The early symptoms of pulmonary arterial hypertension (PAH), such as dyspnea, dizziness, and fatigue, are often mild and are common to many other conditions. At rest there are often no symptoms and no apparent signs of illness. As a result, time from symptom onset to disease diagnosis is, on average, more than 2 years. This means that PAH is frequently not recognized until the disease is relatively advanced. In addition, PAH is a challenging disease to diagnose accurately. It requires invasive investigations and significant experience to manage patients effectively. As such, current guidelines recommend that the patients should be referred to expert centers experienced in the management of pulmonary vascular diseases. The organization of delivery of healthcare services for PAH varies across countries, therefore it is recommended that you contact your national healthcare service or PAH patient organization to understand how recommendations from the guidelines are being implemented in your region.
Once a suspicion of PAH has been raised, the aim is to confirm or exclude a diagnosis of pulmonary hypertension (PH) and, if present, establish its etiology, assess disease severity, as well as to decide on subsequent management and treatment strategies.
The non-specific nature of symptoms associated with PAH means that the diagnosis cannot be made on symptoms alone. Diagnosis involves a logical sequence of steps. These diagnostic steps have been formalized into clinical practice guidelines for the diagnosis of PAH, both in the US and Europe. The evaluation process of a patient with suspected PAH involves a series of investigations to determine whether there is a likelihood of PAH being present, to confirm the diagnosis based on initial non-invasive testing, to clarify the specific etiology, to evaluate the functional and hemodynamic impairment of the individual patient, and to determine an appropriate treatment category. Although there are slight differences in the sequence of tests performed, the nature and overall flow is similar in both sets of guidelines. Interpretation of the results of tests described below is complex and requires substantial experience in the management and follow-up of PAH patients.