The mitral valve is a two flapped valve which connects the two left chambers of the heart, the left atrium and the left ventricle and in it’s normal operation prevents the backflow of blood from the ventricle into the atrium. In the typical cardiac cycle during left ventricular diastole i.e. when the left ventricle is relaxing, the mitral valve opens allowing for blood to flow from the left atrium to the left ventricle. The proper direction of blood flow is regulated by a pressure difference mechanism in the two chambers.
When the person is affected by Mitral Stenosis the valve malfunctions and fails to open properly. Thus leading to an increased pressure in the left atrium as higher pressure is needed now to transport the same amount of blood to the left ventricle.
The main cause for mitral stenosis is heart disease which occurs subsequent to a bout of rheumatic fever. Rheumatic Heart disease is also a very common cause for Mitral Stenosis. Problems with the valve appear only after a time period of roughly 5-10 years has elapsed since the rheumatic fever. Certain other causes are also known to cause mitral stenosis, though very rarely. Calcium deposits around the mitral valve, radiation treatment to the chest, and some types of medication number among these other causes.
The onset of symptoms usually occurs between the ages of 20 to 50. In some cases there may not be any noticeable symptoms at all. Symptoms usually begin with atrial fibrillation or an irregular rate of heart beat. The Following symptoms are usually seen:
- Cough, sometimes with blood also known as hemoptysis
- Breathing Difficulty especially after intense physical activity or when lying flat or upon suddenly waking up
- Frequent respiratory infections such as bronchitis
- Palpitations or the sensation of feeling ones heartbeats
- Swelling of feet and ankles.
- Chest discomfort may occur rarely such that it increases with physical activity and decreases upon taking rest
Diagnosis is done first by conducting a physical test in which the doctor listens to the patients’ heartbeat through a stethoscope. An abnormal sound usually manifesting in the form of a distinctive murmur or a snap is heard. The defining murmur is heard during the resting phase of the cardiac cycle and this sound becomes louder just before the contraction begins in the heart.
Once the above symptoms have been observed the doctor may prescribe the following tests to check for obstruction of the valve or any sort of swelling in the heart:
- Chest X ray
- Cardiac Catheterization
- Doppler Ultrasound
- MRI of the heart
Treatment procedures for Mitral Stenosis include medication, surgical options like valve replacement or valvuloplasty. It depends on the severity of the symptoms and the condition of the heart and lungs. Medication serves the purpose of merely relieving the symptoms and do not contribute to repairing the valve in any way. Diuretics, nitrates, betablockers etc are the commonly used medication. Anti-coagulants are also used.
In case of severe symptoms a surgical procedure is inevitable and the valve needs to be replaced. An alternative to surgery is valvuloplasty, a procedure involving the use of a balloon at the end of a catheter which is inflated and the valve is thus widened. The possible complications include blood clots in the brain and other areas, heart failure, pulmonary edema or fluid accumulation in the lungs and pulmonary hypertension. Mitral Stenosis may be prevented at an early stage by consulting a doctor at the slightest hint of rheumatic fever as it is the primary cause.