What happens in the heart
Normally, the mitral valve leaflets open wide, allowing blood to flow freely from the atrium to the ventricle. With stenosis, the valves thicken, fuse at the edges, and the subvalvular structures are shortened, and the opening turns into a narrow gap. To push blood through, the atrium has to work with increased pressure, it stretches and loses the ability to contract harmoniously - hence the frequent development of atrial fibrillation. Stagnation of blood in the pulmonary vessels causes shortness of breath, and over time the pressure in the pulmonary artery increases and the right side of the heart suffers.
- Fusion and thickening of valve leaflets
- Increased pressure in the left atrium
- Atrial enlargement and risk of atrial fibrillation
- Congestion in the blood vessels of the lungs
- Pulmonary hypertension and right side overload
- Risk of blood clots in the atrium
Reasons
The leading cause is chronic rheumatic heart disease, which develops after acute rheumatic fever. It occurs as a complication of streptococcal sore throat, if it has not been treated with an antibiotic, and damages the valves through immune mechanisms. It often takes 10–20 years between the experience of fever and the appearance of complaints, so many patients do not remember the illness in childhood. Much less common are congenital narrowing, severe calcification of the valve ring in the elderly, and rare systemic diseases.
- Past acute rheumatic fever
- Untreated streptococcal sore throat in childhood
- Calcification of the valve ring in old age
- Congenital mitral stenosis
- Systemic connective tissue diseases
- Effects of radiation therapy on the chest area
Symptoms
The first and main symptom is shortness of breath: first with significant exertion, then with normal walking, and in severe cases - in a lying position, which is why a person sleeps on high pillows. Also characteristic are a dry cough, fatigue, palpitations and poor tolerance to pregnancy, when the load on the heart increases sharply. Sometimes the defect first manifests itself as an attack of atrial fibrillation or embolism - a sudden blockage of a vessel by a blood clot that has formed in the distended atrium.
- Shortness of breath on exertion, then at rest
- Nocturnal attacks of suffocation, sleeping on high pillows
- Dry cough, sometimes hemoptysis
- Weakness and fatigue
- Attacks of irregular heartbeat
- Swelling of the legs and heaviness in the right hypochondrium in the later stages
Diagnostics
When listening to the heart, the doctor notes a characteristic murmur and special tones, which already allows one to suspect a defect. Echocardiography confirms the diagnosis: it shows the structure and mobility of the valves, the area of the opening, the size of the atrium and the pressure in the pulmonary artery. Based on these data, the degree of stenosis and the suitability of the valve for gentle intervention are determined. An ECG reveals atrial overload and atrial fibrillation, an X-ray reveals congestion in the lungs. When planning the operation, a transesophageal examination is additionally performed to exclude a thrombus in the atrium.
- Auscultation of the heart
- Echocardiography with orifice area assessment
- ECG and Holter monitoring
- Chest X-ray
- Transesophageal echocardiography before surgery
- Evaluation of kidney function, liver function and blood tests
Treatment
If the narrowing is slight and there are no complaints, observation with periodic echocardiography is sufficient. Medicines do not widen the valve, but they reduce symptoms: they slow down the rhythm, remove excess fluid, and control arrhythmia. In case of atrial fibrillation against the background of mitral stenosis, prevention of thromboembolism with an anticoagulant, which is selected by the doctor, is mandatory - the risk of stroke is especially high here. In case of severe narrowing with symptoms, a balloon commissurotomy through the vessel or open surgery with plastic surgery or valve replacement is performed. Prevention of recurrent streptococcal infections is also important.
- Observation and control echocardiography for mild stenosis
- Drugs to slow the rhythm and reduce congestion
- Anticoagulant for atrial fibrillation as prescribed by a doctor
- Balloon mitral commissurotomy
- Valve surgery or replacement
- Prevention of rheumatic fever
- Timely treatment of sore throat with antibiotics as prescribed
