Catheterisation data with acute vasodilator testing (AVT) for syncope patient responders versus non-responders using Barst criteria

nAVT responders#nAVT negative with syncope at diagnosisnAVT negative with syncope on medications+p-value
Room air
 Mean RAP mmHg6.5 (3–11)7 (5–9)9 (8–10)0.36
 Mean PAP mmHg49 (32–66)57 (43–70)67 (61–81)0.12
 PVRi WU·m211.1 (8.6–22)16.3 (8.7–26)620.0 (7.8–26.3)0.80
 Rp/Rs110.7 (0.4–1)200.9 (0.7–1)61.3 (0.7–2.4)0.14
 CI L·min−1·m−22.8 (2.3–3.9)202.98 (1.9–3.6)3.8 (2.2–4.4)0.45
AVT with iNO
 Mean RAP mmHg96 (4–7)158 (5–9)69.5 (7.3–10.3)0.07
 Mean PAP mmHg28 (20–31)§58 (41–77)64 (61–82)0.0003
 PVRi WU·m2125.1 (3.8–8.0)§16.5 (9.3–22.7)522.5 (7.5–26.9)0.002
 Rp/Rs70.2 (0.2–0.4)§130.7 (0.5–1.1)51.1 (0.5–2.3)0.0015
 CI L·min−1·m−23.3 (2.6–3.9)203.3 (2.2–3.8)3.4 (2.4–4.2)0.72

Data are expressed as median (interquartile range). Bold p-values represent statistically significant differences between AVT responders and AVT negative. One patient who responded to AVT on her initial catheterisation (included in that category in table 1) lost AVT response by time of syncope as reflected in her later catheterisation used here. RAP: right atrial pressure; PAP: pulmonary artery pressure; PVRi: indexed pulmonary vascular resistance; Rp/Rs: ratio of pulmonary vascular resistance/systemic vascular resistance; CI: cardiac index; iNO: inhaled nitric oxide. #: n=14; : n=21; +: n=7; §: represents statistically significant differences on room air compared to AVT.