Table 4.
Group 2 POTS with HR Increase of 30–39 bpm at End-Tilt (n= 145) | Group 3 POTS with HR Increase of ≥40 bpm at End-Tilt (n = 88) | t Test/Mann–Whitney U Test: p-Value | |
---|---|---|---|
supine HR (bpm) | 74 (12) | 75 (12) | p = 0.48 |
end-tilt HR (bpm) | 105 (98–114) | 121 (113–132) | p < 0.001 |
delta HR (bpm) | 33 (3) | 48 (7) | p < 0.001 |
supine SVI (mL/m2) | 38 (5) | 36 (7) | p = 0.119 |
end-tilt SVI (mL/m2) | 18 (17–20) | 20 (17–23) | p = 0.005 |
delta SVI (mL/m2) | −19 (4) | −16 (5) | p < 0.001 |
supine CI (L/min/m2) | 2.75 (0.49) | 2.69 (0.48) | p = 0.366 |
end-tilt CI (L/min/m2) | 1.93 (1.71–2.17) | 2.53 (2.21–2.90) | p < 0.001 |
delta CI (L/min/m 2) | −0.77 (0.24) | −0.12 (0.28) | p < 0.001 |
supine SBP (mmHg) | 132 (15) | 133 (15) | p = 0.647 |
end-tilt SBP (mmHg) | 128 (18) | 127 (19) | p = 0.874 |
supine DBP (mmHg) | 80 (11) | 80 (8) | p = 0.672 |
end-tilt DBP (mmHg) | 89 (14) | 87 (13) | p = 0.314 |
SBP: systolic blood pressure; DBP: diastolic blood pressure HR: heart rate; POTS: postural orthostatic tachycardia syndrome; SVI: stroke volume index. CI: cardiac index.