Acute haemodynamic changes in response to sildenafil#
| Major acute effect group | Minor acute effect group | |
| Subjects n | 35 | 32 |
| ΔP̄pa % | 23±1 | 13±2 |
| ΔPVR % | 34±1 | 12±2 |
Data are presented as mean±sem, unless otherwise stated. Classification of the acute response was according to the degree of reduction in pulmonary vascular resistance (PVR; cut-off 27%). Δ: change; P̄pa: mean pulmonary arterial pressure. #: in a subset of 67 patients.