Clinicians differ regarding the value of percussion of the heart borders. Many feel that accurate determination of the borders is well nigh impossible, especially in the obese and in women, while others maintain that a high degree of accuracy may be obtained by percussion. However, difficulties are recognized when percussion for the heart borders is attempted in persons with greatly enlarged hearts and those having pulmonary emphysema.
With the advent of the roentgen ray, much accurate information has been obtained in determining the borders of the heart. One is now able to learn the position of the heart in relation to the transverse diameter of the thorax. It is also possible, by means of the orthodiagram or teleroentgenogram, to determine to a high degree of accuracy the absolute size of the heart. However, the front view of the heart and aorta fails to give us the position of the heart