Pulmonary hypertension

Pulmonary hypertension: description

Pulmonary hypertension (PH for short) is a disease in which the pulmonary vessels are constricted due to different causes. This increases the blood pressure in the pulmonary circulation – one also speaks of pulmonary hypertension.

In the pulmonary circulation, also known as the small circulation, the following happens: The blood is transported from the heart to the lungs and back again. The oxygen-depleted blood enters the lungs from the right ventricle via the pulmonary trunk, which divides into the right and left pulmonary artery. There it is enriched again with oxygen.

The constricted vessels in pulmonary hypertension increase the resistance in the lungs. This makes it difficult for the right ventricle to pump blood through the lungs. The result: The blood flow through the pulmonary arteries is disturbed and the blood pressure is increased, the right ventricle is increasingly overloaded. Further consequences can be a circulatory disturbance of the lung and a decreased oxygen uptake in the lungs. In the worst case, pulmonary hypertension leads to heart failure.

At an early stage, pulmonary hypertension often causes no symptoms. Only when the disease progresses, complaints occur. Since the body is no longer adequately supplied with oxygen in pulmonary hypertension, those affected are severely limited in their physical performance, quickly exhausted and complain of symptoms such as shortness of breath. Left untreated, pulmonary hypertension can be fatal.

In medicine, a distinction is made between primary and secondary pulmonary hypertension: in very rare cases, pulmonary hypertension occurs as a distinct disease (for example, through heredity), then it is referred to as primary or idiopathic pulmonary hypertension (IPAH for short). As a rule, the causes of pulmonary hypertension are chronic diseases, certain medications or drugs. Then there is talk of secondary pulmonary hypertension.

In the therapy especially the early detection of the underlying disease is important so that the pulmonary hypertension does not progress further. In most cases, pulmonary hypertension is treated by medication to reduce pulmonary hypertension.

Pulmonary hypertension: symptoms

In pulmonary hypertension, symptoms are often absent in the early stages of the disease. Only with the progress of the disease sufferers perceive discomfort. Due to the reduced oxygen supply of the lungs, they are severely limited in their performance. Typical symptoms of pulmonary hypertension are:

• inefficiency
• Rapid fatigue
• shortness of breath
• dizziness
• Possibly. sudden, brief unconsciousness (syncope) with physical exertion
• Bluish discoloration of the skin and lips (cyanosis)
• chest pain
• Swelling due to fluid deposits in the tissue (edema), especially in the legs

On the one hand, the narrowed vessels worsen the oxygen supply to the lungs, on the other hand, the heart requires more and more force to pump the blood through the vessels. The heart has to beat faster and results in an accelerated heart rate, which can also be felt in cardiac arrhythmia. The heart is increasingly burdened, especially the right atrium and the right ventricle are affected. It can develop a right heart weakness (right heart failure).

Pulmonary hypertension: causes and risk factors

Pulmonary hypertension is defined as an increase in the mean blood pressure of the pulmonary artery (pulmonary artery), the so-called pulmonary arterial pressure (PAPm). In a healthy person, the value for the pulmonary mean pressure at rest is less than 20 mmHg. Pulmonary hypertension is present when the level increases to more than 25 mmHg at rest and to over 30 mmHg during exercise.

The cause of pulmonary hypertension is a constriction of the pulmonary vessels, which reduces the volume of the vessels and reduces blood flow. The reason for the vasoconstriction is an imbalance between certain messengers that regulate vasodilatation or vasoconstriction. The cause of this imbalance is unknown. In this case, cells of the inner vessel wall (endothelial cells), the inner layer and the smooth vascular musculature of pulmonary arteries are increasingly exposed to vasoconstrictor messengers (such as endothelin, serotonin, thromboxane). At the same time, vasodilatory messengers (such as prostacyclin or nitric oxide) are present in reduced numbers. As a result, the vessels contract. However, the vasodilating substances also lead to increased cell growth, so that thicken the vessel walls and constrict the vessels more and more. As a result of these processes, the volume of the vessels decreases: less blood can flow through them, and at the same time the lower volume also increases the resistance, which increases the pressure with which the blood flows through the vessels. This also increases the burden on the heart. Due to the higher resistance in the vessels, it must expend more and more force to pump blood into the pulmonary circulation. Over time, the right ventricle enlarges and the muscle of the heart wall thickens until the heart is no longer able to pump enough blood. From this, a so-called right heart insufficiency can develop.

Physicians distinguish a primary from secondary pulmonary hypertension. Primary or idiopathic pulmonary hypertension (IPAH) occurs as a separate disease without known cause, so there is no underlying cause as the cause. The IPAH can be inherited: If two or more family members are affected in a family, the so-called familial pulmonary hypertension (FPAH) is mentioned. However, both forms of pulmonary hypertension are extremely rare: the number of new cases of both forms together is only one to three cases per million inhabitants per year.

In most cases, a certain underlying disease is the cause of pulmonary hypertension. Then there is talk of secondary pulmonary hypertension; pulmonary hypertension is therefore the result of the underlying disease. Especially patients with left heart failure or chronic lung diseases often suffer from pulmonary hypertension. Diseases that can cause pulmonary hypertension include:

• COPD (chronic obstructive pulmonary disease): It is the most common cause of pulmonary hypertension.
• Pulmonary fibrosis: In this disease of the lung tissue, connective tissue is increasingly formed, causing it u.a. reduced oxygen uptake comes.
• Connective tissue diseases such as the so-called CREST syndrome or scleroderma
• Pulmonary embolism (blockage of blood vessels of the lung)
• HIV infection
• Left heart disease
• liver disease
• Schistosomiasis (schistosomiasis): This disease caused by worms is a common cause of pulmonary hypertension, especially in South America.

Certain risk factors that can cause pulmonary hypertension include certain drugs such as appetite suppressants (anorexics) and substance abuse.

Depending on the cause, pulmonary hypertension is divided into five categories:

• Pulmonary Arterial Hypertension (PAH)
• Pulmonary hypertension in left heart disease
• Pulmonary hypertension in lung diseases and / or hypoxemia (low content of oxygen in arterial blood)
• Pulmonary hypertension due to chronic thrombotic and / or embolic diseases
• Pulmonary hypertension due to other unclassified diseases

Pulmonary hypertension: examinations and diagnosis

The pulmonary hypertension is often difficult to diagnose at the beginning, because the complaints are quite unspecific and also occur in other diseases. A detailed conversation on the history of the disease (anamnesis) as well as a physical examination provide important information. If there is a suspicion of pulmonary hypertension, the doctor has various methods available to examine the heart and lungs:

• An ultrasound examination (echocardiography) of the heart is the most important examination method for pulmonary hypertension. This allows the physician to examine the size and function of the heart and to examine the heart wall and movements of the heart valves. In addition, it is possible for him to represent the blood flow in the heart and to record the speed of the blood stream. He can thus estimate an increased blood pressure in the pulmonary arteries (pulmonary-arterial systolic pressure).
• With an X-ray examination of the chest doctor can see extended pulmonary arteries (pulmonary arteries). However, these are only recognizable at an advanced stage of the disease, so that an X-ray examination in the early stages of pulmonary hypertension is not very meaningful.
• Also important is an electrocardiogram (ECG). With this method, the electrical activity of the heart is measured: The doctor receives, for example, information about the heart rhythm and the heart rate. If pulmonary hypertension is present, characteristic changes in the ECG are recognizable.
• Pulmonary function tests are also performed to diagnose pulmonary hypertension. The so-called spirometry measures the lung or respiratory volume: In this examination, the patient breathes into a special device, the spirometer, which measures the amount of air flowing through. This study is designed to assess the severity, prognosis and course of pulmonary hypertension. It can also provide clues to the cause of pulmonary hypertension.
• In order to confirm the diagnosis of pulmonary hypertension and to determine the severity of the disease, a so-called right heart catheter examination is suitable. With it, the pulmonary arterial blood pressure can be measured directly.

The so-called six-minute walking test provides information about the degree of physical resilience in pulmonary hypertension. He measures the distance a patient travels at a comfortable pace in six minutes.

If the diagnosis is pulmonary hypertension, divide its severity into one of four degrees of severity:

• Class 1: No restriction of physical activity. Normal loads do not cause discomfort.
• Class 2: Slight restriction of physical activity, no discomfort at rest. Normal physical activity causes increased breathlessness or fatigue, weakness, or chest pain.
• Class 3: Significant restrictions in physical activity, no discomfort at rest. Light activities cause complaints.
• Class 4: Patients with pulmonary hypertension of this severity can not perform any physical strain without discomfort. In addition, there is a right heart weakness, breathlessness and / or fatigue occur already in peace. Least activity leads to an increase in symptoms.

Pulmonary hypertension: treatment

In pulmonary hypertension, one either treats the underlying disease leading to pulmonary hypertension, or relieves the symptoms it causes through treatment. Because a cure of pulmonary hypertension is not possible. The goal is to extend life expectancy and improve physical fitness and quality of life.

The treatment of pulmonary hypertension usually takes place with medication. Depending on the cause of the disease, blood pressure lowering or vasodilator agents are used. These include, for example:

• High-dose calcium channel blockers: These drugs lower blood pressure in the lungs, but are only used in patients with idiopathic pulmonary hypertension (IPAH). In addition, their efficacy is previously tested with a right heart catheter.
• Prostacyclin derivatives (prostanoids): They are similar to the body’s own messenger prostacyclin and have vasodilator effect. These drugs are given either in the vein or with the help of an inhaler.
• Phosphodiesterase (PDE) 5 inhibitors: drugs in this group lower blood pressure in the pulmonary vessels.
• So-called endothelin receptor antagonists counteract the body’s own messenger endothelin, which has a vasoconstrictor effect.

For example, if chronic obstructive pulmonary disease (COPD) is the cause, then pulmonary hypertension may be treated with long-term oxygen therapy (with home-based mask ventilation) to improve respiratory distress. If the drug therapy of pulmonary hypertension does not succeed, a heart-lung transplantation is often the last treatment option.

In pulmonary hypertension, there is no uniform treatment – it depends on the underlying disease and the severity of pulmonary hypertension. The therapy is therefore individually tailored to the patients.

Pulmonary hypertension: prevention

Since pulmonary hypertension occurs only in very rare cases as a separate disease, but as a result of chronic diseases, it is important to treat them early. This is the only way to prevent a pulmonary hypertension. Regular medical check-ups are therefore essential, especially if there is already a condition that is considered a risk factor for pulmonary hypertension.

People with pulmonary hypertension should avoid heavy physical effort. This is especially true for strenuous athletic activities that are not monitored by a doctor because they can lead to a further increase in pulmonary hypertension. However, a physician-supervised physical training can improve the condition of many patients and be a useful therapy supplement.

In addition, patients suffering from pulmonary hypertension are advised against traveling at heights of more than 2,000 meters. staying in such heights can worsen the condition. Also air travel are therefore by the pulmonary hypertension a potential risk.

Pulmonary hypertension: disease course and prognosis

Pulmonary hypertension is usually due to chronic diseases of the lungs or the heart. A pulmonary hypertension is not curable – in the worst case, it leads to a right heart failure. Treatment can extend life expectancy and increase the overall quality of life.

The prognosis in pulmonary hypertension also depends on how high the blood pressure in the lungs already is – the higher the arterial-pulmonary pressure (PAPm), the worse is the so-called 5-year survival: it decreases, the higher the PAPm Values ​​are greater than 30 mmHg. If no treatment is given, the average life expectancy after diagnosis is no more than three years.