Roentgen Diagnosis of Cardiac Competence

The classification of disease serves a useful purpose only if it furthers the understanding of the pathologic process or aids in diagnosis, prognosis, or treatment. Often the functional classification of heart disease is utilized by clinicians to the detriment of all these principles. We have been impressed on a number of occasions by the disparity between the functional state of the diseased heart and the physiological status as determined by catheterization. The roentgen appearance of the chest correlates well with the physiologic data and roentgenography is a simple method of following the patient's progress and response to therapy, though there have admittedly been cases where interpretation of the roentgen findings has been in error. When there is disagreement between the clinical and radiographic evaluation, there is a need for amplifying studies. The radiographic factors to be considered are cardiac size and configuration, pulmonary venous appearance, pulmonary arterial appearance, and the presence of failure as manifested by interstitial and free fluid. An accurate localization of the cardiac abnormality is, of course, mandatory for a meaningful evaluation of the pathologic status. For example, the patient with aortic stenosis and signs of pulmonary venous congestion is in a much more advanced stage of disease and has a poorer prognosis than the patient with mitral stenosis and similar findings. Pulmonary Veins The pulmonary veins are an accurate gauge of the pressure within the left atrium, when this is low or moderately elevated (9). Left atrial pressures below 16 mm. of mercury produce distention of both upper and lower lobe veins proportional to the pressure (Figs. 1 and 2). Above 16 mm. of mercury the upper lobe veins continue to enlarge (Fig. 3). The lower lobe veins have been described by other investigators (11) as constricted at the higher pressures. In our material the behavior of these veins has been inconstant. Apparent constriction and dilatation have each been observed. In failure, venous dilatation appears to predominate. At very high pressures, that is, above 30 mm. of mercury, we make no attempt to indicate the exact pressure level. The veins in the upper lobes are distended (Fig. 4). We have seen only a few cases in which there has been apparent constriction of the upper lobe veins with elevated pressure. Pulmonary Arteries Pulmonary arterial hypertension is accompanied by alterations in the size and configuration of the arterial shadows in the lung fields (14). Constriction of the peripheral arteries associated with rapid tapering of the secondary and tertiary arteries has been described (1–6). There is often an accompanying enlargement of the central arterial trunks, producing disparity between the peripheral and central lung fields (12, 13).