In mitral insufficiency, blood from the left ventricle flows back into the left atrium. In mitral stenosis, blood flow is obstructed from the left atrium to the left ventricle. In both cases, the result is an enlarged left atrium.
Mitral insufficiency, or stenosis, most often is secondary to childhood rheumatic fever, MI, or infective endocarditis in which vegetations on the heart valves cause stenosis. Severe left-sided heart failure, or mitral valve prolapse, a falling or dropping down of the valve tissue, may occur.
FIGURE. Gross pathology showing mitral stenosis. The left atrium has been opened to show thickened mitral valve leaflets from above. (Centers for Disease Control and Prevention. Dr. Edwin P. Ewing, Jr. Creation date 1973.)
Signs and Symptoms
In both conditions, there may be orthopnea, dyspnea, fatigue, palpitations, peripheral edema, atrial fibrillation, pulmonary hypertension, and distention of the jugular veins. Abnormal heart sounds can be identified during auscultation.
In both conditions, echocardiography and electrocardiography may establish the diagnosis. Cardiac catheterization may be necessary to fully identify the severity of the problem. The results of auscultation will be specific to each condition.
The treatment approach depends on the severity of the symptoms. Generally, the treatment of choice is surgical replacement with an artificial valve. Balloon valvuloplasty (also called percutaneous balloon valvuloplasty), a surgical procedure to open a narrowed heart valve, may be performed.
No significant complementary therapy is indicated.
If surgery is necessary, prepare clients both preoperatively and postoperatively. A description of balloon valvuloplasty might include the following information: A thin tube or balloontipped catheter is inserted through the skin in the groin area into a blood vessel. The tube is threaded up to the opening of the narrowed heart valve where the balloon is inflated to stretch the valve open. The procedure is performed in a cardiac catheterization laboratory and takes about 4 hours.
The prognosis is good. The disease usually is not progressive, and many clients live a long time without surgery. Both mitral insufficiency and stenosis can lead to right ventricular hypertrophy and right ventricular failure.
There is no known prevention for mitral insufficiency/stenosis other than the prevention of rheumatic fever, infections, and MI.