From the works of Kussmaul. Rauchfuss and Illoussous regarding the duration of life, Vierordt calculated an average life of from 12 to 13 years for pulmonary stenosis with simple complications. At least one half of the children with pulmonary stenosis die before the tenth year. When combined with tuberculosis, the duration of life is apparently greater (about 1S years), an apparent contradiction, which is, however, explained by the fact that pulmonary stenosis is only complicated by tuberculosis later in life, at a time when most of the children with pul monary stenosis have already died.
In a case described by Gutkind, a child with complete absence of the pulmonary artery lived for six years.
Symptomatology and Diagnosis.— Physical Signs.—The physical signs are increased cardiac dulness on percussion and abnormal auscul tatory phenomena. Stress should be laid upon eccentric hypertrophy of the right side of the heart, which is as a rule but little pronounced in early childhood, since there exist, through the defective septum which is hardly ever absent, paths of outlet for the blood into the left half of the heart, which may- at first direct both circulations. In older chil dren the heart region is arched forward, the apex-beat made more diffuse and the cardiac dulness reaches disproportionately far beyond the right edge of the sternum.
Auscultation in most cases gives a systolic murmur over the ostium or the trunk of the pulmonary artery, with weakening of the second sound at the pulmonary area. For ostium stenosis, if it lasts a long time, is always accompanied by abnormal circulatory communications (defective septum, patulous ductus) so that the latter are to be consid ered in making the diagnosis.
The point of maximum intensity of the murmur is the left edge of the sternum between the insertions of the second and third costal car tilages, when the stenosis is combined with defective septum. Moving toward the right the murmur always grows rapidly less intense, but is loudest to the left of the sternum. As a rule the first heart sound at the pulmonary area is indistinctly audible or only incompletely sug gested; only rarely does the murmur wholly take its place. Stenoses of the pulmonary artery have been described without murmurs and with cardiac hypertrophy and others with murmurs and without hyper trophy. Sometimes murmurs first appear near the end of life, without having been heard during many years; so, too, the disappearance of formerly perceptible murmurs has been observed. Tbe absence of
murmurs is explained in many cases, if the stenosis is high-grade, by the blood flowing into the left half of the heart through an open inter ventricular septum. When defective septum and pulmonary stenosis are combined, the murmur is often transmitted through the perforation in the septum to the aorta and into the carotids.
In childhood much more than in later life the observation of the quality of the second sound at the puhnonary area may lead to the cor rect diagnosis of pulmonary stenosis. With pure ostium stenosis of the pulmonary artery the second sound of the heart is always weakened, never accentuated, and if the children are small, it is never stronger than the first sound at the base of the heart. The smaller quantity of blood passing through the stenotic ostium of the pulmonary artery may cause, in diastole naturally, only a weak diastolic rebound against the semilunar valves, i.e., a weak second sound at the pulmonary area. The simultaneous presence of a large defect in the interventricular septum can, after the child has lived a long time. exert an accentuating influence upon the second sound, since the left ventricle, under great pressure, aids in distributing blood to the pulmonary artery. Still, very- marked accentuation is not to be expected from this combination. It is different with the simultaneous persistence of the ductus arteriosus, when the valves of the pulmonary artery have not suffered any damage in their ability to move and to oscillate. In later life, besides, as a re sult of the always increasing hypertrophy of the right side of the heart, an abnormally large quantity of blood may be driven into the pul monary artery so that, contrary to all hypotheses, an accentuation of the second sound appears. Thus the quality of the second sound at the pulmonary area offers certain aid in diagnosis in early childhood only.
With pure conus stenosis also the second sound must be low. The second sound may be abnormally loud and may- wholly- obliterate the picture of pulmonary stenosis if conus stenosis is combined with patu Ions ductus or if ostium or conus stenosis is associated with dilatation of the pulmonary artery.