Primary pulmonary hypertension: a continuing diagnostic and therapeutic challenge.

: Primary pulmonary hypertension (PPH) continues to present both diagnostic and therapeutic challenges to the physician, reflecting the lack of understanding about the basic mechanism of the disease. The onset of the condition is usually insidious, the main symptoms of dyspnoea, syncope and angina often being ascribed to functional or emotional causes. As a result, delay in diagnosis is the norm, with an interval from onset of symptoms to diagnosis of up 2 yrs. The ability of the vasodilator drugs that are now available to produce sustained improvement in patients with PPH is limited by a number of factors. The prognosis is generally severe; however, despite the overall dismal prognosis, duration of survival ranges up to 10 years or more. It is important to consider the possibility of an early stage, when functional changes are prevalent in a substantial number of patients with primary pulmonary hypertension. At this stage, an optimized therapy would be expected to interrupt the course of pulmonary hypertension or, at the very least, retard its progression.