Valvular heart disease

introduction

Overall there is four heart valveseach of which can be damaged in two directions by different causes. The four heart valves ensure that the heart can fill sufficiently during the relaxation phase and that the blood can be pumped in the right direction during the ejection phase. Ultimately, they're basically there to ensure that blood is only pumped in one direction.

Read more about the topic here: Heart anatomy

With a heart valve disease one differentiates one Stenosis from one insufficiency. With a stenosis, the heart valves do not open completely, so less blood can be expelled. This creates one at the level of the heart valve Bottleneck. As a result, on the one hand, the blood accumulates in front of the narrowed valve and, on the other hand, increased pressure has to be applied to continue pumping the blood. In the case of insufficiency, however, there is practically a leak - the valve does not close tightly, so that blood can seep through the valve, which is actually closed.

Both stenosis and insufficiency put more strain on the heart. The increased exertion results in a thickening of the heart muscles, as well as a compensatory enlargement of the heart chambers. A larger heart needs more oxygen and nutrients than a healthy heart. In the long run, the supply of the heart muscles is insufficient and cardiac insufficiency develops. If the heart is weak, the heart is no longer able to cope with the demands and it can no longer supply the body with sufficient oxygen-rich blood.

A stenosis and insufficiency of a heart valve can be acquired in the course of one's life, for example in the context of inflammation (endocarditis = inflammation of the inner lining of the heart that also covers the heart valves) or calcification of the heart valves, or it is a congenital disorder.

Also read the article: Aortic stenosis.

Function and anatomy of the four heart valves

There are four different heart valves: Aortic valve, Pulmonary valve, Tricuspid valve and Mitral valve. The mitral valve in the left part of the heart and the tricuspid valve in the right part of the heart separate the atria from the ventricles. During the filling phase of the heart, the diastole, both valves are open so that blood can flow from the circulatory system through the atria into the chambers. During the ejection phase, the Systole, both valves are closed so that the blood cannot flow back towards the atria.

The other two valves, aortic and pulmonary valves, are located at the two exits of the heart. The Pulmonary valve is located in the right chamber. It represents the gateway from the right ventricle to the pulmonary circulation. The oxygen-poor blood flows through it, which then flows into the Pulmonary circulation is enriched with oxygen. The Aortic valve is located in the left ventricle. The oxygen-rich blood flows from the left ventricle into the aortic valve Body circulation pumped. The aortic and pulmonary valves are closed during the relaxation phase so that the heart can first fill and build up sufficient pressure. These flaps are then open during the ejection phase.

Read more about the topic here: Heart valve anatomy

Oxygen-poor, venous blood flows from the body's circulation into the right atrium, from there via the tricuspid valve into the right ventricle. The blood then reaches the pulmonary circulation via the pulmonary valve, which ultimately flows into the left atrium. The blood, which is now enriched with oxygen, flows via the mitral valve into the left chamber and from there via the aortic valve into the main artery, i.e. the arterial body circulation. The blood can then supply organs and muscles etc. with oxygen and nutrients.

There are two types of heart valves: the Pocket flaps and the Sail flaps. The aortic valve and the pulmonary valve belong to the pocket valves. The tricuspid valve and the mitral valve, however, belong to the leaflet valves.

The pocket flaps are made up of three crescent-shaped pockets and the material corresponds to the inner lining of the heart. Aortic and pulmonary valves correspond in structure, with the aortic valve being larger and thicker because it is subjected to greater pressure in the left part of the heart than the pulmonary valve. The tricuspid valve consists of three leaflets, while the mitral valve (also called the bicuspid valve) consists of two leaflets. This is where the names of the two flaps are derived. The individual leaflets of the valves are attached to the so-called papillary muscles via fine tendon threads, which in turn protrude into the heart chamber. The way in which the leaflet valves are attached prevents the individual leaflets from penetrating into the atrium as the chamber fills with blood.

The individual heart valve diseases

In the following, the stenosis and insufficiency of the individual heart valves will be discussed in more detail.

Aortic stenosis

Aortic valve stenosis is the most common heart valve disease. Sometimes there is aortic valve stenosis combined with mitral valve regurgitation. In most cases it is a acquired cause, such as inflammation or calcification. Calcification is not uncommon in old age. It is a degenerative process, so that the stenosis continues to increase and the heart is increasingly stressed.

Read more about the topic here: Aortic stenosis

A calcification is the most common cause of acquired aortic stenosis. Around three to five percent of all people over the age of 75 have aortic valve stenosis due to calcification. A high blood pressure, Smoking, increased blood lipid levels and a Sugar disease favor both a calcification of vessels and a corresponding calcification of heart valves. This leads to a reduced mobility of the flap, so that it can no longer open completely. Congenital aortic valve stenosis, on the other hand, can exist, for example, when only two pockets are created instead of the usual three pockets in the valve. If there is also calcification, a stenosis can develop.

If there is a stenosis of the aortic valve, this manifests itself from a certain degree of the disease with various symptoms similar to those of a threatening one Heart attack resemble. For one thing, you may experience chest tightness or chest pain (Angina pectoris), as well as dizziness and fainting. (Caused by a briefly low blood pressure, so that the brain cannot be supplied with sufficient blood temporarily.) Shortness of breath or lightness is also typical Shortness of breath. All of these symptoms usually occur with increased stress.

If the degree of stenosis increases, the symptoms appear even with milder ones physical exertion on. However, these symptoms are not specific to aortic valve stenosis, but can also occur with other valve diseases. Aortic valve stenosis or valve disease in general often goes undetected because it occurs silent, i.e. without symptoms. But how do you explain these symptoms?

Due to the stenosis, the oxygen-rich blood has to leave the blood at increased pressure left ventricle be pumped into the main artery. From a certain degree of damage, blood remains in the left ventricle. As a result, more blood collects in the left ventricle in the next phase and there is a higher level of stress. The heart musculature thickens in a compensatory manner and the heart chamber ultimately becomes larger in the long run. At some point the heart can no longer be supplied with enough oxygen, causing it to develop a Heart failure comes.

If the aortic stenosis is severe and has symptoms, the valve must be replaced. Instead of a valve replacement, the aortic valve can also be "blown up" using a small balloon that is pushed towards the heart via an inguinal vessel and then inflated at the position of the heart valve so that it can be fully opened again.

Read more about the topic here: Artificial heart valves

Aortic regurgitation

In the case of aortic valve insufficiency, the valve does not close properly during the relaxation phase, so that blood that was previously pumped into the body's circulation can flow back into the left ventricle. If the heart has to pump the blood back into the body's circulation in the next cycle, a higher volume has built up. This must be the heart more power and pressure spend. As with an aortic stenosis, the increased pressure leads to an enlargement of the chambers and a thickened muscle layer.

Read more about the topic here: Aortic regurgitation

Aortic valve insufficiency is usually due to a Inflammation (endocarditis) conditionally. The inflammation can be caused by a bacterial infection, calcifications, rheumatic fever (which is rarely seen today) or the autoimmune disease Lupus erythematosus arise. The risk of bacterial infection is increased if the valves are already damaged. Congenital aortic regurgitation is very rare.

In most cases, patients experience aortic regurgitation no symptomsbecause it is usually a creeping process to which the heart can adapt. Sometimes the patients noticed an increased heartbeat (palpitation). However, if it is an acute aortic valve insufficiency, for example due to the rupture of a pocket as part of an inflammatory process, severe symptoms can result. The heart has not grown in an acute event of the insufficiency and there is a backlog of blood in the lungs and body circulation. This can lead to a Pulmonary edema, as well as edema on the lower legs (fluid retention in the tissue). Symptomatically, this manifests itself primarily as a shortage of breath.

In contrast to a stenosis, there are other therapeutic methods in addition to valve replacement for insufficiency. Before replacing the valve, an attempt can be made to reconstruct the valve to a certain extent so that it closes again sufficiently.

Mitral valve stenosis

If there is a mitral valve stenosis, the blood cannot drain sufficiently left atrium flow into the left ventricle because the valve does not open fully. In the left atrium, therefore, increased pressure and accordingly increased muscle work must be exerted in order to pump the entire blood volume into the left ventricle as much as possible.

Read more about the topic here: Mitral valve stenosis

Acquired causes of mitral valve stenosis can also Inflammation or degenerative processes - the typical cause with 99%, however, in contrast to the other valve diseases rheumatic fever But also congenital causes can trigger a stenosis of the mitral valve. The stenosis causes blood to accumulate in front of the left ventricle in the left atrium. If the heart fails to master its position, blood can build up in the lungs. The patient perceives this as being short of breath.

Over time, the pressure in the pulmonary circulation increases, which is usually very low, making it difficult for the right heart to keep pumping blood. It comes to one Right heart failure. The chronic pressure increase in the left atrium can also lead to atrial fibrillation, which increases the risk of Blood clot formation with a stroke or one Pulmonary embolism increased as a result. If the stenosis is so advanced that heart failure occurs, the main symptoms are shortness of breath and fatigue.

The backflow of blood into the body causes fluid to accumulate in the lower legs, the veins in the neck are congested and the liver can congest. Furthermore, there may be night-time and sometimes bloody coughs. If the valve becomes symptomatic, the heart failure can be treated with medication. But also a surgical valve replacement it is an option. Here, too, as with aortic stenosis, an expansion using a balloon is possible.

It used to be quite common as part of a rheumatic fever, which can result from a scarlet fever or streptococcal infection, to mitral valve stenosis. Since medicine is now more advanced and infections can usually be treated with an early dose of antibiotics, mitral valve stenosis has become very rare.

Mitral valve regurgitation

Mitral valve regurgitation is the second most common valve disease after aortic valve stenosis. It comes to one decreased ability to close the mitral valve between the left ventricle and the left atrium. Through the leak, blood can flow back into the left atrium during the ejection phase. This leads to volume loading of the left atrium.

Read more about the topic here: Mitral valve regurgitation

At the same time, however, more blood is pumped into the left ventricle during the next filling phase, so that the volume of the left ventricle is also stressed. Ultimately, the blood can get back into the Pulmonary circulation back up and one forms Heart failure out. The symptoms are similar to those of the other valve diseases: decreased performance, fatigue, difficulty breathing and heart palpitations. Atrial fibrillation can sometimes also occur.

A distinction is made between one in mitral valve regurgitation acute and chronic illness. The chronic disease remains clinically silent for a long time and the symptoms appear only insidiously. In acute illness, the symptoms appear quickly. Reasons for acute mitral valve insufficiency are, for example, bacterial infection of the valves (endocarditis) with destruction of the pocket valves and / or the tendon threads. As part of a Heart attack the papillary muscles, which are also essential for the function of the leaflet valves, may tear.

The number one cause of chronic insufficiency is one Bulging of the mitral valve in the left atrium (mitral valve prolapse), which should normally be prevented by hanging it on the tendon threads and papillary muscles. The bulge prevents the flap from closing properly. Endocarditis, coronary heart disease, autoimmune diseases or the use of appetite suppressants can also provoke a chronic disease. Before replacing the valve in symptomatic mitral regurgitation, one first tries to surgically reconstruct the valve.

Pulmonary valve stenosis

While other valve disorders are commonly acquired, pulmonary valve stenosis is one mostly innate. In the case of pulmonary valve stenosis, the pulmonary valve does not open completely, so that the blood accumulates in front of the valve in the right ventricle. So there is a pressure load on the right ventricle.

The valve disorder is usually symptom-free over a long period of time and only manifests itself in the form of a higher-grade damage Chest pain (Angina pectoris), Shortness of breath and occasional Fainting spells (Syncope). The symptoms come in the wake of a Right heart failure conditions. In most cases, an attempt is made to expand the heart valve by inserting a small balloon so that it can open completely again. Glued flaps can be blown open.

This operation is already carried out in children, as pulmonary valve stenosis often occurs in childhood. An operation is necessary if the Opening area the flap is severely restricted. If the damage is only slight, those affected usually remain symptom-free into adulthood. If the valve is already too damaged, an artificial valve must be used instead of a balloon expansion. In childhood, one tries to avoid a valve replacement, because the new valve does not grow like the body's own valve and so over time is no longer able to cope with the demands of the body.

Pulmonary valve regurgitation

If the pulmonary valve is not completely closed during the filling phase, blood from the pulmonary circulation can return to the right chamber flow. This means that the patient has to use increased force during the next ejection phase in order to pump more volume into the pulmonary circulation. In the long run there is an enlargement of the right half of the heart and the formation of a Right heart failure.

In most cases, pulmonary valve regurgitation is permanent symptomless Illness. For example, it can be caused by endocarditis, rheumatic fever, trauma during heart surgery, or it can be congenital. In most cases, however, it is caused by increased pressure in the pulmonary circulation.

With pulmonary valve insufficiency, the body has practically found a way to reduce the pressure in the pulmonary circulation because the leakage means that there is less blood in the pulmonary circulation. The pulmonary valve insufficiency will only secondary therapy. One tries primarily to treat the cause of the increased pressure in the pulmonary circulation. If the lung pressure normalizes, the pulmonary valve insufficiency usually also regresses. The pulmonary valve is rarely replaced. This is considered when symptoms of heart failure are already emerging.

Tricuspid valve stenosis

Tricuspid valve stenosis is one of the now rare valve diseases. It is usually triggered by rheumatic endocarditis, which is now easily treatable. When the stenosis occurs, it usually occurs in combination with another valve defect - this also applies to tricuspid valve regurgitation. A stenosis of the tricuspid valve often occurs together with a mitral or aortic valve stenosis.

Tricuspid valve stenosis can also be congenital or occur in the context of various diseases, such as Fabry's disease, Whipple's disease or a carcinoid (hormone-producing tumor). Due to the stenosis of the tricuspid valve, the blood cannot flow completely from the right atrium into the right ventricle during the filling phase. There is a volume load on the right atrium. As a result, blood backs up in the venous systemic circulation and ultimately right heart failure.

If tricuspid valve stenosis occurs with mitral valve stenosis, there is usually no increase in lung pressure. This is because tricuspid valve stenosis prevents too much blood from flowing into the pulmonary circulation, so that the pressure does not increase significantly despite mitral valve stenosis. The tricuspid valve stenosis thus has a favorable prognostic effect on an existing mitral valve stenosis. As a rule, the tricuspid valve can be reconstructed when it becomes symptomatic and a valve replacement can be dispensed with.

Tricuspid regurgitation

As already mentioned, diseases of the tricuspid valve rarely occur in isolation. Tricuspid regurgitation is usually the trigger not innate, but secondary to a valve defect in the left heart. If there is damage to the aortic or mitral valve, the blood backs up into the right heart, so that the right heart wall, including the valve, is exposed to increased pressure.

The heart valve ring to which the individual leaflets attach is pushed apart. As a result, the sails are further apart and can no longer close completely. A pulmonary embolism has a similar effect, which also increases the pressure in the right heart. As with the other valve defects, endocarditis or the tearing of a tendon thread or papillary muscle can also be responsible. An infection of the tricuspid valve usually only occurs in people with one weakened immune system occurs.

Symptomatic tricuspid valve regurgitation can lead to congestion in the body's circulation. Depending on how much the valve is damaged, there is both the possibility of reconstructing the valve and replacing it.