Stress-induced pulmonary hypertension: definition and diagnosis

The first hemodynamic definition of pulmonary hypertension (PH) was given at the World Symposium on PH (WSPH, 1973) in Geneva as an increasebin resting mean pulmonary artery pressure (mPAP) >25 mm Hg by heart chamber catheterization. Since 2004, in the definition of PH, in addition to an increase in resting mPAP, an 'exercise' criterion has also been included: mPAP at the peak of exercise >30 mm Hg. However, at the 4th WSPH Symposium in 2008, due to uncertainty of the relationship between age-related changes in cardiac output (CO) and pulmonary vascular physiology, in particular pulmonary vascular resistance (PVR) under exercise, this criterion was excluded. Resting PH manifests only at the absence of ≥50 % of pulmonary microcirculation, so for the earliest diagnosis of the disease, it’s necessary to use factors that provoke an increase in CO and PVR. Moreover, in clinical practice, manifestations of PH are not uncommon on exercise. In the absence of consensus the definition of stress- induced PH is defined in individuals with normal mPAP (< 25 mm Hg) at rest and elevated mPAP (>30 mm Hg) and PVR> 3 WU at the peak of exercise.