Valvular diseases

Located between the atria and ventricles, and the ventricles and great arteries, cardiac valves prevent the backflow of blood between the different chambers. Valve problems may be congenital, although valvular diseases in adults are typically acquired diseases, causing valvular stenosis, regurgitation, or both. When a valvular condition is mild, it does not impair the heart's pumping efficiency, nor does it cause any symptoms. Severe valvular diseases affect the heart's pumping efficiency, which leads to reduced physical performance, shortness of breath during activity, arrhythmia, and, finally, heart failure. A clinical examination and auscultation of the heart are important methods of detecting valvular problems.
 
Currently, valvular diseases and their degree can be diagnosed and the need for treatment and treatment options assessed by echocardiography. Cardiac catheterisation is an invasive procedure in which thin catheters are passed along arteries and veins to the heart to measure the pressure in the four chambers and the great arteries, and the pumping efficiency of the heart. However, cardiac catheterisation is losing its importance in the diagnosis of valvular diseases. Mild valvular problems do not require treatment. Severe valvular diseases that cause harmful symptoms or significantly impair the contracting force of the myocardium are surgically treated. Surgical procedures include valve replacement surgery in the case of valvular stenosis, and valve repair or replacement surgery in the case of valvular regurgitation. In exceptional situations, catheterisation is used in the treatment of valvular diseases.
 

Aortic valve stenosis

 
Aortic calcification is common in the elderly population. Stenosis resulting from aortic calcification is usually mild and does not require treatment. When an aortic valve has narrowed to ¼ of its normal size (usually 3.5 to 4 cm2), stenosis is considered severe and will start causing shortness of breath or chest pains or, occasionally, loss of consciousness during physical activity. Pumping blood through the narrowed valve overloads the left ventricle, causing its walls to thicken and eventually leading to heart failure. Physicians can detect aortic valve stenosis based on finding a murmur during auscultation. Diagnosis is confirmed by echocardiography. There is no medical treatment for aortic valve stenosis and the only option is valve replacement in open heart surgery. If the surgical operation presents a great risk, valve replacement is performed in a catheter-based operation.
 

Aortic valve regurgitation

 
In aortic valve regurgitation, the valve does not seal shut and some of the blood pumped by the left ventricle into the aorta flows back during diastole, causing the left ventricle to become overloaded and enlarged. When aortic regurgitation is severe, your left ventricle may need to work two or three times harder than normal. When prolonged, the overload eventually leads to left ventricle insufficiency. Aortic valve regurgitation is treated by valve replacement or repair in open heart surgery. Sometimes aortic valve regurgitation is caused by the pathological widening of the root of the aorta. In such cases, a tubular prosthesis is placed to repair the aortic root.
 

Mitral regurgitation

 
Mitral regurgitation is caused by damage to the mitral valve leaflets or tendons, or the mitral annulus, preventing the valve from sealing shut. If the valve does not seal shut, blood flows back from the ventricle to the left atrium. Incomplete sealing may also occur as a result of general or local left ventricle contraction insufficiency. In such cases, valvular regurgitation is caused by a defect in the left ventricle while the valve remains normal. Mitral regurgitation overloads the left ventricle, requiring it to work harder in order to pump blood. When prolonged, the overload eventually leads to left ventricle insufficiency causing shortness of breath during physical activity and reduced physical performance. Acute valvular regurgitation is usually caused by a bacterial infection (endocarditis) or myocardial infarction. In such cases, symptoms include sudden and severe shortness of breath caused by pulmonary congestion and fluid accumulating in the pulmonary alveoli (pulmonary oedema).
 
In addition to traditional chest echocardiography, mitral regurgitation can be assessed by transoesophageal electrocardiography, which is similar to gastroscopy. Severe mitral regurgitation is treated by repair or replacement surgery. If the surgical operation presents a great risk, regurgitation can sometimes be reduced in a catheter-based operation.
 

Mitral valve stenosis

 
In the Finnish population, mitral valve stenosis is very rare. This is because the most common cause of mitral valve stenosis is rheumatic fever, which is nearly extinct in Finland. Rheumatic fever is a sequela of throat infections caused by specific streptococcus bacteria and can damage the heart valves by causing the valves to become inflamed. Over time the leaflets of the inflamed valves become scarred, thickened, and rigid, and stick together causing stenosis. Rheumatic fever is still common in Africa, for example, and the majority of newly diagnosed mitral valve stenoses affect immigrants. Mitral valve stenosis restricts blood flow from the left atrium to the left ventricle, which may cause pulmonary congestion and increase pulmonary blood pressure.
 
The most common symptom is shortness of breath during activity, but atrial arrhythmia (atrial fibrillation) is also common. Mitral valve stenosis and its degree of severity are clearly visible in echocardiography. An experienced cardiologist can detect mitral valve disease and its degree during auscultation. If calcification is not a problem, mitral valve stenosis can be treated with balloon valvuloplasty. However, if balloon valvuloplasty is not possible, mitral valve stenosis must be treated surgically.