Rheumatic Mitral Valve Disease Without Cardiac Enlargement

Abstract

In the diagnosis of mitral valve disease, radiologic aid is frequently sought. This is usually based on the various roentgen evidences of change in the size or contour of the heart. Although these observations may be variable and may be simulated by a variety of other conditions (1), the usual teaching at the present time is that teleradiographic examination reveals prominence of the second left cardiac arc due to prominence of the pulmonary artery and the appearance of the conus arteriosus of the right ventricle on the left heart border. Further radiologic examination in the right anterior oblique position, after the administration of a barium bolus, shows posterior displacement of the esophagus, indicative of left atrial dilatation, usually ascribed to the hemodynamic changes caused by the malformation of the mitral valve. Left atrial dilatation is considered by some to be next in importance only to the pathognomonic apical diastolic murmur as a criterion for the diagnosis of mitral valve disease (2). Various measurements of the frontal silhouette of the heart viewed teleradiographically are often used for the determination of cardiac enlargement. The most reliable of these are the Ungerleider and Gubner charts and nomograms, which are reported to be the only measurements which can identify as little cardiac enlargement as 40 per cent above the normal heart weight (3). Ungerleider presents these methods as two simple and accurate procedures whereby the presence of cardiac enlargement may be determined, and also states that cardiac fluoroscopy is an invaluable aid in the diagnosis of chamber enlargement (4). Recently mention was made of the fact that dilatation of the left atrium may exist in certain cases of rheumatic mitral valve disease without visible or arithmetic changes in the frontal silhouette of the heart (5). In these patients left atrial dilatation may be demonstrated only by the posterior displacement of the esophagus viewed in the right anterior oblique position. This was considered to be the earliest radiologic sign of mitral valve disease and incidentally poses the question whether dilatation of any chamber of the heart should not be considered indicative of enlargement, whether or not it might be identified by any of the methods of cardiac mensuration. The purpose of this communication is to report a group of cases with the classical systolic .and diastolic murmurs of mitral valve disease but without any radiologic evidence of cardiac enlargement. These were selected from a larger group with sufficient but not absolutely definite evidence of mitral valve disease, The latter group likewise presented no radiologic evidence of cardiac enlargement. It is emphasized that under these conditions the radiologist should report only that the heart is neither visibly enlarged nor altered in contour; he should not attempt to pass on the existence of organic heart disease on the basis of his findings alone.