Abstract
The pulmonary artery pressure response to tilting feet-down at an angle of 45° from the horizontal was studied on 37 patients : 20 cases of pulmonary disease, 17 cases of cardiac disease. The pressure response were put into three patterns ; type I, type II and type 0, which were classified by J. Mise previously. Type I : In ten minutes after tilting, the pulmonary artery pressure decreased gradually from 5 to 25mmHg, in 17 cases. The left ventricular failures such as mitral insufficiency and aortic insufficiency which have high wedge pressure were included in type I. The promotion of venous return to the left heart may be considered as a main cause of this pressure response.Type II : In 5 cases, the pressure rose more than 4mmHg over the control level after tilting. These five were cases of pulmonary hypertension due to pulmonary emphysema (1 case), bronchial asthma (2 cases), pheochromocytoma (1 case) and tight mitral stenosis (1 case). All of them had low wedge pressure except a case of tight mitral stenosis. Reflex restriction of the pulmonary vascular bed may be considered as a main cause of the pressure increase.Type 0 : Cases of pulmonary fibrosis, silicosis, moderate or slight mitral stenosis, pulmonary tuberculosis which had undergone operations such as lobectomy and thoracoplasty, and healthy cases were included in type 0.The systolic, diastolic and mean pressures of the pulmonary artery changed almost in a parallel manner in all of these types. The pulse pressure, however, of the pulmonary artery decreased after 45° tilting in almost all cases.The diagnostic value of these response patterns of pulmonary artery pressure due to a change from a horizontal position to a 45° tilt, was discussed.
