The Application of Kymoroentgenography to the Diagnosis of Cardiac Disease

In the consideration of the application of roentgenkymography to the study of the abnormal heart it is important to understand at the outset that the kymographic wave is not a mystic symbol capable of expressing the particular disease of the heart. It expresses only the movement phenomena of the heart and indicates the deviation from the normal, only insofar as the particular lesion affects the movement. Deviations of the kymographic waves from the normal may result either from: 1. Disturbances of rhythm which produce variations in the character and periodicity of the movements. 2. Intrinsic changes in the muscle itself, hypertrophy, atony, or degeneration. 3. Extracardiac influences which modify the anatomic relationships of the heart and the intrathoracic pressure changes. 4. Changes resulting from valvular defects which produce abnormal vibrations and variations in the chamber movements. (1) Changes resulting from disturbances in the character and periodicity of movement. Cardiac Irregularities.—By a study of successive cycles, the presence of disturbance in rhythm may be demonstrated by noting the variations in the amplitude and time relationships of the waves. Sinus arrhythmias, extrasystoles, auricular fibrillation and flutter, and heart block may thus be graphically demonstrated. In auricular tachycardia the compression which the waves undergo is such as to blot out their individuality, so that there is produced a blurred, serrated outline. In ventricular or nodal paroxysmal tachycardia, the auricular waves maintain a normal contour, as the frequency is not increased. Each frame over the ventricular contour contains two or more waves, depending on the rate. The wave is high and its contours steep. The diastolic limb shows a relative shortening, and approximates a straight line. There may be a slight blunting of the apex of the wave, due to a relative slowing up of the presystolic outward movement. The sound phenomena vibrations are not usually visualized. Ventricular extrasystoles may be recognized by finding over the left ventricular contour, an interruption of the sequence of regular waves, by a wave of smaller amplitude, the extrasystole. This is followed by a wave of enlarged amplitude with a slow diastolic rise. The systolic limb of the extrasystole is relatively slow as compared to the normal wave preceding it while that of the compensatory wave, after the extrasystole is longer than normal. The extrasystolic wave appears earlier in the apical than in the basal portion of the heart and travels upward. The corresponding change in the movement traced by the aorta depends upon the time relationship between the premature beat and the normal beat which preceded it.