Overview of mitral valve disease
A mitral valve can be diseased in two ways: stenosis or regurgitation.
Mitral valve stenosis
Mitral valve stenosis is a condition where the mitral valve fails to open completely and limits blood flow to the body. The most common cause of mitral stenosis is rheumatic fever, but there are other causes, such as radiation therapy and valve degeneration with severe calcium deposits that obstruct the valve.
Mitral valve regurgitation
Mitral valve regurgitation, also known as mitral insufficiency or incompetence, is a heart condition where the mitral valve fails to close completely and allows blood to flow back into the left atrium. This heart defect can result from primary valve regurgitation. It can also result from a diseased left ventricle (a dilated heart) that pulls the valve leaflets apart and is known as secondary (or functional) mitral valve regurgitation.
Primary valve regurgitation is most often caused by degenerative diseases, such as Fibroelastic Deficiency or Barlow’s disease. Other causes include Marfan’s syndrome, endocarditis, congenital diseases and inflammatory conditions, such as rheumatic fever and lupus erythematosus.
Secondary—or functional—mitral regurgitation is caused by ventricle disease, including dilated cardiomyopathy, myocardial infarction with ischemic cardiomyopathy, hypertrophic cardiomyopathy, sarcoidosis and endomyocardial fibrosis.
Mitral valve disease symptoms
Mitral valve disease symptoms can vary and, at times, be confused with the regular process of aging. Some patients have minimal symptoms, but mitral valve disease is progressive and will eventually cause the heart to fail if left untreated.
If left untreated, mitral valve disease can result in heart failure, atrial fibrillation and pulmonary hypertension—all of which further reduce the patient’s functional capacity and ability to carry out activities of daily living.
Mitral valve disease symptoms include:
- Shortness of breath
- Irregular heartbeat
- Swollen ankles or feet
- Difficulty lying flat, needing multiple pillows or to sit up
Possible complications of mitral valve surgery
As in every procedure, there are risks associated with mitral valve surgery
Possible mitral valve surgery risks include:
- A leak between the new valve and the native tissue
- Injury to the conduction system of the heart, possibly needing a pacemaker
- Limiting blood flow to the heart by inadvertent blockage of the coronary arteries
- Bleeding requiring blood transfusion
Diagnosing mitral valve disease
The most important test to help diagnose mitral valve disease is an echocardiogram, which provides information about the extent of stenosis or regurgitation alongside the anatomic reason for the valve dysfunction.
Diagnostic tests that help detect mitral valve disease include:
- Chest X-ray
- Cardiac catheterization to look at the pressures in the lung and the blood vessels to the heart
- MRI to assess the valve and ventricular function
- CT scan to look at calcification
Mitral valve disease treatment
Mitral valve disease treatment depends on the severity of the mitral valve disease and symptoms. Treatment decisions are made by a team of specialists, including a cardiologist, cardiac surgeon and primary care physician.
Mitral stenosis treatment
Mitral stenosis treatment consists primarily of percutaneous balloon dilation of the valve or surgical valve replacement. Balloon dilatation is performed by threading a balloon from the groin into the heart and across the valve. Only patients with favorable valve anatomy, with an absence of calcium on the valve, are eligible for balloon dilation. Many options for percutaneous valve replacement are under development, but valve replacement currently involves open-heart surgery. Current artificial valves fall under two categories: tissue and mechanical. Tissue valves are derived from pigs or cows, and mechanical valves are made from pyrolytic carbon. Tissue valves need to be replaced after eight to 10 years, and mechanical valves require blood thinners for life following mitral valve surgery.
Mitral regurgitation treatment
Managing mitral regurgitation requires a combination of beta blockers, vasodilators and diuretics, as indicated. Unfortunately, severe mitral regurgitation is progressive and leads to ventricular dysfunction and heart failure unless intervened upon. Surgery is the treatment of choice. The vast majority of valves can be repaired, but badly diseased valves must be replaced. In patients with advanced heart failure, surgical treatment may not be an option, so heart failure treatments (a ventricular assist device or transplantation) can be considered. Another option for high-risk patients is a percutaneous device called the MitraClip™. If the mitral valve is badly damaged or calcified and cannot be repaired, a tissue or metal valve can replace it. Tissue valves generally last 10 years before being replaced. Mechanical valves can last a lifetime but require life-long use of a blood thinner (Coumadin) after surgery.
After an evaluation by the heart team and undergoing appropriate testing, you will meet our nurse educator who will give you a booklet and talk to you about the stepwise progression you will be expected to make through your heart surgery. Your medications will be discussed, and you may be asked to stop certain medications up to one week before the mitral valve procedure. It is important to plan ahead and make arrangements for transportation to and from the hospital and also help at home after the mitral valve procedure.
After arriving at the admitting area, mitral valve surgery patients are seen by the operating room team, including the anesthesia team who start an intravenous line to give medications. The family will be asked to stay in the waiting area until the mitral valve procedure is complete. Heart patients are placed on a ventilator for the duration of the surgery and a few hours after surgery. The mitral valve surgery can last several hours depending on the complexity and on the findings in the operating room. After completion of the mitral valve surgery, the heart surgeon will speak to the family about the procedure and answer any questions, including recover time from heart surgery.
Patients who undergo mitral valve surgery are usually in the hospital for five to seven days. The stay in the ICU is usually for the first 24 hours, followed by a transfer to a monitored bed on the floor. Most patients begin walking the day after heart surgery. We have a large team of people who specialize in the various aspects of recovery to work with you, teach you and instruct you on the best practices for your recovery. Follow-up visits in the clinic are at two weeks and four weeks after mitral valve surgery.