Valvular Heart Disease
Valvular heart disease is a whole group of disorders affecting one or more heart valves. Some minor defects of heart valves are quite common and absolutely asymptomatic. On the other hand, more serious valve disorders may seriously endanger the patient’s life.
There are four heart valves – two of them between atrium and ventricle (mitral valve in the left side of the heart and tricuspid valve in the right) and two semilunar valves between a ventricle and its artery (aortic valve between the left ventricle and the aorta and the pulmonary valve between the right ventricle and the pulmonary artery). The valves work (open and close) in strict coordination with the heart muscle contractions so they allow one-way blood flow from atria to ventricles and further into arteries getting out of heart.
No matter the causative factor, the valvular heart disease has two mechanical forms – valvular stenosis and valvular insufficiency. Stenotic valve is narrowed and creates an excessive resistance to the blood flow. Insufficient valve is unable to close and therefore it allows a backflow of blood.
There are numerous causes of the valve dysfunctions. In addition to congenital disorders there are many factors causing damage of previously healthy valves, for example infective endocarditis, rheumatic fever (valve insufficiency) and gradual age degeneration (valve stenosis). The flaps may be damaged even by a strong heart attack, which injures the tissue controlling the valve movement and causing valve insufficiency.
Impaired valve function disrupts more or less the pumping function of the heart. There are usually present symptoms of heart failure and the most present sign depends on the type of valve and the type of its failure (narrowing or insufficiency). The symptoms may include shortness of breath, weakness, and bouts of unconsciousness. Many heart arrhythmias may occur, typically the atrial fibrillation that threatens the affected person with an ischemic stroke. Patients with valvular disorders have a higher chance of development of infective endocarditis.
Medical history should be focused on present symptoms and physical examination on chest auscultation by a stethoscope. Valvular heart disease usually manifests with a heart murmur. Skilled physician not only hears the murmur but can also estimate, which valve is damaged, and how. A murmur is either caused by blood that flows through a stenotic valve or blood that returns through an insufficient valve. Many murmurs are absolutely innocent (especially in children) and their noise is not always proportional to the severity of valvular disorders. When diagnosing a murmur, it is advisable to perform an echocardiography to precisely visualize the heart, the valves and their function. The echocardiography can not only confirm a valve disorder but also evaluate its severity.
Insignificant valvular disorders are usually only monitored. Major defects are primarily treated by surgery when the damaged valve is removed and replaced by an artificial one (biological or mechanical). Biological artificial valve has usually short lifespan but on the other hand, mechanical valves require anticoagulation therapy.