In the course of severe pulmonary affections and the infectious diseases, even in the earliest periods of life, systolic murmurs may arise in the pre-agonic stage, which are due, not to changes produced by endocarditis, but to relative dilatation insufficiency of the atrioven tricular valves, or to paralysis of the heart, but these murmurs may be mistaken for accidental murmurs.
Arterial urtnurs.—Small children during the first 2 to 3 years have no peculiar sounds in the arteries of the neck. Such sounds are found in older children, but may be changed into murmurs by- moderate pressure with the stethoscope. The occurrence of murmurs in the ar teries of the neck is only of value in diagnosis in childhood if the mur murs are transmitted from the heart and are recognizable as such, a condition which is observed very frequently in congenital heart lesions.
Venous Murinurs.—Venous murmurs are very frequent in all periods of childhood. Tbey can lie heard over the chest, on both sides of the sternum, when they occur in the innominate veins. Even more frequent are murmurs in the VC] 11,3 of the neck, with or without murmurs in thc innornituite veins. Older children with anaunic heart murmurs always show murmurs in the veins of the neck, while children with true heart diseases often have such murmurs also. In the combination of cardiac and venous murmurs, it should be the rule that endocardial murmurs localized at the pulmonary area are to be considered acci dental, while a loud cardiac murmur at the apex, without any murmur in the pulmonary area, shows. enclocarditis almost without exception, in spite of the simultaneous presence of a venous hum. Murmurs in the veins of the neck do not occur in healthy children if one is suffi ciently careful, during auscultation, not to extend the neck too far or to press too hard with the stethoscope.
Venous murmurs which are especially limited to the right half of the chest occur in the right innorninate vein, which is very commonly the seat of a murmur in anamic, particularly tuberculous children (in fants also); the left innotninate vein shows no auscultatory anomalies.
Possibly this venous murmur arises in the superior vena cave and is transmitted into the right innominate vein, the direct prolongation of the vena cava, while the left innominate vein, branching off at an ttngle from the superior vena cava, remains untouched by the murmur. The eases of unexplained systolic heart murmurs, noted by Gregor and Madan, are to be regarded as innotninate murtnurs. They very fre quently give the impression of a systolic murmur of long duration, since they are decidedly increased when the aorta fills with systole; whether rhythmical compression of the right innominate and vena cava, due to the filling of the aorta, occurs here or not, may be left undecided.
The venous murmur heard by Eustace Smith above the manubrium sterni depends, according to i,Irnith, upon compression of the veins by bronchial glands. When the child's head is extended far backward a venous murmur is heard with the stethoscope placed over the mann brium sterni; if the child's head is moved forward the murmur becomes weaker; when it reaches its normal position the murmur disappears. The occurrence of this venous murmur with hyperplasia of the bron chial glands is dependent upon forward movement of the trachea as the result of overextension of the neck, so that the glands bing at the bifurcation of the trachea are shoved forward and pressed against the innominate veins. Hochsinger notes that this murmur is very fre quent. in infancy especially, and also iu children in whom there is no suspicion of enlargement of the bronchial glands. Flochnger has found this murmur strildngly frequent in children with hyperplasia of the thymus gland, and with dulness noted over the manuMium sterni, dependent upon the presence of this gland. It always arises from pressure upon the innominate veins, whether hyperplasia of the bron chial glands or thymus gland exits or not. ,