Table 3.
Right 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 | |||
|---|---|---|---|---|---|---|---|---|---|
| Low-altitude | High-altitude | Low-altitude | High-altitude | Low-altitude | High-altitude | ||||
| 2D and Doppler echocardiography (n = 77/80/83) | |||||||||
| RV EDAi (cm2/m2) | 13.6 (12.2, 15.0) | 12.2 (11.1, 14.0) | < 0.001 | 14.1 (12.7, 15.3) | 13.1 (11.2, 15.1) | 0.007 | 12.8 (11.2, 14.9) | 12.0 (10.9, 13.7) | 0.016 |
| RV ESAi (cm2/m2) | 7.7 (6.9, 8.3) | 7.0 (6.6, 8.4) | 0.036 | 7.4 (6.7, 8.6) | 7.9 (6.4, 8.8) | 0.988 | 7.2 (6.0, 8.1) | 7.0 (5.8, 8.0) | 0.602 |
| RV FAC (%) | 44.0 (42.1, 48.2) | 42.0 (38.6, 44.0) | < 0.001 | 45.9 (42.7, 48.8) | 40.6 (37.5, 44.2) | < 0.001 | 45.5 (41.9, 47.8) | 42.0 (39.1, 45.5) | < 0.001 |
| Tricuspid E (cm/s) | 75.4 ± 11.1 | 62.4 ± 13.4 | < 0.001 | 73.4 ± 12.0 | 61.5 ± 12.0 | < 0.001 | 73.6 ± 15.2 | 61.8 ± 12.9 | < 0.001 |
| Tricuspid A (cm/s) | 34.3 (29.3, 41.3) | 31.0 (24.9, 39.0) | 0.100 | 35.5 (29.7, 39.5) | 31.1 (27.7, 37.3) | 0.018 | 38.5 (33.1, 48.3) | 35.7 (31.4, 41.7) | 0.006 |
| Tricuspid E/A ratio | 2.18 (1.84, 2.53) | 2.00 (1.52, 2.42) | 0.038 | 2.07 (1.67, 2.52) | 1.84 (1.54, 2.28) | 0.016 | 1.86 (1.51, 2.21) | 1.62 (1.40, 2.02) | 0.032 |
| Color tissue doppler imaging (n = 43/47/57) | |||||||||
| Tricuspid S′ (cm/s) | 7.9 ± 1.2 | 7.7 ± 1.4 | 0.515 | 7.7 ± 1.7 | 7.7 ± 1.2 | 0.990 | 7.6 ± 1.6 | 7.3 ± 1.4 | 0.169 |
| Tricuspid E′ (cm/s) | 7.1 (5.7, 8.4) | 7.6 (5.8, 9.1) | 0.284 | 7.1 (5.4, 8.7) | 7.8 (6.5, 9.0) | 0.105 | 7.3 (5.2, 8.4) | 7.2 (5.6, 8.8) | 0.646 |
| Tricuspid E/E′ ratio | 10.6 (8.4, 12.8) | 8.1 (6.3, 10.4) | 0.009 | 10.4 (8.7, 14.2) | 7.8 (6.7, 9.8) | < 0.001 | 10.1 (8.5, 12.9) | 8.8 (7.4, 12.0) | 0.034 |
| RV MPI | 0.53 (0.40, 0.67) | 0.63 (0.52, 0.81) | 0.004 | 0.58 (0.47, 0.74) | 0.64 (0.48, 0.75) | 0.342 | 0.49 (0.33, 0.63) | 0.63 (0.45, 0.75) | 0.004 |
| Pulmonary haemodynamics (n = 77/80/83) | |||||||||
| AT/ET | 0.38 (0.34, 0.40) | 0.31 (0.28, 0.35) | < 0.001 | 0.37 (0.34, 0.41) | 0.31 (0.26, 0.35) | < 0.001 | 0.37 (0.35, 0.40) | 0.32 (0.27, 0.35) | < 0.001 |
| mPAP, mmHg | 16.9 (12.4, 21.3) | 24.3 (20.1, 29.9) | < 0.001 | 18.6 (15.6, 22.1) | 23.1 (20.0, 33.5) | < 0.001 | 19.7 (16.9, 22.7) | 24.2 (20.4, 33.8) | < 0.001 |
| TR [n (%)] | 38 (49.4) | 61 (79.2) | < 0.001 | 48 (60.0) | 68 (85.0) | < 0.001 | 49 (59.0) | 63 (75.9) | 0.020 |
| TRV (m/s) | 2.15 (2.05, 2.33) | 2.54 (2.26, 2.83) | < 0.001 | 2.10 (1.92, 2.35) | 2.45 (2.24, 2.73) | < 0.001 | 2.15 (1.87, 2.33) | 2.43 (2.30, 2.73) | < 0.001 |
| SPAP (mmHg) | 28.5 (26.9, 31.8) | 35.7 (30.4, 42.1) | < 0.001 | 27.7 (24.7, 32.1) | 34.0 (30.1, 39.8) | < 0.001 | 28.4 (24.0, 31.6) | 33.7 (31.1, 39.9) | < 0.001 |
Values are median (25th to 75th quartile) or mean ± SD
Abbreviations as in Table 1