Pulmonary hypertension

The main symptom is exertion-induced breathlessness. However, fatigue, shortness of breath when bending down and generally reduced physical performance are also cited as indicators. Making the diagnosis of “pulmonary hypertension” and correctly classifying the cause is difficult and requires a lot of experience. Pulmonary hypertension should therefore be urgently clarified by us. Some forms of PH can be treated with medication, others require interventions or even surgery, or the underlying disease needs to be treated. The earlier the appropriate therapy begins, the more favorable the prognosis.

What is pulmonary hypertension?

High blood pressure in the pulmonary circulation is defined as above mean pulmonary arterial pressure > 20 mmHg (millimeters of mercury, normal 14 mmHg). Depending on the pulmonary arterial occlusion pressure or left atrial pressure, pulmonary hypertension is classified as precapillary or postcapillary. This is very important for later treatment.

A right heart catheterization is required for the diagnosis. This should always be done in a center with the possibility of vasoreactivity testing. In this test, patients are given an inhaled agent (usually nitric oxide) during the cardiac catheterization, which greatly dilates the pulmonary vessels in certain patients and thus significantly improves pulmonary artery pressure. Anyone showing such a vasoreactive reaction can be treated with specific agents. Furthermore, at the PH Center of the University Hospital Zurich, the right heart catheter examination is always performed under stress, as the behavior of the pulmonary artery pressure under stress provides further diagnostic and prognostic information. Right heart catheterization in PH therefore requires a lot of experience and should be performed at our center.

How the pulmonary and systemic circulation works

The deoxygenated blood is pumped from the right side of the heart through the pulmonary artery into the lungs, where it is enriched with oxygen. It then returns to the left side of the heart via the pulmonary vein and from there into the systemic circulation to all organs and tissues. The deoxygenated blood from the body is in turn transported back to the right heart via the veins. Then the cycle starts all over again.

The pressure in both circuits is different. It is higher in the large systemic circulation because the blood has to overcome greater resistance than in the small pulmonary circulation. The average pressure in the systemic circulation is 100 mmHg and in the pulmonary circulation an average of 15 mmHg.

Pulmonary hypertension – multiple causes

Pulmonary hypertension manifests itself through various symptoms. The main symptom is shortness of breath during physical exertion, rapid fatigue and reduced performance. The causes can be extremely varied. Experts have therefore categorized pulmonary hypertension into different forms. Pulmonary hypertension is often associated with other diseases, for example diseases of the connective tissue, liver diseases, a congenital heart defect, or it is caused by scarring changes following pulmonary embolisms. These lung diseases are therefore pulmonary vascular diseases, the problem lies in the pulmonary vessels. A distinction is made between PH due to passive congestion in heart failure or due to hypoxic pulmonary vasoconstriction in lung disease; for the latter two forms, the respective underlying diseases must be treated.

Pulmonary hypertension can vary in severity and can severely limit physical performance if doctors do not treat it adequately. Life expectancy also decreases without therapy. Important treatment options for pulmonary vascular disease are drugs that dilate the blood vessels, alleviate symptoms and improve quality of life.

Pulmonary hypertension – frequency and age

Pulmonary hypertension without concomitant diseases is very rare. It hardly ever occurs in everyday medical practice. Experts estimate that around 15 people per million inhabitants suffer from the disease. Every year, there are around one to three new cases per million inhabitants. This means that idiopathic pulmonary arterial hypertension (without other diseases) is one of the rare diseases (“orphan diseases”). In addition, there are forms of pulmonary arterial hypertension that respond similarly to therapy in association with concomitant diseases. It therefore usually takes some time for doctors to diagnose pulmonary hypertension. Pulmonary hypertension can affect people of any age. Women contract the disease more frequently than men.

Pulmonary hypertension: classification

As mentioned above, pulmonary hypertension can have countless causes. Experts divide pulmonary hypertension into five groups – depending on the cause.

Pulmonary arterial hypertension (PAH)

Pulmonary arterial hypertension can be idiopathic, i.e. without an identifiable cause, hereditary (due to a hereditary predisposition), drug-induced or associated with other underlying diseases:

• Idiopathic
• Hereditary
• Connective tissue diseases, e.g. scleroderma, lupus erythematosus or rheumatoid arthritis
• Heart diseases, e.g. congenital heart defects
• Liver diseases, e.g. portal vein hypertension (portal hypertension)
• HIV infection
• Schistosomiasis – a tropical disease caused by the couple fluke.
• Medication: e.g. appetite suppressants or psychogenic stimulants such as amphetamines
• toxins

Although the causes of PAH are very different, they have one thing in common: the walls of the pulmonary arteries change. The following reasons are postulated:

• The balance between vasoconstrictor and vasodilator substances is out of kilter.
• Inflammation contributes to the remodeling of the vascular walls – the vessels constrict, lose their elasticity and can no longer expand properly. This is particularly noticeable when you exert yourself physically.

Pulmonary hypertension due to left heart disease

Pulmonary hypertension is caused by damage to the left side of the heart or the heart valves there. The blood backs up in the pulmonary circulation because the pumping function of the heart is reduced. Heart failure or cardiac insufficiency is the name of the condition in which the heart has lost some of its beating power. In terms of numbers, left heart disease is probably responsible for most cases of pulmonary hypertension.

Pulmonary hypertension from respiratory disease and/or oxygen deficiency

Pulmonary hypertension can also occur in connection with certain respiratory diseases that are associated with a reduced oxygen supply (hypoxemia). In addition, the pulmonary vessels change. These include, for example:

• Chronic obstructive pulmonary disease(COPD)
• Pulmonary fibrosis
• Sleep-associated breathing disorder with other hypoxemic lung disease

Chronic thromboembolic pulmonary hypertension (CTEPH)

The abbreviation CTEPH stands for a disease that can occur as scarred constrictions of the pulmonary vessels following pulmonary embolisms. In a pulmonary embolism, one or more pulmonary arteries become blocked by a blood clot (thrombus). Normally, the blood clot dissolves again through blood thinning. If this process is not complete, scars can form on the vessel wall. This causes the blood vessels to constrict and pulmonary hypertension develops. Chronic thromboembolic pulmonary hypertension is the name of the disease. Some patients develop such scarring even without a previous pulmonary embolism.

It is imperative that this form of PH is correctly diagnosed, as it can be massively improved by surgery and cured except for the need for permanent blood thinning. If surgery is not possible, interventional or drug therapies are also available.

Pulmonary hypertension with unclear and/or multifactorial mechanisms

Doctors are also aware of other diseases that are associated with pulmonary hypertension. These include blood and metabolic diseases. The pulmonary vessels also change here.

Symptoms: Pulmonary hypertension often causes shortness of breath

The symptoms of pulmonary hypertension can vary in severity and severity, depending on the cause of the pulmonary hypertension. The following complaints occur most frequently:

• Shortness of breath, especially during physical exertion such as climbing stairs
• Tiredness, exhaustion, fatigue
• Decrease in physical performance
• Tightness in the chest
• Blue coloration of lips, skin and fingertips (cyanosis) due to lack of oxygen
• Cardiac arrhythmias
• Rapid heartbeat, palpitations
• Thickened neck veins
• Water retention in the tissue (oedema), for example in the legs, ankles or abdomen
• Dizziness
• Circulatory collapse, fainting

Always visit us if you have such symptoms. We can find out what is behind the complaints. The earlier we detect pulmonary hypertension, the easier it is to treat.

Pulmonary hypertension: diagnosis with us

Pulmonary hypertension is a rare disease that is not easy to diagnose. This is because many heart and respiratory diseases are accompanied by similar symptoms. It often takes some time before a diagnosis is made. The diagnosis of pulmonary hypertension always begins with a discussion of your medical history (anamnesis), in which we ask you a few questions. Examples are:

• What symptoms have you noticed?
• When did you first notice them and how intense are they?
• Do the symptoms get worse or better in some situations?
• Do you have any known underlying diseases?
• Are there any diseases in your family? If yes: Which ones?
• Have you ever had a pulmonary embolism?
• Do you have joint problems?
• Are you taking any medications? If yes: Which ones and since when?

Your answers will give us an initial indication of what could be the cause of your complaints. It is also important to exclude or confirm other diseases as causes. This is usually followed by a physical examination. For example, we listen to the lungs and heart. The following diagnostic methods provide further information:

• Exercise test: It is extremely important that we examine your exercise capacity by means of a walking test or cycle ergometer test. The drop in oxygen saturation, e.g. when climbing stairs or during any kind of exertion, can provide important information.
• Cardiac ultrasound through the chest (transthoracic echocardiography shows the condition of the heart and uncovers possible problems.
• Computed tomography (CT): An X-ray examination in which radiologists create detailed cross-sectional images.
• Electrocardiography (ECG): We measure the heart currents. However, a normal ECG does not rule out pulmonary hypertension.
• X-ray examination of the chest (chest X-ray): X-ray images are often informative, but not in every case. Pulmonary hypertension may exist despite inconspicuous images.
• Right heart catheterization: The doctor inserts a catheter from the jugular vein (or groin) via the right heart cavities into the pulmonary artery. This means that blood flow and blood pressure can be measured directly there. As part of the examination, we can also check whether the pulmonary vessels can be dilated by administering medication. Vasoreactivity is the technical term for the method.
• Blood test: The venous blood values can indicate whether you may have concomitant disorders of other organs. Individual values in the blood also indicate the strain on the heart. Arterial blood gas analysis is also important in cases of pulmonary hypertension, as it usually shows hyperventilation.
• Pulmonary function test, In addition to the small lung function (spirometry) for the differential diagnosis of obstructive ventilation disorders, the measurement of lung diffusion capacity is very important for pulmonary hypertension. It shows disturbances in gas exchange.

Pulmonary hypertension – different degrees of severity

Once pulmonary hypertension has been diagnosed, doctors classify the disease into different degrees of severity (NYHA classification according to the New York Heart Association). The decisive factor is the extent to which physical activity is restricted and whether symptoms occur.

• Class I: No effects on physical activity, no typical symptoms such as shortness of breath present
• Class II: Physical activity is slightly restricted. Discomfort during everyday tasks, but not at rest
• Class III: Significant restriction of physical activity, even light activities cause discomfort, but no symptoms at rest; oxygen saturation at approx. 60 percent – treatment is required
• Class IV: Right heart failure, no physical activity is possible, symptoms are already present at rest.

Pulmonary hypertension: prevention, early detection, prognosis

There are no special measures for the prevention and early detection of pulmonary hypertension. If a patient has a genetic form of the disease, family members can be examined and should always consult us if they notice the slightest symptoms.

Pulmonary hypertension – course and prognosis

Pulmonary hypertension is a chronic disease that progresses without treatment. The earlier doctors diagnose pulmonary hypertension, the better the disease can be treated and the more favorable the prognosis. In this way, consequential damage from the disease can often be prevented in good time. Without adequate treatment by experienced doctors, life expectancy is shortened.

Self-help groups

The exchange with people who are affected by the same disease can be a great support in coping with the disease. Advice on finding a suitable self-help group is available from Selbsthilfe Zürich. Self-Help Zurich and the University Hospital Zurich are cooperation partners in the national project “Health literacy thanks to self-help-friendly hospitals”.

Pulmonary hypertension: treatment in special centers

The treatment of pulmonary hypertension belongs in the hands of specialists who have experience with the disease. This is because the therapy is complex and doctors have to tailor it to each patient individually – depending on the cause and symptoms. There are now specialist centers for pulmonary hypertension, known as PH centers.

The aim of treatment is to alleviate the symptoms, halt the progression of the disease and maintain as good a quality of life as possible. Otherwise your physical performance will continue to decline. There are various treatment options. Which ones are suitable always depends on the cause of the pulmonary hypertension. Doctors often treat the underlying disease associated with pulmonary hypertension first.