Table 2.
Physiologic parameters and Left ventricular parameters of participants in different baseline resting heart rate at sea level and at high altitude
| Variables | Lowest tertile | P value | Middle Tertile | P value | Highest tertile | P value | |||
|---|---|---|---|---|---|---|---|---|---|
| Sea level | High altitude | Sea level | High altitude | Sea level | High altitude | ||||
| Physiologic parameters (n = 77/80/83) | |||||||||
| HR (beats/min) | 56 (53, 58) | 65 (58, 73) | < 0.001 | 64 (62, 66) | 72 (64, 78) | < 0.001 | 75 (70, 79) | 77 (69, 84) | 0.280 |
| SaO2 (%) | 98 (97, 98) | 89 (88, 91) | < 0.001 | 98 (97, 98) | 89 (88, 91) | < 0.001 | 98 (97, 98) | 89 (88, 91) | < 0.001 |
| SBP (mmHg) | 112 (107, 119) | 120 (112, 127) | < 0.001 | 110 (104, 118) | 118 (112, 126) | < 0.001 | 115 (108, 120) | 123 (115, 127) | < 0.001 |
| DBP (mmHg) | 67.0 ± 8.5 | 78.9 ± 8.8 | < 0.001 | 67.3 ± 9.0 | 77.4 ± 8.9 | < 0.001 | 68.4 ± 8.2 | 80.5 ± 9.6 | < 0.001 |
| 2D and Doppler echocardiography (n = 77/80/83) | |||||||||
| LV EDVi (ml/m2) | 57.1 (50.2, 66.3) | 54.2 (44.8, 58.9) | 0.004 | 58.1 (51.1, 65.8) | 52.2 (45.4, 59.6) | < 0.001 | 58.7 (49.2, 67.8) | 49.1 (41.5, 58.9) | < 0.001 |
| LV ESVi (ml/m2) | 22.2 ± 7.6 | 18.4 ± 5.8 | < 0.001 | 22.5 ± 7.1 | 18.9 ± 5.9 | < 0.001 | 22.6 ± 8.8 | 18.0 ± 5.7 | < 0.001 |
| SVI (ml/m2) | 35.9 (30.6, 41.2) | 33.5 (29.1, 39.9) | 0.268 | 35.8 (30.8, 41.5) | 33.2 (28.1, 39.8) | 0.012 | 33.6 (30.0, 44.1) | 30.6 (23.8, 39.0) | 0.004 |
| CI (L/min/m2) | 1.9 (1.6, 2.3) | 2.2 (1.8, 2.6) | < 0.001 | 2.3 (2.0, 2.6) | 2.3 (1.9, 2.8) | 0.568 | 2.5 (2.1, 3.4) | 2.3 (1.8, 3.1) | 0.012 |
| LVEF (%) | 61.7 (56.5, 68.0) | 66.1 (60.7, 71.5) | 0.004 | 61.6 (56.1, 67.5) | 64.6 (58.5, 71.5) | 0.128 | 63.1 (55.7, 69.1) | 64.9 (57.5, 69.3) | 0.112 |
| Mitral E (cm/s) | 99.9 (90.5, 111.8) | 75.2 (68.0, 90.0) | < 0.001 | 96.6 (88.4, 105.4) | 79.5 (68.9, 91.6) | < 0.001 | 99.9 (90.5, 111.8) | 75.2 (68.0, 90.0) | < 0.001 |
| Mitral A (cm/s) | 48.0 ± 11.2 | 46.2 ± 10.1 | 0.324 | 50.4 ± 11.1 | 51.2 ± 11.9 | 0.662 | 56.4 ± 11.3 | 51.3 ± 9.8 | < 0.001 |
| Mitral E/A ratio | 2.16 (1.71, 2.50) | 1.71 (1.47, 2.15) | < 0.001 | 1.89 (1.65, 2.27) | 1.61 (1.31, 1.86) | < 0.001 | 1.78 (1.45, 2.07) | 1.53 (1.33, 1.81) | < 0.001 |
| Color tissue doppler imaging (n = 43/47/57) | |||||||||
| Mitral S′ (cm/s) | 5.8 ± 1.4 | 6.5 ± 1.9 | 0.040 | 5.8 ± 1.6 | 6.5 ± 1.5 | 0.035 | 6.7 ± 1.8 | 6.3 ± 1.5 | 0.167 |
| Mitral E′ (cm/s) | 8.7 ± 2.6 | 8.2 ± 1.9 | 0.262 | 8.9 ± 2.0 | 8.0 ± 2.0 | 0.008 | 9.2 ± 2.0 | 8.4 ± 1.8 | 0.003 |
| Mitral E/E′ ratio | 10.6 (8.6, 13.6) | 8.6 (7.6, 12.4) | 0.058 | 10.7 (9.4, 12.6) | 9.5 (8.6, 11.6) | 0.014 | 10.3 (9.2, 12.0) | 8.7 (7.3, 11.2) | 0.011 |
| LV MPI | 0.42 ± 0.16 | 0.48 ± 0.17 | 0.097 | 0.44 ± 0.12 | 0.51 ± 0.16 | 0.014 | 0.38 ± 0.12 | 0.45 ± 0.14 | 0.001 |
Values are median (25th to 75th quartile) or mean ± SD
Abbreviations as in Table 1