The vascular pedicle of the heart and the vena azygos. Part II: Acquired heart disease.

To establish the value of the chest radiograph in assessing the hemodynamic status of the systemic circulation, the vascular pedicle width ( VPW ) and vena azygos width (AW) were correlated with total blood volume (TBV) and other parameters in 61 cardiac patients. In both ischemic and valvular cardiac disease a highly significant linear correlation was found between VPW and TBV (r = 0.80, p less than 0.001). In patients with dilated neck veins VPW was greater than 62 mm (normal 48 +/- 5 mm). A less significant correlation was found between VPW and mean right atrial pressure ( MRAP ). Change in VPW correlated strongly (r = 0.93, p less than 0.001) with change in TBV (0.5-cm change in VPW = 1.0-liter change in TBV). Correlation between AW and TBV was poor (r = 0.50, p less than 0.01), but between AW and MRAP the correlation was stronger (r = 0.74, p less than 0.001). Changes in AW usually occurred in the same direction as changes in MRAP , but the correlation was not significant (r = 0.45). VPW and AW did not correlate with pulmonary blood volume, pulmonary arterial pressure, stroke volume, or heart rate. Radiologic assessment of VPW and AW adds an additional clinically useful dimension to the evaluation of cardiac disease.