Pulmonary Hypertension

Pulmonary hypertension (PH) is an increase in pressure within the blood vessels of the lungs. It is not a single condition and can occur for a number of different reasons, including diseases affecting the pulmonary blood vessels themselves, the left side of the heart, the lungs, or as a consequence of chronic blood clots in the pulmonary arteries.

I have a longstanding clinical and academic interest in pulmonary hypertension and pulmonary vascular disease. I assess patients with suspected or established pulmonary hypertension, as well as people with unexplained breathlessness in whom a problem with the pulmonary circulation may be contributing to their symptoms.

Pulmonary hypertension can be difficult to recognise because its symptoms overlap with many other heart and lung conditions. Breathlessness is the most common symptom, particularly during exercise, but people may also notice reduced exercise capacity, fatigue, dizziness, palpitations or chest discomfort.

Assessment may be helpful if you have:

• unexplained or progressive breathlessness
• an echocardiogram suggesting raised pulmonary pressures or changes affecting the right side of the heart
• unexplained enlargement of the pulmonary arteries or right heart on imaging
• persistent breathlessness following a pulmonary embolism
• a medical condition associated with an increased risk of pulmonary hypertension
• an established diagnosis of pulmonary hypertension where further review or a second opinion would be helpful.

One common reason for referral is an echocardiogram that has suggested possible pulmonary hypertension.

An echocardiogram is extremely useful, but it does not diagnose pulmonary hypertension on its own. It provides information about the probability of pulmonary hypertension and about the structure and function of the heart, particularly the right ventricle.

I will review your symptoms, previous medical history and existing investigations in detail. The aim is not simply to determine whether pulmonary pressures may be elevated, but to understand why this might be happening and whether further investigation is necessary.

Depending on the individual clinical picture, assessment may include:

• ECG and echocardiography
• Lung function testing
• Blood tests
• CT imaging
• Ventilation/perfusion (V/Q) scanning
• Cardiopulmonary exercise testing (CPET).

Not everyone requires all of these tests. Investigations are selected according to the individual patient and the information already available.

Pulmonary vascular disease is particularly relevant to the investigation of unexplained breathlessness.

Some abnormalities of the pulmonary circulation may become most apparent during physical activity. In selected patients, cardiopulmonary exercise testing (CPET) can therefore provide additional information about how the heart, lungs and circulation respond during exercise.

CPET does not diagnose pulmonary hypertension by itself, but it can help identify patterns of physiological limitation and determine whether further cardiovascular, respiratory or pulmonary vascular investigation is appropriate.

If your assessment suggests that pulmonary hypertension may be present, the next step depends on the likely cause, the results of your investigations and the degree of clinical suspicion.

An echocardiogram can provide important information about the probability of pulmonary hypertension and the function of the right side of the heart, but it cannot confirm the diagnosis on its own.

Where pulmonary arterial hypertension, chronic thromboembolic pulmonary hypertension or another significant pulmonary vascular condition is suspected, further assessment within a specialist pulmonary hypertension service may be required.

Right-heart catheterisation is the gold-standard investigation for confirming and haemodynamically classifying pulmonary hypertension. This directly measures the pressures within the right side of the heart and pulmonary circulation, as well as blood flow through the heart, and allows the type and severity of pulmonary hypertension to be assessed accurately.

Where specialist investigation is appropriate, I can help coordinate referral to a specialist pulmonary hypertension service.

I also see patients who already have a diagnosis of pulmonary hypertension and would like their diagnosis, symptoms or investigations reviewed.

There are several different forms of pulmonary hypertension and treatment depends very significantly on the underlying cause. A careful review of the original diagnosis, haemodynamic measurements, imaging and other investigations can therefore be valuable when considering the overall clinical picture.

Pulmonary hypertension is classified into five main groups, and these have different causes and treatments. Treatment appropriate for one form of pulmonary hypertension may not be appropriate for another.

For a more detailed explanation of the different types of pulmonary hypertension, symptoms, investigations and treatment, read: