[The assessment of pulmonary arterial pressure by pulsed Doppler in patients with obstructive pneumopathy]

The severity of pulmonary arterial hypertension can be assessed by duplex-Doppler echocardiography, a subxiphoid approach and a general-purpose duplex device. Normally, the peak Doppler flow velocity occurs in midsystole and the flow profile is parabolic (bullet-like). In pulmonary arterial hypertension, changes in vascular compliance cause maximal acceleration of blood in early systole, with shortening of pulmonary acceleration time (AcT, or time to peak velocity). In the more severe cases, a midsystolic notching is visible, related to rapid deceleration of blood flow, followed by a brief secondary increase in velocity in the late systole. We studied 19 adult patients with chronic obstructive pulmonary disease with duplex-Doppler examination, with a subxiphoid approach and right heart catheterization. The study was diagnostic in all cases with Doppler recordings of good quality. An relationship was found between AcT and pulmonary mean or systolic arterial pressure at rest. An evident accurate prediction of pulmonary arterial pressure in emphysematous patients is possible by means of pulsed Doppler, also in case of low-level hypertension. We believe this method to be a simple and reliable adjunct to the non-invasive work-up of emphysematous patients and to represent a good alternative to the classical parasternal approach, which is often not feasible in these patients.