PATENT DUCTUS ARTERIOSUS WITH PULMONARY VASCULAR SCLEROSIS AND CYANOSIS

Abstract

A case of a 37-year-old [male] with a patent ductus arteriosus is reported because of the development of unusual sequelae, namely; (a) cyanosis of 5 years'' dura-tion, (b) cor pulmonale, and (c) pulmonary vascular sclerosis. The cyanosis which developed during the last 5 yrs. of life was abolished by adm. of O2. This observation led to the conclusion that the arterial O2 unsaturation must be due to pulmonic changes rather than to an extracardiac shunt. Marked pulmonary vascular sclerosis, in addition to patent ductus arteriosus and cor pulmonale, was found at autopsy. That large vols. of blood may pass through a ductus arteriosus during life is established. The effect of the increase in pulmonary blood vol. was, in this case, to produce right ventricular hypertrophy and pulmonary vascular sclerotic changes. The explanation of cyanosis observed clinically remains obscure, since narrowing of pulmonary arteries and arterioles can only produce a "nozzle" effect, but cannot interfere with O2 saturation of the blood which occurs in the alveolar capillaries. The latter vessels were relatively normal in the case reported.