History
The history of mitral valve stenosis is essentially limited to the new surgical interventional methods such as balloon dilatation.
Causes of mitral valve stenosis
The main or leading symptom of mitral valve stenosis or mitral insufficiency is shortness of breath (medical term: dyspnea). The shortness of breath is caused by the backflow of blood into the lungs. This backflow into the lungs causes the liquid part of the blood to be pressed out into the lung tissue, thus making it difficult for oxygen to be transported into the blood.
The reduced oxygen transport leads to difficult breathing or shortness of breath. In most cases, shortness of breath only occurs during exertion, as the heart works more intensively in this area and the congestion in front of the left chamber is increased. If the constriction is particularly severe, shortness of breath can also occur at rest.
A further consequence of the congestion in the lungs can be attacks of haemoptysis. Here, the congestion in the lungs increases and the solid components of the blood (red blood corpuscles) also escape into the pulmonary tract, causing the sputum to turn red. The dilatation of the left atrium can lead to the so-called atrial fibrillation.
In atrial fibrillation, the blood flow (hemodynamics) is disturbed and blood clots can form, which can spread to the body and cause further clinical symptoms. Right heart strain manifests itself in a blood backlog in front of the right heart. This congestion can lead to an enlargement of the liver, and can also lead to water accumulation in the legs (leg edema).
Due to the reduced ejection volume (with reduced filling of the left ventricle), some patients suffer from peripheral cyanosis (blue coloration of the skin). This is caused by the increased oxygen depletion from the blood. In most cases, mitral valve stenosis is diagnosed after the patient interview (anamnesis), in which the patient presents his symptoms.
In the case of mitral valve stenosis, the patient may notice a reduced ability to cope with everyday situations and/or symptoms from the above paragraph. If mitral valve stenosis is suspected, the physician will want to confirm his or her thought process with a physical examination. This is usually done first with the stethoscope.
During the examination, the physician would particularly hear abnormal heart murmurs on the left half of the chest in the fourth intercostal space (medically: 4th intercostal space). Additional diagnostics would be the writing of an ECG ́s, in which the doctor can record the electrical activity of the heart. Here the doctor could detect signs of atrial fibrillation (restless baseline in the ECG) or signs of cardiac stress.
The doctor may also use imaging techniques to support his diagnosis. The echocardiogram allows the physician to take an ultrasound image of the narrowed mitral valve to determine the degree of valve narrowing. Since the echocardiogram can also record the blood flow over the valve, this examination is considered crucial in the diagnosis of mitral valve stenosis.
Another examination option using ultrasound is the so-called swallow echo. Here the anatomical proximity of the heart to the esophagus is exploited by swallowing the ultrasound probe by the patient. In this way, the functioning of the heart valves can be assessed and mitral valve stenosis diagnosed.
Other imaging techniques such as X-rays, computed tomography and MRI can provide information about the heart load and changes in heart structure and valve architecture. However, these methods are more expensive than echocardiography or have a high radiation exposure. The therapy of mitral valve stenosis can be either conservative or surgical.
The conservative therapy of mitral valve stenosis is usually a drug therapy of the volume load on the heart caused by the defective mitral valve. The task of the medication is to reduce the volume of blood that accumulates in front of the defective valve (heart valve) in order to relieve the heart. In general, the work of the heart (heart rate X beat volume) should be reduced, as an increase in heart work increases the symptoms of mitral valve stenosis/mitral valve insufficiency.
Means of choosing a therapy for mitral valve stenosis in this case diuretics (drainers). Dehydrators slightly reduce the blood volume and thus also reduce the stroke volume. If pulmonary hypertension is present in addition to the symptoms, vasodilators can also be used in therapy to lower blood pressure.If other severe symptoms of mitral valve stenosis occur, they must also be treated with medication.
In the case of atrial fibrillation, for example, blood thinners and beta blockers must be used to reduce the risk of embolism and the heart rate. Sometimes a conservative therapy of mitral valve stenosis does not achieve a sufficient therapeutic result. The indication for surgical therapy depends on the patient’s symptoms and heart function.
If the heart function is impaired, e.g. if blood ejection is below 60%, surgical treatment of mitral valve stenosis is possible. Surgical therapy includes several methods for restoring or dilating the mitral valve, for example, by narrowing it. Balloon dilatation (percutaneous balloon mitral valvuloplasty) is a method in which a small balloon is inserted into the area of the mitral valve with a catheter via the groin.
This procedure is particularly gentle on the patient, as the chest does not have to be opened. By inflating the balloon, the narrowed mitral valve is widened, thus increasing the blood flow between the left atrium and chamber. In addition, a so-called commisurotomy can be performed, in which the calcified valve tissue is removed and a functional valve can be created.
Valve reconstruction is often performed on the insufficient mitral valve and has a lower post-operative mortality rate compared to valve replacement. If these surgical procedures are not sufficient or cannot be performed, an artificial valve can be inserted. This valve can be artificial or can be derived from a biological preparation (pig, human). Artificial heart valves must be treated with a long-term therapy of blood thinners and aggregation inhibitors.
