Hayden says that it is exceptional to have a purring thrill with simple mitral reflux. I have never found it except in those cases where left ventricular dilatation greatly exceeded the hypertrophy.
Percussion.—Percussion reveals an increase in the area of cardiac dulness, especially laterally; it extends both to the left and right of the normal line, as well as downward. The area of superficial as well as deep-seated dulness will be increased laterally and downward.
Auscultation.—Mitral insufficiency is attended by a systolic murmur which either completely or partially replaces the first sound of the heart. The quality of the murmur is variable, and not in itself as distinctive as that of mitral stenosis. It is usually a soft and blowing bellows murmur; sometimes, toward its end, the murmur will assume a distinctly musical character.
While the first sound of the heart may be heard distinctly in the early stages of mitral reflux, later the murmur in nearly all cases takes the place of the heart-sounds. Hence many English writers rightly denominate this murmur as post-systolic rather than systolic in its nascent stages. It is heard with its maximum intensity at the apex-beat. Its area of diffusion is to the left on a line corresponding to the apex-beat. It is audible at or near the inferior angle of the left scapula. It can be heard between the lower border of the fifth and the upper border of the eighth vertebra, at the left of the spine, with nearly the same intensity as at the apex. The murmur may be absent from the latter situation until cardiac hypertrophy is developed.
The second sound of the heart over the pulmonary valves is accentuated, while below the junction of the third rib with the sternum on the left side both heart-sounds are feeble. Skoda first drew attention to exaggeration of the second pulmonary arterial sound as a positive and unerring indication of mitral regurgitation.
An intensified pulmonary second sound requires a strong right ventricle and an intact tricuspid valve, and is not always present. In general terms, the area of diffusion of a mitral regurgitant murmur is toward the left of the apex-beat. Whatever may be its character, the murmur is generally loudest at its commencement. A loud systolic murmur at the apex, and not heard at the back, is probably not produced by mitral reflux.
As at the aortic orifice, so at the mitral, stenosis and regurgitation are apt to occur in the same individual, giving rise to a combined presystolic and systolic murmur, which is a continuous murmur that begins shortly after the second sound of the heart and often continues until the second sound commences. The two sounds, although mingling to form one murmur, can, in the majority of cases, be readily distinguished from each other, for the point of maximum intensity and the very limited area of diffusion of a presystolic murmur readily distinguish it from a mitral systolic which is audible in the left scapular region. It is important to recognize the existence of both these murmurs in estimating the prognosis in any case. Guttman mentions a case where five distinct murmurs were combined and yet clearly distinguishable.
DIFFERENTIAL DIAGNOSIS.—It is usually not difficult to recognize mitral regurgitation. The seat and rhythm of the murmur and its area of diffusion are sufficient to distinguish it from other cardiac murmurs. The character of the pulse, the symptoms referable to the right heart, and the pulmonary complications will also assist in its diagnosis.
It may, however, be mistaken for aortic obstruction, since both give rise to a systolic murmur, for tricuspid regurgitation, for fibroid disease of the heart, and for roughening of the ventricular surface of the mitral valve or of the ventricular wall near the aortic orifice.
The diagnosis between mitral regurgitation and aortic stenosis has already been given (see [page 657]).