Heart valve disease: onset, manifestation and classification

Heart valve diseases have different origins. They can be congenital or acquired during one's lifetime.

Initially, the manifestation of a valve defect may be in form of less severe health problems. Later on, more severe symptoms may be associated. Ultimately, this disease can lead to heart failure.

The heart is...

The heart is a muscular organ whose main task is to pump blood throughout the body.

This pump pumps approximately 5 litres of blood in one minute. It is about the size of a clenched fist and weighs about 250-350 grams.

Heart weight in women = 250 - 300 grams, over 350 grams hypertrophy.
In men, the heart weighs 300-350 grams, if it weighs over 400 grams, the condition is called hypertrophy. 
An enlarged heart may be physiological or pathological.

You will find more information in the article on cardiomyopathy.

The heart consists of heart muscle, or the myocardium.
On the outside, the muscle is surrounded by a membrane called the epicardium.
The outer sac in which the heart is stored is the pericardium.

The inner side of the heart muscle is covered by the endocardium.
This membrane is in contact with the blood.
It also forms the heart valves.
It passes smoothly to the inner layer of blood vessels.

The heart is divided into 4 chambers or cavities: right atrium, right ventricle, left atrium and left ventricle.

Deoxygenated blood, or blood without oxygen, is carried by the veins to the right heart.
From there, it goes through the pulmonary artery to the lungs.
In the lungs, the blood is reoxygenated.

Oxygen-rich blood is routed from the lungs through the pulmonary veins to the left heart.
It then goes from the left ventricle through the aorta to the whole organism.

Blood vessels that carry blood TOWARDS the heart = veins.
Blood vessels that take blood AWAY FROM the heart = arteries.

The aorta, the largest artery in the body, protrudes from the left ventricle. The heart expels oxygenated blood into it from where the blood is transported further into the whole organism.

This blood cycle is also referred to as the circulatory system or the cardiovascular system.

Circulation between heart and lungs = minor blood circulation or pulmonary circulation.
And... 
Circulation between the heart and the rest of the body = large blood circulation or systemic circulation.

The two cardiac cycles alternate during the pumping activity of the heart. They are called systole and diastole.

1. Systole is a state of contraction of the heart muscle. The blood is then pushed out of the heart cavity. 
2. Diastole, on the other hand, is a condition of a relaxed heart muscle. During this phase, the heart cavities are filled with blood.

The pumping of blood and blood flow are constant thanks to the continuous activity of the heart.

There are heart valves between the cavities of the heart as well as between the cavities and the vessels. Their function is to ensure that the blood flows in one direction into and away from the heart.

Imagine a one-way valve.
The valves open and close based on a pressure gradient.

When the blood is ejected, i.e. during systole, the valves open and allow the blood to flow smoothly. During diastole, i.e. when the heart muscle relaxes, the valves close, which prevents backflow.

We recognize several types of valves:

• tricuspid valve - valva atrioventricularis dextra - tricuspidalis
  • placed between the right atrium and the right ventricle
  • prevents blood from flowing back from the right ventricle to the right atrium
• pulmonary valve - valva trunci pulmonalis
  • located between the right cardiac ventricle and the pulmonary artery
  • prevents blood from flowing back into the right ventricle
• mitral valve - valva atrioventricularis sinistra - bicuspidalis, mitralis
  • located between the left atrium and the left ventricle
  • prevents blood from flowing back from the left ventricle to the left atrium
• aortic valve - valva aortae
  • is between the left ventricle and the aorta
  • prevents backflow from the aorta to the left ventricle

Healthy valves help ensure smooth blood flow. They open about 40 million times a year and, in a lifetime, these valves will open and close roughly 2.5 billion times.

Read on to find out the answers to the following questions: 
What are valve diseases?
What are their causes?
How do they manifest?
What is the treatment?

Heart valve diseases

Heart valves can be affected by various diseases. These will cause them to malfunction, which results in health risks.

Heart valve diseases are either congenital, i.e. inborn, or acquired during our lifetime.

In essence, these diseases damage the valve structure, which results in impaired activity. Valve diseases are categorised by type of abnormality.

Heart valve disorders are divided into two main groups, namely:

1. stenotic disease - narrowing of the blood flow area
2. insufficiency/regurgitation disease - insufficient valve closure with backflow of blood

Table: classification of valve diseases

Depending on the form of damage and disability of a particular valve, valve defects are also indicated individually.

Table: individual valve diseases

Summary:

As the valve narrows, the heart must withstand higher pressure to expel blood from the heart compartments. The heart muscle is overworked. With increased exertion, the heart muscle thickens - hypertrophies.

Incomplete closure of the valve causes partial backflow. Regurgitation increases the amount of blood in the heart or the lungs. The blood accumulates, i.e. stagnates.

The heart must pump the blood flowing from the body, as well as the blood that accumulates in the heart. This situation increases the demands on the heart muscle, as a result of which it dilates, i.e. expands.

The blood circulation receives a reduced amount of blood.

Long-term increased load exhausts the compensatory abilities of the heart. Furthermore, it can no longer adapt to high demands, which initially makes it a problem during physical exertion, and at a later stage also at rest.

Heart weakens = functionally fails.

In most cases, both types of valve dysfunction occur simultaneously as a combination. One or more valves may be damaged.

Atresia is a special type of valve defect.
Atresia = abnormal development or complete absence of a valve.

The causes of heart valve disease are diverse.

Children are reported to have valve congenital defects and conditions. For example, a cause may be congenital and genetically determined abnormalities of connective tissue.

The second group comprises acquired causes, which arise during one's lifetime.

They are age-related degenerative changes that result from wear and tear, ischemia, or bloodlessness.

Contributing risk factors also include coronary heart disease, heart attack, and high blood pressure.

Another problem is a change in the size of the heart cavity, when geometric disparities have a negative effect on the functionality of the valves. Such as in cardiomyopathy.

Today, the degenerative process is more prevalent: calcium deposition and fibrotization impair the functional properties of the valves.

However, valve disease can also have other causes.

The causes of valve errors can be summarised as follows:

• birth defects and abnormalities
• degenerative changes and calcium deposition and valve fibrotization
• inflammatory diseases
  • rheumatic fever
  • endocarditis - inflammation of the inner lining of the heart and therefore also the valves
    • bacterial endocarditis
• rheumatoid arthritis
• systemic, autoimmune and rheumatic diseases
  • inflammation of the joints or the spine
    • ankylosing spondylitis - Bechterev's disease, axial spondylarthritis
  • intestinal inflammation, such as ulcerative colitis
  • systemic lupus
• Marfan syndrome
• chest injuries
• aortic dissection
• myxoma and heart tumours

Risk factors that can lead to the problem:

• advanced age
• past and untreated infections, especially of the respiratory tract and tonsils
• heart disease such as ischemic disease

• heart failure
• myocardial infarction
• heart enlargement and cardiomyopathy

• high blood pressure
• elevated cholesterol
• diabetes
• other metabolic diseases
• chest radiotherapy
• smoking
• obesity
• lack of physical activity
• familial history
• congenital heart defects
• sexually transmitted diseases

Heart valve disease presents with primary symptoms, including fatigue, difficulty breathing and chest pain. These three symptoms may accompany others.

Symptoms of valve errors include:

1. fatigue
2. difficulty breathing - dyspnoea, especially during an activity
3. chest pain
4. heart murmurs, evaluated by a doctor during auscultation of the heart with a stethoscope
5. pounding, flattering heart, rapid pulsation - palpitations
6. arrhythmia - heart rhythm disorders
7. dizziness
8. fainting, syncope, collapse, temporary loss of consciousness
9. frequent headache
10. swelling of the limbs

A heart murmur can be a symptom of valve disease.
But...

Murmurs also occur in children, young people, athletes or pregnant women:
It is considered insignificant if it is not a symptom of the disease.

Table: typical symptoms according to the form of the disease

In valve diseases, there is a risk of blood clots forming in the heart. There is a risk of blood clots that can travel in the blood vessels like an embolus.

A serious complication is a stroke.

High risk at a later stage is also due to arrhythmias or cardiac arrest and death.

In diagnosis, auscultation is used as the main method of determining valve dysfunctions.

The doctor can use a stethoscope to determine a possible problem according to the location and nature of the heart murmur.

Heart murmurs are the most frequent cause heart valve failure.

Myocardial contraction and valve closure have a typical sound. A narrowing of a valve or overpressure cause a change in blood flow which is audible as a murmur.

Subsequently, the systolic or diastolic murmur is evaluated. It is determined by the intensity, ranging from the weakest (1) to the strongest (6). At 1, it is difficult to hear, but at 6, the sound is heard even with the stethoscope at a distance.

Other properties of the murmur are also evaluated.

Benign murmur

It often occurs in children and disappears in adulthood.

It is a sound that is created by blood flow as it touches the walls of the heart and blood vessels. It is a systolic murmur - during contraction of the heart muscle and has a low intensity.

A pediatrician can distinguish innocent and pathological murmurs.

It occurs in approximately 80% of children.

There are several types of innocent murmurs thar are described in an article here. 

Of course, in case of doubt, there are certain examinations to rule out the disease.

Other diagnostic methods

Subsequently, the medical history is checked and a physical examination is performed. The patient may also undergo an X-ray, ECG, ultrasound, or catheterization, MRI or stress test.

The course of the disease depends on the extent of valve damage. The greater the extent, the more severe the manifestations.

In some cases, there may be no difficulties at the onset. The disease is reported to be asymptomatic, i.e. without symptoms.

Consequently, over time, the condition is accompanied by fatigue and increased exhaustibility. Headaches, dizziness or fainting are symptoms of insufficient blood supply to the brain.

Physical activity causes severe weakness, dizziness, recurrent fainting, difficulty breathing or chest pain.

The heart can only compensate for these mistakes for a while. Adaptation has its limits, it is influenced by the type of disease and the rate of onset.

The right side of the heart is weaker compared to the left. It fails before the other half does. Also, left ventricular failure may soon be accompanied by right heart failure.

The dysfunction is subsequently manifested by swelling of the lungs or swelling of the limbs. Exercise intolerance, difficulty breathing and other symptoms.

Read also: Heart failure.