DISEASES OF THE SUBSTANCE OF THE HEART.
BY WILLIAM OSLER, M.D.
Malpositions of the Heart.
We shall consider only such alterations as affect the whole organ; faulty position of individual parts comes under the section upon Malformations. It may, however, be mentioned that cases are known of complete transposition of the chambers, the pulmonary artery and cavæ being connected with the left, the aorta and pulmonary veins with the right side, the valves being also transposed.1
1 Pazannuzzi, London Med. Record, 1877.
Malpositions of the heart result either from errors of development, or, more commonly, from changes in contiguous organs, usually the effect of disease.
Of the congenital anomalies only a few are of practical interest. The heart may be placed vertically in the chest, as in the foetus, the apex beating at the lower end of the sternum; or, more rarely, the organ lies transversely. Dextrocardia, the condition in which the heart is on the right side of the body, is much more important, and is usually associated with the transposition of the abdominal viscera—situs inversus viscerum. In these cases the apex-beat is in the region of the right nipple; a distinct area of dulness can be obtained to the right of the sternum, in which situation the heart sounds are loudest; and, lastly, there is pulmonary resonance in the place of normal cardiac dulness. In the great majority of cases—70 out of 782—the abdominal organs are also transposed, the liver on the left side, the spleen on the right; but in a few instances the heart alone has been misplaced, and under such circumstances care is needed to diagnose the condition from dislocation of the organ due to old-standing lung disease with retraction.