Pulmonary Blood Volume in Congestive Heart Failure
By utilizing indicator-dilution techniques, determinations of the pulmonary blood volume (PBV) and central blood volume (CBV) were made in 25 patients during simultaneous right and transseptal left heart catheterization. Of these, 12 patients had normal hemodynamics, six had heart failure associated with mitral stenosis, and seven had heart failure secondary to nonvalvular myocardial disease.
In the normal patients the PBV averaged 271 ml/m2 (se, ±10.0) and the CBV 596 ml/m2 (se, ±25.7). The mean value for PBV and CBV in the patients with heart failure associated with mitral stenosis was 238 ml/m2 (se, ±26.3) and 600 ml/m2 (se, ±40.9), respectively. Among the patients with nonvalvular heart failure the PBV averaged 292 ml/m2 (se, ±21.4) while the CBV averaged 679 ml/m2 (se, ±45.8). In 12 of the 13 patients with heart failure, the individual values for PBV and CBV did not differ significantly from normal. However, in each of the 13 patients pulmonary artery, left atrial, and mean pulmonary distending pressures were significantly elevated, whereas the relative pulmonary vascular compliance was greatly reduced.
These findings indicate that the pressurevolume relationships within the pulmonary vascular bed are greatly altered in the presence of chronic pulmonary venous hypertension. Normal values for PBV were associated with significant pressure elevations in the presence of pulmonary congestion and edema.
It is concluded that in the pathogenesis of heart failure elevations in pulmonary vascular pressures play a dominant role while changes in PBV are of but secondary importance. These findings do not support many of the traditional concepts regarding the role of pulmonary blood volume changes in the pathophysiology of heart failure.
- © 1966 American Heart Association, Inc.