Studies on the blood fibrinolytic system in congestive cardiac failure.

1. The major components of the blood fibrinolytic enzyme system were measured in patients with congestive cardiac failure, in control patients with heart disease but not in failure, and in control subjects without heart disease. 2. Heart disease in the absence of failure was associated with an increase in fibrinogen, fibrin degradation products and a,-antitrypsin, but not with any alteration of plasminogen activator, plasminogen, the serum inhibitor of plasminogen activation or a,-macroglobulin. 3. Compared with patients with heart disease, there were decreased amounts of plasminogen activator and plasminogen and increased amounts of the serum inhibitor of plasminogen activation and the antiplasmin a,-antitrypsin in patients with cardiac failure. Fibrinogen, fibrin degradation products and a,-macroglobulin were not significantly altered. 4. Plasminogen activator as measured by the euglobulin lysis time correlated inversely with the height of the jugular venous pressure, but not with liver size, the extent of oedema, chest X-ray appearances, amounts of blood urea or bilirubin. 5. The release of plasminogen activator in response to venous stasis was decreased in patients with cardiac failure.