The Importance of the Lateral View in the Evaluation of Left Ventricular Enlargement in Rheumatic Heart Disease

Surgical relief for patients with mitral valve lesions resulting from rheumatic fever is still much more effective in mitral stenosis than in mitral insufficiency; the surgical approach to mitral insufficiency is used only to a limited extent. The estimation of the degree of insufficiency in a mitral lesion is thus an important factor in determining whether or not a patient will benefit from surgery. In addition, those patients who are to undergo operation for mitral insufficiency will frequently require pump-oxygenator apparatus. The detection of enlargement of the left ventricle in the lateral view has been the most reliable single indicator of mitral insufficiency in our material. The fact that enlargement of the left ventricle occurs more posteriorly than laterally has long been recognized (8). Indeed, this is implicit in the evaluation of left ventricular size in the left anterior oblique projection. Less attention has been given to the lateral view. McKay and Aitchison (6) made use of the esophagus as a landmark in detecting posterior enlargement of the left ventricle. They described a translucent space between the heart and lower esophagus in a high percentage of cases of pure mitral stenosis but found this less frequently in the presence of an associated lesion capable of causing left ventricular hypertrophy. Jacobson and others (3) have made similar observations. Dealy (1) has used the typical shape of the heart in the lateral projection as one of his criteria. Lehman and Curry (5) described the appearance of the heart in the lateral view at some length; particularly pertinent to this study is their description of the “intrusion” of the heart into the postero-inferior cardiac recess. They felt that they could not distinguish whether atrium or ventricle was responsible for this configuration. We have re-examined the films of 214 cases of rheumatic valvular disease, surgically explored, for which suitable lateral views of the chest were available. In this material, the lateral view of a patient with mitral stenosis usually shows a short segment of the heart in contact with the left leaf of the diaphragm (Fig. 1, A). The posterior aspect of the heart is of a sigmoid shape, there is often a clear space between the heart and the barium-filled esophagus, and the heart does not protrude more than 10 mm. behind the upper end of the inferior vena cava. The posteroanterior view (Fig. 1, B) shows upper lobe venous distention but, in spite of obvious increase in transverse cardiac diameter, there frequently does not appear to be any definitely abnormal position of the apex. Not all these features, however, are incorporated in the lateral view in every case of pure mitral stenosis.