When the diagnosis of congenital pulmonary stenosis is made with certainty from the other symptoms, then with regard to the circum stances noted above. the following further rules of differential diagnosis may be deduced: 1. Abnormally neak second sound and absence of transmission into the veins of the neck lead to the presumption of pure stenoses or those combined with patulous foramen ovale only.
2. Clear but not accentuated second sound, with or without trans mission of the murmurs into the veins of the neck, points to the simul taneous presence of an interventricular communication.
3. Marked accentuation of the second sound, with distinct trans mission of murmurs into the carotids and subclavians, speaks almost with certainty for a patulous ductus arteriosus at the same time. This diagnosis becomes more certain if the murmur, as it reaches the neck, becomes vibrating in character, which is also observed in the veins of the neck, and if there are at the same time intimations of hypertrophy of the left side of the heart and palpable vibration of the arch of the aorta in the neck.
Subjective most prominent subjective symptoms are dyspnrea. attacks of suffocation, a tendency to fainting and ver tigo. Very many of these children show the highest grade of cyanosis, which is increased to a very dark blue color by shrieking and crying, and by rapid movements of the body with the occurrence of the suffo cative attacks. More than in the other congenital anomalies of the heart, all the causes leading to cyanosis (see p. 472) concur here. Very frequently such children are born apparently (lead and deeply cyanotic, but recover. If the action of tbe left ventricle is sufficiently strong, considerable good health may exist for a long time, in spite of the cyanosis, although such children are easily chilled, stand mental and bodily exertion badly and are in general very susceptible. Many children with pulmonary stenosis die from pulmonary and exanthema tons affections, but a large number of individuals live to reach later life, to 50 years or more. When loss of compensation appears, stasis results in the large veins of the body, with relative tricuspid insuffi ciency; the patients then die from dropsy.
In no congenital heart anomaly does clubbing of the fingers appear so early and so completely as in pulmonary stenosis.
(b) Congenital Stenosis of the Aorta Congenital stenoses at the origin of the aorta are rarer than those at the beginning of the pulmonary artery and are divided anatomically like the latter into ostium and corms stenosis. Just as in pulmonary stenosis the valves may become adherent, forming a diaphragm with a central perforation, complete obliteration of the initial portion of the aorta also occurs, in which case, if the child lives (extra utero), the pulmonary- artery is dilated vicariously as a rule, the interventricular septum is widely patulous and the circulation of the body is kept up with difficulty through the open ductus.
A general narrowness of the aorta (hypoplasia of the aortic systetn) and congenital stenoses of this vessel beyond its origin are to be dif ferentiated from the stenoses of the initial portion of the aorta.
Of especial importance is the so-called isthmus stenosis at the point of entrance of the ductus arteriosus. According to Theremin and Bonnet two anatomical types of isthmus stenosis must be differentiated. The first, which never leads to complete obliteration, is the result of arrested development of the isthmus aortic, i.e., of that portion which at an early period of faital life forms the connection between that part of the aorta which is to supply the upper half of the body and the descending aorta which branches off from the pulmonary artery. In this form the ductus RotaIli is usually patulous. This stenosis affects that portion of the aortic arch between the left subclavian artery and the ductus Botalli.
The other, more frequent form is situated constantly opposite the insertion of the ductus ligamentum arteriosum and, as Skoda has taught, is clue to contraction of that part of the wall of the arch of the aorta lying next to the ductus, since this portion must be supposed to be structurally like the wall of the ductus Botalli.
Congenital hypoplasia of the aortic system is characterized anatomi cally by abnormally thin walls, abnormal slenderness and dilatability of the aorta and its main branches. 'rhe aorta itself is frequently no wider than the normal carotid (see Fig. 111. A). The left ventricle is sometimes abnormally small, at other times considerably hypertrophied. The patients remain amemic, small and weakly-, and show delayed sexual development.