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 dilated 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.





More

;