Roentgen Kymographic Studies of Cardiac Conditions

Abstract

ROENTGEN kymography is an objective and accurate method of recording the physiological movements of an organ or structure on a single x-ray film. The original idea was conceived by Bronislaw Sabat (1), in 1911, when he was a physiologist in Warsaw, Poland. The American pioneer in the development of this work was A. W. Crane (2), of Michigan, who, in 1915, presented his kymograph, elucidated the principles of kymography, and pointed out its application in the study of heart disease. In 1928, Pleikart Stumpf (3), of Munich (Fig. 1), made and later perfected a kymograph with multiple slits. By 1931 (4) he had developed the procedure so that it was practical and of clinical value. I. Seth Hirsch (5, 6) introduced multiple-slit kymography to this country in 1934, improved the technic, and made important clinical contributions. It was his work that stimulated our interest in kymography. The procedure is simple (Fig. 2). The essential part of the apparatus is a large lead sheet in which narrow, horizontal slits are cut every 12 mm. apart. Each slit is 0.4 mm. in width, as advocated by Hirsch. This sheet is called the “grid.” In our technic it is stationary. The film or cassette is placed behind the grid, and during a single, continuous exposure of about one and one-fourth second the x-ray film slowly moves down behind the grid a distance slightly less than the space between the slits, or actually 11 millimeters. This leaves 1 mm. of white, unexposed film which divides the kymogram into frames and prevents an overlapping of exposures. It must be clearly understood that it is the movements of only those areas on the border of the heart that overlie a slit which are recorded on the film as it moves down behind the grid. For a more detailed discussion of the apparatus2 and discussion of the principles of kymography, the reader is referred to previous articles (7, 8) and to the papers of Hirsch and Johnson (9). Figure 3 is a kymogram of a normal heart. Each frame is a record of the movements of the small area on the heart border which was opposite a slit during the time the heart filled and emptied. Each wave is one cardiac cycle. The lower leg of each wave is the record of diastole and the upper leg, of systole. Since the slits in the grid are equally spaced and the film moves at a uniform rate, all points on any wave that are equidistant from a white line at the bottom of any frame, occurred at the same instant. By measuring these distances in various frames, it is thus possible to determine the time relationship of the movements that occur in the different cardiac chambers. For example, ventricular systole begins at the peak of the waves and moves medially. If we measure this same distance from the peak to the white line at the bottom of the frame in the aortic area, we see that the aorta is filling outward as the result of the ventricular contraction.