Fibrinolytic therapy in bacterial endocarditis: experimental studies in dogs

An investigation was undertaken to assess the value of adding streptokinase therapy to standard penicillin treatment of artificially induced infective endocarditis due to Streptococcus sanguis. In pigs a low-grade infection could be induced which closely simulated streptococcal endocarditis in man, but for technical reasons this model proved unsatisfactory for further experimentation. In dogs the induction of S. sanguis endocarditis produced a more severe illness with a short natural history. Dogs were divided into two groups, one treated with penicillin alone, the other with penicillin and streptokinase. A five-day course, in which twice daily injections of an acylated streptokinase-plasminogen complex were given, caused a substantial reduction in the size of vegetations and possibly a higher proportion of cures and less damage to the valves. Infarction of the brain, almost certainly due to embolism, was significantly greater in the streptokinase treated group, but the same was not true of the kidneys. The possible value of such treatment for certain kinds of bacterial endocarditis in man, especially in the right side of the heart, is discussed.