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Pulmonary Hypertension

What is pulmonary hypertension?

Pulmonary hypertension (PH) is a general term that refers to high blood pressure in the pulmonary arteries, which are the blood vessels that transport blood from the heart to the lungs.

PH is different to regular hypertension, which is high blood pressure in arteries throughout the rest of the body.

There are five groups of PH which are defined by the World Health Organization (WHO) and are referred to as PH WHO Groups.

What are the five PH WHO Groups of pulmonary hypertension?

Group 1: Pulmonary Arterial Hypertension (PAH)

Group 1 PH, or PAH, is due to changes in the cells in the blood vessels in the lungs. This leads to thickening, narrowing, and stiffening of these artery walls, which increases the ‘resistance’ provided by the blood vessels in the lungs, which then leads to PH. can slow blood flow to the lungs.

Major types of PAH include:

Group 2: Pulmonary Hypertension Due to Left Heart Disease

WHO Group 2 PH is the most common type of PH. It can be caused by left heart failure, or left side heart valve disease e.g. mitral valve or aortic valve disease. This causes increased blood pressure due to the left side of the heart being unable to effectively manage the blood returning from the lungs.

Group 3: Pulmonary Hypertension Due to Lung Disease

WHO Group 3 PH is due to chronic lung diseases such as chronic obstructive pulmonary disease or pulmonary fibrosis (scarring of the lungs), as well as long term exposure to high altitudes. These conditions cause increased blood pressure due to tightening of the arteries in the lungs.

Group 4: Pulmonary Hypertension Due to Chronic Blood Clots in the Lungs

WHO Group 4 is also known as chronic thromboembolic pulmonary hypertension (CTEPH) – which means PH due to blood clots in the blood vessels to the lungs. This PH occurs when the body is not able to breakdown blood clots in the lungs, which can lead to restricted blood flow and increased blood pressure.

Group 5: Pulmonary Hypertension Due to Unknown Causes

WHO Group 5 is PH that is secondary to other diseases including blood disorders, inflammatory disorders, metabolic disorders, and kidney disease. Often the causes of this type of PH are not well understood.

What are the symptoms of pulmonary hypertension?

Symptoms of PH can develop over months or even years and may get worse as the disease progresses.

PH symptoms can include:

How is pulmonary hypertension diagnosed?

A very common way that PH may be diagnosed is by echocardiography (echo) when it is performed as part of an investigation into the causes of breathlessness or other symptoms of the disease.

In addition, if PH is suspected or confirmed, your doctor may run the following tests:

When PH is first diagnosed, it is common to perform a right heart catheterisation to directly measure the pressures in the pulmonary arteries and confirm the diagnosis.

How is pulmonary hypertension treated?

Treatment for PH will depend on the WHO group and severity. PH is a serious diagnosis that will require specialist review and care, often in a dedicated clinic that specialises in this disorder.

Treatment may include:

In severe cases, where there is considerable damage to the heart and/or lungs, transplantation may be required.

How can pulmonary hypertension be prevented?

Not all cases of PH can be prevented, although making lifestyle changes and managing conditions that can cause PH may somewhat reduce your risk.

Acknowledgement of Country

The Victor Chang Cardiac Research Institute acknowledges Traditional Owners of Country throughout Australia and recognises the continuing connection to lands, waters and communities. We pay our respect to Aboriginal and Torres Strait Islander cultures; and to Elders past and present.

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