CLINICAL PROGRESS Diagnosis of Diffuse Myocardial Fibrosis

SIXTY-EIGHT patients with constrictive pericarditis were studied by this laboratory in a 30-year period. During this time 14 patients were encountered whose findings suggested constrictive pericarditis but who showed an abnormal myocardium at operation or autopsy. Two of these patients had both constrictive pericarditis and myocardial fibrosis, each of the other 12 had a no: mal pericardium. The hemodynamic aspects ore diffuse myocardial fibrosis as exemplified in 10 of these patients have been described by Robin and Burwell." 2 The purpose of this paper is to describe the course and manifestations of diffuse myoeardial fibrosis in these 14 patients, to discuss the diagnosis of this disorder, and to consider the differentiation of myocardial fibrosis from constrictive pericarditis. The fact that constrictive pericarditis is to some degree remedial by surgery makes this differentiation of high importance. Myocardial fibrosis is defined as a diffuse replacement or invasion of the myocardium by fibrous connective tissue to such an extent that there is interference with the action of the heart. It may be expected that the nature, location, and extent of such fibrosis will influence its manifestations in a given patient.