Pattern of blood flow in the pulmonary veins of the dog

Abstract

The pattern of blood flow in the large pulmonary veins was studied in dogs by chronic implantation of sine-wave electromagnetic flowmeters and cineangiographic observations. These revealed that: 1) pulmonary venous flow is continuous and pulsatile with peak rate of flow of approximately twice the mean flow; 2) the initial rapid increase in venous flow occurs 0.10 sec after the onset of ventricular systole, reaching a peak at the time of closure of the A-V valves; 3) left atrial contraction produces a fleeting slowing or reversal of flow; and 4) respiratory variations in pulmonary venous flow follow those in pulmonary arterial flow, beat by beat. The genesis of phasic pulmonary venous flow was investigated by analysis of pressure and flow curves from the two sides of the heart, by consideration of the energy required for left ventricular filling, and by reconstruction of the pulmonary venous flow pulse using a mathematical model of the pulmonary circulation. These three lines of evidence are consistent in indicating that the transmitted right ventricular pressure is the major determinant of the pulmonary venous flow pattern in the dog. pulsatile pulmonary venous flow; pulmonary venous flow; pulmonary circulation; ventricular suction; respiration on pulmonary circulation; pulmonary venous angiography; pulmonary veno-atrial junctions; electromagnetic flowmeter; cineangiography Submitted on November 16, 1964