Mitral Valve DiseaseHere is a basic understanding of mitral valve disease
Mitral valve disease can present at any age depending on the cause. A narrowed mitral valve can take many years to be symptomatic while a leaking mitral valve can present as an emergency. The mechanisms causing the abnormality dictate how early it needs to be treated as well as the type of treatment.
The mitral valve is a 2 leaflet structure that lies between the two left sided chambers the left atrium and the left ventricle. This valve allows blood to flow from the atrium to the ventricle but not backwards into the atrium. Structurally the valve has 2 leaflets with the one above (anterior) being larger (2/3rd) while the one below is smaller and one third the size. The functioning of the valve is akin to a parachute with leaflets being suspended by strings called chordae which are attached to the ventricle on one end and the mitral valve on the other end.
The mitral valve is simply like a parachute, with two leaflets suspended by chordae, that are attached to the papillary muscles at the base of the leftventricle.
Mitral Incompetence or Regurgitation
Often referred to as MR in short, this condition is secondary to the valve cusps not coapting or coming together to prevent blood from flowing back into the left atrium after its been ejected out. Most patients are diagnosed at an early stage when they present with either palpitations or breathlessness on exertion. Less commonly the presentation can be in an emergency when the valve leaks immediately following a heart attack. Untreated the ventricle progressively enlarges and heart failure sets in. The most common cause of a leaking mitral valve in India is rheumatic heart disease. Less common causes are degenerative mitral valve disease that can occur secondary to a variety of conditions ranging from congenital diseases affecting collagen to simply age causing degeneration. Infective endocarditis and heart attacks can also lead to a leaking mitral valve.
The valve orifice opening becomes progressively narrowed due to fusion of leaflets and calcification. The most common cause of mitral stenosis is rheumatic heart disease (RHD). RHD is caused secondary to untreated Group A Streptococcal sore throat. Antibodies produced against the bacteria cross react with the bodies own tissue particularly the joints and the heart. This results in scarring of the heart valves that fuse resulting in stenosis. RHD is more common in the developing world and antibiotic treatment of sore throat has vastly reduced the incidence of the disease. Progression is highly variable and in countries like India symptoms often develop in the early teens. Sudden deterioration can occur following pregnancy or atrial fibrillation. Surgery to replace the valve is often required as the disease advances. The most common symptoms are usually fatigue, shortness of breath on exercise, palpitations and breathlessness occurring in sleep (PND). If the heart loses its rhythm, blood could clot in the atria and embolize causing strokes.
Medical treatment of Mitral Valve Disease
When diagnosed early medication may have a role in managing mitral valve disease. Medication helps in delaying surgery in those diagnosed with a leaking mitral valve in particular. Its important to note that medication has a limited role and is of no benefit in advanced disease.
When should one choose surgery?
The decision to choose surgery for treating mitral valve disease is done in consult with your medical care team which should comprise of a heart surgeon and cardiologist. The recommendation is based on several factors including symptoms as well as various investigations such as an echocardiogram and angiogram. The ECHO will help assess the degree of stenosis or regurgitation, will show enlargement of the heart if any as well other coexistent anomalies. The angiogram will show this in addition to blocks in the vessels supplying the heart if any.
Surgical Mitral Valve Repair is an option for some leaking mitral valves particularly in degenerative mitral valve disease. Only your surgeon can decide whether he can repair. Its important to note that not all surgeons are competent in repairing the mitral valve.
Surgical MVR (Mitral Valve Replacement) is the gold standard for effective treatment of severe mitral valve disease. It has been proven to provide symptomatic relief and long term survival in adults. During the procedure the native valve is removed and replaced with an appropriately sized artificial valve. Surgical MVR is recommended in all adult patients who do not have other medical conditions that prevents them from undergoing the procedure.
Treatment options for Mitral Valve Disease
Three treatment options exist for surgical mitral valve replacement
- Traditional replacement: The breast bone is cut in full to access the heart and the aortic valve replaced
- Minimally Invasive Cardiac Surgical Technique that allow for the valve to be replaced via a small incision made on the side of the chest on the right side. The advantage is rapid recovery and is fast becoming the standard operation
- Balloon Mitral Valvotomy (BMV) is performed in mitral stenosis where the valve leaflets are fused with an intact subvalvar apparatus. Its usually performed by your cardiologist with the surgeon as backup in case an emergency arises. The valve can occasionally tear resulting in a severe leak requiring it to be replaced.
Mitral Valve Incompetence in General Population
RHD as a cause of Mitral Stenosis
Patients who develop a severely leaking mitral valve(MR) after a heart attack
Need a mitral valve repaired/replaced? Read more here
Diagnosing Mitral Valve Disaese
- Clinical Examinations: Your heart surgeon or cardiologist can hear abnormal heart sounds called a murmur on examining your heart with a stethescope
- ECG or Electrocardiogram
- Chest Xray
- Echocardiogram: This is the most frequently performed and the most reliable investigation to diagnose the condition as well as to estimate the severity of the disease. Often no other tests are required once an ECHO is done
Symptoms of Mitral Valve Disease
- Difficulty in breathing often at rest or during sleep (PND)
- Difficulty exercising due to shortness of breath
- Irregular heart beats or Atrial fibrillation
- Heart Failure