Mitral Insufficiency: Mitral Regurgitation
Categories:
Uncategorized
Sources:
Disturbances Of The Heart
This is the most frequent form of valvular disease of the heart, and
is due to a shortening or thickening of the valves, or to some
adhesion which does not permit the valve, to close properly, and the
blood consequently regurgitates from the left ventricle into the
left auricle during the contraction of the ventricle. Such
regurgitation may occur without valvular disease if for any reason
the left ventricle becomes dil
ted sufficiently to cause the valve
to be insufficient. Such a dilatation can generally be cured by rest
and treatment. As with mitral stenosis, the most frequent causes are
rheumatism and chorea, with the occasional other causes as
previously enumerated.
The characteristic murmur of this lesion is a systolic blow,
accentuated at the apex, transmitted to the left of the thorax,
generally heard in the back, near the lower end of the scapula, and
transmitted upward over the precordia.
Of all cardiac lesions, this is the safest one to have. Sudden death
is unusual, the compensation of the heart seems to be most readily
maintained, and the patient is not so greatly dangered by
overexertion or by inflammations in the lungs. As in mitral
stenosis, any increase in blood pressure--whether the normal
increase after the age of 40, any continued earlier high tension, or
increase from occupation or exercise--is serious as causing the left
ventricle to act more strenuously, so that more blood is forced back
into the left auricle, the lungs become congested, and the right
ventricle, sooner or later, becomes incompetent.
When compensation fails with these patients, the first sign is
pendent edema of the feet, ankles and legs; subsequently, if there
is progressive failure of compensation, the usual symptoms occur.
The treatment is principally rest and digitalis, and the recovery of
compensation is often almost phenomenal. Patients with this lesion
are likely to be children and young adults, and the heart muscle
readily responds as a rule to the treatment inaugurated. Later, in
these patients, or if the lesion occurs in older patients, the
return to compensation does not occur so readily. If the condition
is developed from a myocarditis or from fatty degeneration of the
heart, it may be impossible to cause the left ventricle to improve
so much as to overcome this relative dilatation or relative
insufficiency of the valve. If the dilatation of the left ventricle
is due to some poisoning such as nicotin, with proper treatment--
stopping the use of tobacco, administration of digitalis, and rest--
the heart muscle will generally recover and the valve again properly
close.