RELATION BETWEEN PULMONARY VENOUS FLOW AND PULMONARY WEDGE PRESSURE -INFLUENCE OF CARDIAC-OUTPUT

Multiple factors affect the systolic and diastolic components of pulmo nary venous flow. It has been suggested that left ventricular function might influence the effects of filling pressures on indexes of pulmon ary venous flow. The present study was designed to evaluate the effect of the pulmonary wedge pressures, left ventricular function, and card iac output on the pulmonary vein flow pattern. Forty-five patients und ergoing cardiac surgery were included in this study. Pulmonary venous flow and mitral flow variables were obtained by transesophageal echoca rdiography with hemodynamic variables obtained simultaneously. In the total group, there was no consistent relation between the pulmonary ve nous flow or the mitral flow parameters and the capillary wedge pressu res. When patients were grouped according to normal (>2.2 L/min/m(2)) or low (<2.2 L/min/m(2)) cardiac index, a significant and positive rel ation was found between the systolic component of the pulmonary venous flow and the pulmonary wedge pressure in patients with normal cardiac index (r=0.69; p = 0.003). Conversely, in patients with low cardiac i ndex there was also a significant although negative correlation betwee n the systolic velocity integral and the pulmonary wedge pressure (r=- 0.58; p < 0.001). In conclusion, the systolic component of the pulmona ry venous flow correlates closely and significantly with the capillary wedge pressures. The direction of this relation depends to a large ex tent on the total cardiac output and to a lesser extent on the left ve ntricular systolic function as assessed by the ejection fraction.