance, that is, the extent and consequences of such additional channels, remained to be demonstrated. Such demonstration, together with observations of other circulatory phenomena associated with chronic lung disease, constitute the purpose of the present report.