Pulmonary heart disease: What is Cor pulmonale, why does it arise and how does it manifest itself?

Pulmonary heart disease, also known as cor pulmonale, is the enlargement of the heart as a result of a lung disease. It arises as a response to increased vascular resistance of the right heart.

There can be several causes.

This enlargement is a response to acute increased pressure. This happens in two forms and two ways.

The heart and pulmonary circulation - the basics

The heart is basically a pump. The heart s constantly pumping blood into the pulmonary circulation system.

The Latin name for the heart: cor.
It weighs roughly 300 - 400 grams. 

The heart is divided into 4 chambers:

1. right atrium
2. right ventricle
3. left atrium
4. left ventricle

The wall of the heart is made up of three layers:

• the heart is placed inside a sac - the pericardium
• the outer layer is the epicardium
• the middle layer is the heart muscle - the myocardium
• the inner layer is the endocardium
  •  acts as a kind of blood–heart barrier
  • lines the heart wall
  • forms and lines the valves

The main executive unit is the cardiac (heart) muscle, havin the biggest size in the left ventricle, since the left ventricle keeps resisting the highest pressure.

Blood circulation consists of: 
lesser circulation = pulmonary circulation 
and
greater circulation = systemic circulation. 

What does this mean?

Deoxygenated blood returns from the body to the right atrium through two large veins. Oxygen is consumed in the body's cells and must be replenished in the lungs.

It reaches the lungs as follows:

Deoxygenated blood moves from the right atrium to the right ventricle.
From the right ventricle through the pulmonary artery to the lungs.
In the lungs, the blood is oxygenated, and bound to haemoglobin.
Haemoglobin has a reddish blood hue and contains red blood cells.

1.34 millilitres of oxygen are bound per gram of haemoglobin.

After the blood is enriched with oxygen, it travels further into the heart, through 4 pulmonary veins and into the left atrium.

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

What about the greater circulation?

The oxygen-carrying blood is back in the heart.

It moves from the left atrium to the left ventricle.
From the left ventricle to the aorta.
And so from the aorta and throughout the entire human body.

During the activity of the heart, there are two phases which alternate around the clock.

That keeps us alive. After all, the brain dies without the supply of oxygen after only a few minutes. The rest of the body cells die off after a short time.

The 2 cardiac cycles are:

1. systole = heart muscle contraction = blood ejection from the chambers
2. diastole = heart chamber relaxation = chambers are refilled with blood

This is how the heart beats, pumps, expels and sucks blood in a cycle.

However, the heart valves play an important role in this blood cycle, too. The valves (flaps) act as one-way inlets. They allow blood to flow forwards and prevent backflow or regurgitation.

When the blood is ejected, the pressure pushes it through the valve. The heart muscle then relaxes, which changes the pressure gradient. The flap closes and prevents the blood from flowing back.

But if the flap is damaged, a problem occurs = a heart valve disorder. To learn more about this topic, read the article on Heart valve disease.

The lesser circulation

The pressure in the pulmonary circulation is low. 

This means that under normal and normal conditions, pulmonary artery pressure is around 20 mm Hg (millimetres of mercury).

At such a low pressure, several times higher blood flow through the lungs is possible. An example is the increase in physical activity and the increased demand for blood and oxygen to the muscle cells.

Compare:

The pressure in the left ventricle during systole exceeds the pressure in the aorta, which is above 80 mm Hg.
Maximum pressure is 120 - 140 mm Hg = systolic pressure. 
The pressure in the right ventricle is 20 = 30 mm Hg. 

When the pressure in the pulmonary artery increases, it is called arterial pulmonary hypertension.

It can have the following values:

• systolic pressure above 35 mm Hg
• mean diastolic pressure above 25 mm Hg
• diastolic pressure above 12 mm Hg

The reasons for this increase in pressure are diverse.

Read on to find out more about:
cor pulmonale, 
its causes, 
its symptoms, 
and treatment. 

What is Cor pulmonale?

Cor pulmonale, or pulmonary heart disease, is a condition where the heart enlarges as a result of a specific pulmonary issue.

It is defined as follows:

It is a condition due to a structural failure of the right heart, i.e. hypertrophy or dilatation. It is caused by an increase in pressure, i.e. pulmonary hypertension.

For more information on hypertrophy and dilatation of the heart, see the article on cardiomyopathy.

It can run its course as an acute, i.e. with a sudden onset, or a chronic form.

Acute cor pulmonale

In the case of an acute form, there is a dilatation of the right ventricle = pathological dilation of the heart muscle of the right ventricle.

Cor pulmonale acutum.

The cause is acute pulmonary hypertension. It most often develops as a result of massive pulmonary embolism.

In case of a large-scale pulmonary embolism, a pulmonary obstruction occurs, which increases the resistance of the right heart. In addition to an increasing resistance, there is blood accumulation in the right ventricle. This enlarges the heart and impairs its function.

Chronic cor pulmonale

As the pressure in the pulmonary circulation gradually increases, the heart muscle of the right ventricle adapts and thickens.

Cor pulmonale chronicum.

It hypertrophies.

The World Health Organization defines chronic cor pulmonale as follows:

Right ventricular hypertrophy due to impairment of lung function and/or structure. It is based on pulmonary disease and arterial pulmonary hypertension.

However, exceptions are conditions that are a direct result of left heart disease and heart failure. These can be caused by a valve disease or a congenital heart defect.

The cause of cor pulmonale is an increase in resistance and pressure in pulmonary arteries.

This increase in pressure can be acute or chronic.

The acute form is dangerous because the heart muscle does not have time to adapt and can fail more quickly. It needs immediate help.

Chronic changes lead to a gradual increase in pressure and muscle adaptation. However, this adaptation will not go on indefinitely, but only until the compensation mechanism is exhausted and the right ventricle begins to fail.

This is referred to as decompensation of chronic cor pulmonale.

Question: But what is the cause of pulmonary heart disease?

We have already mentioned that this is an increase in resistance and pressure in the lungs above 25 mm Hg.

Table: some causes divided into three groups

In case of pulmonary embolism... 

Pulmonary embolism is the entrapment of an embolus, or blood clot, in the pulmonary vessels. 

It is most often caused by a blood clot that forms during deep vein thrombosis in the lower limbs and is then released.

Symptoms, consequences and prognosis depend on the extent of the blockage.

Forms of pulmonary artery embolization:

• Massive form and obstruction of the pulmonary trunk or both of its main branches = sudden death
• Submassive form of clogging of several larger branches = cardiogenic shock
• Minor form - clogging of smaller peripheral branches - easy course, sometimes without symptoms
• Repeated minor embolisations - lead to pulmonary hypertension and COR PULMONALE

Symptoms of cor pulmonale also occur along with manifestations of the underlying disease: chronic obstructive pulmonary disease or pulmonary embolism.

Pulmonary hypertension is the main cause of the problem. As a result, the heart is not able to supply enough oxygenated blood to the body.

Especially during physical exertion.

The main symptoms of cor pulmonale include:

• difficulty breathing
  • shortness of breath, exacerbation of breathing during exertion
• tiredness
• inactivity and increased fatigue
• dry cough
• chest pain
  • without damage to the coronary arteries
    • as is the case with coronary heart disease or heart attack
• a racing heartbeat - palpitations
• collapse, fainting, syncope - recurrent conditions, especially during exertion
• loss of appetite
• weight loss
• upset stomach and dyspeptic problems
• ascites - swelling in the abdomen
• swelling of the lower limbs - equally on both sides as a sign of right heart failure
• coughing up blood

Decompensated chronic pulmonary heart disease has the following symptoms:

• as a symptom of right heart failure
• swelling
  • lower limbs - both
  • progresses from the foot and ankles - higher up
  • up to thighs, abdomen (ascites) to the entire body (anasarca)
• increasing the filling of the jugular veins
• enlarged liver - hepatomegaly
• metabolic disorder
• abnormally lowe level of oxygen in the blood - hypoxemia
• abnormally elevated carbon dioxide levels - hypercapnia

Significant pallour, cold sweat, bluish skin hue - cyanosis, progressive swelling, collapse, impaired consciousness; the presence of convulsions means decompensation of the disease and shock. Immediate treatment is required.

Otherwise there is a risk of death.

In some cases, the symptoms are covered by the primary disease. They are not recognized.

Another example is left-sided heart failure with right-sided failure. There is an accumulation of blood in the greater circulation and in the lungs. 

This could manifest as pulmonary edema. 

Medical history and clinical manifestations of the disease help with the diagnosis. Blood pressure, pulse rate or blood oxygen saturation are measured. Respiration is monitored and examined.

This is where both the symptoms of the primary disease and the lung heart are discovered. However, in some cases, cor pulmonale may not be recognized and is hidden by the underlying disease.

For this reason, other methods are important in diagnosis.

An example is an echo. 

Echo = echocardiography - ultrasound of the heart. This examination evaluates the heart, size, chamber size, wall thickness, and the myocardium. The same goes for the flap structure.

This is one of the most important examinations.

ECK - The record evaluates the presence of a change in the ECG curve with the typical P Pulmonale wave. It is steep and more than 3 mm high.

Next, RTG, CT, MRI are carried out which are also used to assess the size of the heart and its compartments.

Laboratory blood tests may be added to the repertoir of exams.

The course of the disease can be acute, i.e.sudden, or chronic.

Acute = the heart does not have time to adjust to the disease. There is acute failure.

Excessive pressure in the lungs increases the strain on the heart.
This is accompanied by an accumulation of blood in the right heart.
The right ventricle expands - dilatation of the right ventricle.

The duration and progression of the disease takes minutes, hours or days.
An example is massive pulmonary embolism.

Chronic = long-lasting, persistent. Problems (issues, difficulties) are progressing for a long time.

The condition lasts form several months to years. 
For example, the development of chronic obstructive pulmonary disease.

The right heart, i.e. the muscle of the right ventricle, gradually adapts.
The heart muscle is thickening - right ventricular hypertrophy.

However, even this process of adaptation cannot last forever. Once the compensatory mechanisms are depleted, decompensation and heart failure occur. This type of procedure is also referred to as chronic heart failure.

Also: Heart failure can be acute or chronic

The course is complicated by the occurrence of the underlying disease. Therefore, the pulmonary heart may be unrecognized.

The main manifestation of cor pulmonale ...

Dyspnoea is one of the basic symptoms. Breathing can be easy at the onset, so the deterioration comes with increasing effort.

In later stages, however, shortness of breath at rest may also appear.

Dyspnea = sensation of shortness of breath.

Decreased blood supply with oxygen to the body is typically demonstrated as fatigue, exhaustion or reduced exercise tolerance, and shorter time to fatigue.

Heart palpitations occur as a symptom of increased heart rate as a result of the heart's effort to supply the necessary blood. Chest pain is also associated.

However, these chest pains are not accompanied by damage to the coronary arteries. They are caused by insufficient blood supply to the heart muscle due to insufficient blood flow, especially during exertion and accelerated heart activity.

The associated symptom is:

Characteristic of right heart failure = swelling.

This is the result of the accumulation of blood in front of the right heart, i.e. in the greater circulation. The swelling progresses from the feet, the ankles. In later stages, it occurs higher up - the crus (lower leg), thighs, abdomen, the rest of body.

The swelling in this case is bilateral = on both lower limbs.

If only one lower limb is swollen, we have to assume, for example, a vascular disease of the lower limbs.

Increasing pressure in front of the right heart also causes liver enlargement - hepatomegaly.