VISIBLE PULSATION IN RELATION TO BLOOD FLOW AND PRESSURE IN THE PULMONARY ARTERY

Abstract

The size of the right pulmonary artery and the degree of visible pulsation in this artery and in the smaller branches of the middle and peripheral third of the lung fields was classified in four grades in congenital heart disease and in mitral stenosis. These observations were compared with pulmonary blood flow and pulmonary arterial pressure by cardiac catheterization. Visible pulsation was regarded as evidence of increased pulmonary flow. Pulsation in the right pulmonary artery was greatest in atrial and ventricular septal defect, in Eisenmenger''s complex, and in transposition of the aorta and pulmonary artery. It is less in P. D. A. and in pulmonary hypertension, and slight in mitral stenosis. Pulsation in the peripheral third of the lung and hilar dance were seen only in atrial and ventricular septal defects, in transposition, and occasionally in Eisenmenger''s complex. The range of pulmonary artery enlargement is as follows[long dash]largest in Eisenmenger''s complex and transposition and less in septal defects, pulmonary hypertension, mitral stenosis, and P. D. A., in this order. Increase in pressure and in flow, the result of exercise, increases the size of the pulmonary arteries. Visible pulsation is seen when there is increase in flow, whether the pressure is increased or not. In septal defects, increase of pressure has no further effect on pulsation whereas in Eisenmenger''s complex there may be A. S. D. and V. S. D. have more effect on size and much more effect on pulsation than P. D. A. has, independently of the increase of flows and pressures, because a large part of the cardiac output is forced into the arteries suddenly during systole instead of more gradually during systole and diastole. Eisenmenger''s complex has more effect on pulsation than pulmonary hypertension or mitral stenosis has, independently of flows and pressures, possibly because of increased flow in the past. A large pulmonary blood flow increases the size of the pulmonary artery and the degree of visible pulsation, whether the pulmonary arterial pressure is increased or not. A high pulmonary pressure, without a large flow, increases the size of the right and left pulmonary arteries, but has little or no effect on the degree of visible pulsation, except in Eisenmenger''s complex.