Mitral and tricuspid insufficiency both produce a systolic murmur, but a mitral regurgitant murmur has its maximum of intensity at the apex, and is conveyed toward the left axillary and scapular regions, while the maximum intensity of a tricuspid regurgitant murmur is to the right of the base of the xiphoid cartilage, and it is transmitted upward and to the right: the area of transmission establishes the diagnosis.
Pulmonary symptoms are prominent in mitral reflux, and absent in tricuspid regurgitation. The pulmonary second sound is markedly enfeebled in tricuspid regurgitation, and markedly intensified in mitral regurgitation.
Fibroid disease of the heart may produce a systolic apex murmur, but it is an exceedingly rare disease, a pathological curiosity.20
20 In the Pathological Transactions (1874, vol. xxv. p. 64) Fagge records a few cases, and mentions that perhaps one positive indication of fibroid disease of the heart, rather than of a valvular lesion, may be found in its resisting treatment with greater obstinacy.
Roughening of the ventricular wall gives rise to a murmur which has its maximum intensity at the base of the heart, and is transmitted along the aortic arch and into the vessels which spring from it in the thorax.
The vibration of an irregular chordæ tendineæ stretched across the aortic orifice, its extremities being inserted into opposite walls of the ventricle, may produce a systolic musical murmur, but the line of its transmission will correspond to that of an aortic obstruction. A systolic mitral murmur due to the sudden rupture of one or a number of the valve-flaps, of the papillary muscles or tendons, is accompanied by a loud systolic blowing murmur, which is immediately accompanied by all the urgent symptoms of acute pulmonary congestion.
Pulmonary Obstruction.
On account of the infrequency of disease of the pulmonic valves very little is known of the phenomena to which such diseases may give rise. In fact, they are so rare that there is no written history of their subjective symptoms; their diagnosis is only arrived at by exclusion, and they cannot be recognized except by the physical signs which attend them.
As has been already stated, endocarditis in the right heart is rare, except in intra-uterine life, and the various conditions of the aorta, atheroma, aortitis, etc., which I have mentioned in the etiology of aortic valvular disease have no analogues in the pulmonary vessels.
Usually, valvular disease of the right heart is the sequela of lesions in the left. It must be remembered, however, that the pulmonary artery may become atheromatous. I have already shown (see [p. 666]) how certain valvular diseases of the left heart may induce such a pathological condition. But even under such conditions disease of the pulmonary valves is rare. Balfour believes that constriction of the pulmonary artery may occur at various periods of intra-uterine life. As a rule, the pulmonary valves are subject to no lesions except congenital malformation.