Catheterisation data with acute vasodilator testing (AVT) for syncope patient responders versus non-responders using Barst criteria
| n | AVT responders# | n | AVT negative with syncope at diagnosis¶ | n | AVT negative with syncope on medications+ | p-value | |
| Room air | |||||||
| Mean RAP mmHg | 6.5 (3–11) | 7 (5–9) | 9 (8–10) | 0.36 | |||
| Mean PAP mmHg | 49 (32–66) | 57 (43–70) | 67 (61–81) | 0.12 | |||
| PVRi WU·m2 | 11.1 (8.6–22) | 16.3 (8.7–26) | 6 | 20.0 (7.8–26.3) | 0.80 | ||
| Rp/Rs | 11 | 0.7 (0.4–1) | 20 | 0.9 (0.7–1) | 6 | 1.3 (0.7–2.4) | 0.14 |
| CI L·min−1·m−2 | 2.8 (2.3–3.9) | 20 | 2.98 (1.9–3.6) | 3.8 (2.2–4.4) | 0.45 | ||
| AVT with iNO | |||||||
| Mean RAP mmHg | 9 | 6 (4–7) | 15 | 8 (5–9) | 6 | 9.5 (7.3–10.3) | 0.07 |
| Mean PAP mmHg | 28 (20–31)§ | 58 (41–77) | 64 (61–82) | 0.0003 | |||
| PVRi WU·m2 | 12 | 5.1 (3.8–8.0)§ | 16.5 (9.3–22.7) | 5 | 22.5 (7.5–26.9) | 0.002 | |
| Rp/Rs | 7 | 0.2 (0.2–0.4)§ | 13 | 0.7 (0.5–1.1) | 5 | 1.1 (0.5–2.3) | 0.0015 |
| CI L·min−1·m−2 | 3.3 (2.6–3.9) | 20 | 3.3 (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.