In the diagnosis from chronic endoearditis of the mitral valve, stress is to be laid upon the absence or weakening of this systolic mur mur at the apex, upon the audibility of the first heart sound under the murmur, and upon the slight increase in the size of the cardiac muscle.
If the child lives a long time, hypertrophy of the tight side of the heart always results, which in pure cases always remains within moder ate limits.
More frequently than all other congenital heart anomalies, septum defects are associated with other disturbances of development, hypo spadias, epispadias, cleft diaphragm, spina bifida, meningocele, etc. The lesions are well borne for a long time; death follows u.sually in later life, as the result of endoearditie valvular insufficiency. Some times a defective septum is a surprising accessory condition found at autopsy, even in old persons who have never complained of any cardiac symptoms.
(b) Defects of the Interauricular Septum Patulous foramen ovalc is frequently found at autopsy; according to Waldniann and Klob, in per cent. of autopsies. Afore rare are perforations in the lower portion of the interauricular septum. Defects in the interauricular septum are only of consequence if, because of other congenital or acquired heart affections, increased pressure occurs in the left ventricle, causing an overflow of blood into the right auricle and stasis in the veins of tbe body. So, too, with increased pressure in the right auricle, resulting from stenosis of the pulmonary artery or 'ob struction to respiration in the lungs, severe circulatory disturbances, with the appearance of cyanosis, may occur if the foramen ovale remains patulous.
Clinically a presystolic or diastolic murmur should be heard over the centre of the sternum, hut this is seldom found with defects in the interauricular septum. Most eases run their course without anomalies in auscultation and the diagnosis is not made. In some cases systolic murmurs are also heard, but their relation to this anomaly is not at all determined.
The opinion of B. S. Schultze that the murmurs occurring here correspond to the diastole of the auricles is refuted by the production of pure systolic murmurs with defects of the interventricular septum.
Patulotts foramen ovale is an anomaly the diagnosis of which can hardly ever be made, but it is found at autopsy as an accessory condi tion at all ages. The occurrence of this defect can be suspected in young persons, if relatively slight affections of the respiratory and circulatory apparatus rapidly lead to cyanosis.
2, Stenoses of both Large Arterial Tranks (a) Stenoses of the Pulmonary Artery IP frequency and importance pulmonary. stenosis ranks first among the congenital heart lesions. It forms three-fifths of all congenital anomalies of the heart and since this affection, associated with defec tive septum, allows longer duration of life than all the other congenital heart lesions, its frequency in later life is apparently even much greater than all the other congenital heart affections (four-fifths of the eases).
The stenosis may affect either the ostium or the VCSSel trunk, in its extracardial course, or at its intracardial origin (conus stenosis). Complete obliteration (atresia) of the pulmonary artery is very rare; on the contrary, pre-arterial or corms stenosis is frequent.
Atresia and stenosis of the pulmonary artery are the most common congenital heart lesions, Peacock found 112 (84.44 per cent.) out of 189 cases collected. Vierordt reckoned all the cases hitherto reported at about 300. fp to 1877 Asmus collected 47 cases of colitis stenosis; in the past 20 years Vierordt collected 26, and recently Bennet, Buhl, Rauchfuss and Renvers have described new cases.
Sometimes the conus arteriosus becomes tied off at its origin from the ventricle as an accessory cardiac chamber, or there may be stenosis only at its apex, just below the ostium. The cause of stenosis of the ostium may be ketal endocarditis with adhesion. contraction and cal cification, or arrest of development from anomalous division of the truncus communis (Rokitansky). Complete adhesion of the semilunar valves into a diaphragm which cannot oscillate has also been observed. Stenoses occurring early in fcrtal life prevent the partition of the heart so that those portions of the septum which are formed under the aortic valves arc usually absent. On this account the point of origin of the aorta is frequently shoved somewhat out of place. The foramen ovale almost always, and the ductus arteriosus very frequently, persist. In this case it is the duty of the latter to distribute blood from the aorta to the branches of tbe pulmonary artery. The scanty amount of blood carried to the lungs in high-grade stcnoses is replaced by dilatation of the bronchial arteries vicariously; sometimes, also, of the cesophageal veins. The heart itself usually shows hypertrophy and dilatation of its right half. The action of the right ventricle may be arrested yrith com plete atresia of the ostium.