Myocarditis and myocardial hemorrhage associated with thrombotic thrombocytopenic purpura.

Four patients with thrombotic thrombocytopenic purpura (TTP) developed severe cardiac dysfunction. Endomyocardial biopsy in one patient demonstrated focal myocarditis associated with platelet microthrombi. Cardiac function and TTP improved after plasmapheresis therapy in this as well as in two other patients. A fourth patient died owing to extensive intramyocardial confluent hemorrhages. Cardiac involvement in TTP may be due to microvascular thrombosis, hemorrhage, or myocarditis. Severe myocardial dysfunction may improve with treatment aimed at the underlying hematologic disorder.