Monitoring Pulmonary Arterial Pressure in Coronary-artery Disease

Abstract

To delineate the indications for pulmonary arterial pressure monitoring, the relationship between central venous pressure (CVP) and pulmonary capillary wedge pressure (PCWP) was examined in 30 patients with coronary-artery disease and ventricular dysfunction (ejection fractions ranging from 0.26-0.84) prior to, during and after coronary-artery surgery. For each patient, 30 simultaneous measurements of CVP and PCWP were made during 36 h that included the awake state, the anesthetized state with and without surgery, before and after pericardiotomy, before and after cardiopulmonary bypass and 1, 4, 8 and 24 h after operation. Changes in filling pressures were acutely induced by changing body position to alter venous return. The CVP ranged from 0-19 torr, and the PCWP from 0-31 torr. The CVP and the PCWP correlated well (r = 0.89) during all measurement periods for patients who had ejection fractions greater than 0.50 without angiographically demonstrable ventricular dyssynergy preoperatively. Changes in CVP (.DELTA.CVP) and PCWP (.DELTA.PCWP) over the 36 h period also correlated well (r = 0.94). Normality (abnormality) of the CVP was predictive of normality (abnormality) of the PCWP for more than 96% of the 450 data points. For patients with ejection fractions less than 0.40 or with dyssynergy, the CVP did not correlate with the PCWP (r = 0.24), and .DELTA.CVP did not correlate with .DELTA.PCWP (r = 0.04). Normality (abnormality) of the CVP was predictive of normality (abnormality) of the PCWP for less than 62% of the 450 data points.