Several options exist, but they are expensive and necessitate specialist care

For understandable reasons, the pulmonary circulation remains an enigma to most doctors. This is because the cardinal symptom, dyspnoea, is shared with many more common diseases, and the signs of pulmonary hypertension are difficult to elicit for the non-specialist. Consequently, the delay between onset of symptoms and diagnosis is two years, and the mean survival from the time of diagnosis is only another two years in untreated patients with severe hypertension of the pulmonary artery. In the past, pulmonary hypertension was not treatable, but now several treatments are available.

Severe pulmonary hypertension, with a total prevalence of about 30-50/million, can be primary or associated with apparently disparate conditions including connective tissue disease, congenital heart disease, chronic pulmonary thromboembolism, HIV infection, use of an appetite suppressant, and liver disease. Surprisingly, nearly all these conditions have a similar histological picture of vascular remodelling. The pathobiology of pulmonary artery hypertension is now better understood. A gene for familial pulmonary arterial hypertension, which codes for BMPR2 a receptor in the transforming growth factor β (TGF-β) family, has been discovered. 1 2 This gene is also found in up to 26% of patients with so called sporadic pulmonary hypertension. The genetic abnormality perhaps must be accompanied by some additional environmental factor to cause pulmonary artery hypertension (“the double hit hypothesis”), and the remodelling occurs because that factor (or factors) acts in concert with disturbed BMPR signalling to cause an increase in production of cytokines and other factors.

In the …