Non-invasive assessment of pulmonary arterial hypertension in chronic lung disease (WHO study).

Methods for prolonged recording of pulmonary artery pressure (PAP) in unrestricted subjects have been developed. Although relatively safe, cardiac catheterization is invasive and expensive. By combining several non-invasive methods (NIM) aiming to predict the level of PAP, the extent of right ventricular (RV) hypertrophy and the degree of RV dysfunction, respectively, one can foresee the existence or the absence of pulmonary arterial hypertension (PAH), but not the precise level of PAP. This result is satisfactory in order to screen "at risk" populations, but not to obtain occasional readings from a patient with chronic obstructive lung diseases. In this type of patient PAP increase is not very marked and lung hyperinflation reduces the sensitivity of some NIM and precludes the correct execution of others. Increasing the number of investigation entails an increase of the cost-benefit ratio. NIM may help select risk patients for catheterization for suspected exercise PAH or mild PAH at rest. Some doubts exist as to whether the same methods can be used for exploring the effects of treatment in patients with chronic lung disease.