Isolated myocarditis

Abstract

There is a type of myocarditis of unknown origin which is not accompanied by endo- or pericarditis. It occurs in patients who have no other disease that may be correlated with the myocarditis. This myocarditis may also be present in apparently healthy persons who, more or less suddenly, develop progressive myocardial weakness and succumb quickly. Clinically, the outstanding manifestations, in addition to the progressive myocardial failure, are a weak, rapid pulse, low arterial pressure, and an increase in the area of cardiac dullness. Precordial pain may be present. The disease occurs at any age, although young people seem more frequently affected. Therefore, arteriosclerotic heart disease can easily be ruled out. There is no history of rheumatic fever. The patients often die suddenly. Of thirteen patients in this series, ten succumbed suddenly. It seems that clinicians, for some reason, rarely, if ever, diagnose the myocarditis. Anatomically, isolated myocarditis does not vary in histologic details from the myocarditis which is occasionally encountered in the course of acute infectious disease. A diffuse and a granulomatous type can be distinguished. The latter is much rarer, and morphologically somewhat resembles the granulomas of tuberculosis and syphilis. Histologically, many giant cells (muscle giant cells) are often recognized. The minute granulomas which are seen in trichinous myocarditis may also occur in isolated myocarditis. Although nothing is known as to the cause of either the diffuse or granulomatous form, it seems imperative in every instance to examine histologically other organs and structures besides the heart in pursuit of the causative agent, as in trichinosis, or, perhaps, tularemia. Lately, a hypersensitivity, particularly to arsenic compounds (arsphenamine and salvarsan), has also been regarded as responsible.