Electrokymographic Observations in Constrictive Pericarditis

The advances which have been made in cardiac surgery in the past two decades emphasize the importance of early recognition of restriction of diastolic filling of the heart due to pericardial disease. Critical examination of the criteria given by a number of writers (1, 2, 9, 10, 11, 12, 14) for the diagnosis of constrictive pericarditis indicates that indirect evidence is often the only kind available. In the hope of obtaining additional information of diagnostic significance, it has seemed worth while to conduct electrokymographic studies of patients with this disease. The clinical effects of constrictive pericarditis have been adequately reviewed in the literature by Beck (1, 2) and others (8, 13) and need not be repeated here. It is, however, of importance to note that signs of venous stasis and decreased stroke volume, while occurring in constrictive pericarditis, may also be observed in congestive failure, caval obstruction, and other conditions (14). The remaining component of the triad, namely, a “small quiet heart,” proved an invalid criterion in a study by Stewart, Carty, and Seal (12), who reported slight to marked enlargement in 13 out of 16 cases of constrictive pericarditis. Harrison and White (8) found slightly to moderately enlarged hearts in 19 of 37 patients with constrictive pericarditis, while 18 had hearts of normal size. It follows, therefore, that in the presence of venous stasis, reduced cardiac output, and a normal or enlarged cardiac silhouette, the diagnosis of constrictive pericarditis must be considered. The clinical consequences of chronic constrictive pericarditis are primarily the result of mechanical limitation of diastolic filling of the ventricle. There are, in general, two types of roentgen evidence which help in the establishment of this diagnosis. These are: (1) signs indicative of disease involving the pericardium and adjacent structures, capable of producing the mechanical situation postulated; (2) abnormality of the movements of the cardiac and great vessel borders consistent with this mechanical situation. Chronic disease of the pericardium is suggested by three roentgenologic observations. (1) Shell-like calcification along the cardiac borders may be seen by fluoroscopy or on the x-ray film. This calcification is not necessarily evidence of rigidity or reduction in volume of the pericardial sac. It is more often absent than present, having been reported in only 25 to 44 per cent of various series (6, 8, 11, 12). (2) Loss of distinctness, in the cardiac silhouette, of the points of junction or overlapping of the borders of the heart and great vessels is significant, since it suggests thickening of the pericardium. The shape of the heart shadow is not otherwise helpful. (3) Fluoroscopic demonstration of fixation of the mediastinum helps, since the pericardium is likely to be involved.