Reaction pattern to three stresses--electroplexy, surgery, and myocardial infarction--of fibrinolysis and plasma fibrinogen

The effects of three types of stress-electroplexy, surgery, and myocardial infarction-on blood fibrinolytic activity and plasma fibrinogen levels were studied in 10, eight, and six patients respectively. The fibrinolytic response to electroplexy consisted of an initial short increase followed in half the patients by reduced fibrinolytic activity lasting two to four days. After surgery and myocardial infarction normal fibrinolytic activity was followed by a period of reduced activity; the timing of the measurements on these patients may have precluded recognition of an initial increase in fibrinolysis similar to that following electroplexy. The fibrinolytic ;shutdown' which lasted for about 10 days in the coronary patients was evidently due to reduction of plasminogen activator, as judged by prolongation of the euglobulin lysis times as well as of the blood clot lysis times. Plasma fibrinogen levels rose in the surgical and coronary patients but not in the patients given electroplexy which indicates that fibrinolytic activity changes independently of plasma fibrinogen level. The results suggest that the fibrinolytic system exhibits a common reaction pattern to stress, irrespective of its nature and of tissue damage. They call for caution in assuming a specific causal association in acute diseases such as pancreatitis and haematemesis where similar fibrinolytic changes may be encountered.

Methodological study and a recommended technique for determining the euglobulin lysis time

The euglobulin lysis time, which is widely used to measure blood fibrinolytic activity, is shown to be sensitive to the temperature and pH at which the euglobulin fraction of plasma is prepared and also to the type of anticoagulant employed and buffer in which it is suspended. A standardized method for performing the test, which controls these variables and has been found to yield reproducible results, is described. Since, at present, data obtained with this test by different laboratories are, for the reasons given, rarely comparable, it is hoped that the method outlined may be considered suitable for general adoption.