Table 1 Evolution of the features based on cardiac time intervals throughout the study

From: Evidence of effective cardiovascular countermeasures during spaceflights: insights from wearable monitoring

 

BDC sitting

n = 17

F6

n = 17

F37

n = 17

F159

n = 17

R + 3 sitting

n = 15

R + 8 sitting

n = 17

HR (bpm)

66 [61,75]

61 [56,67]*

62 [54,68]*

61 [60,69]

79 [70,81]*

71 [67,76]*

PEP (ms)

95 [83,99]

87 [81,95]*

88 [75,97]*

85 [79,95]*

87 [80,100]

87 [77, 105]

PEPi (-)

117 [113, 125]

111 [106, 120]*

112 [101, 121]*

114 [120, 106]*

118 [110, 130]

111 [107, 134]

LVET (ms)

304 [286, 330]

324 [312, 348]

327 [318, 357]

334 [318, 359]

334 [318, 359]

300 [271, 316]

LVETi (-)

421 [409, 438]

427 [416, 448]

436 [418, 476]

438 [424, 467]

429 [402, 438]

429 [404, 446]

PEP/LVET (-)

0.29 [0.26, 0.33]

0.27 [0.23, 0.29]*

0.25 [0.22, 0.28]*

0.26 [0.23, 0.28]*

0.31 [0.26, 0.32]

0.29 [0.23, 0.33]

IVCT (ms)

59 [55,71]

60 [50,65]

52 [49,68]

53 [51,66]

55 [53,63]

52 [48,61]

IVRT (ms)

26 [24,30]

22 [20,26]

23 [20,25]

24 [20,28]

26 [18,31]

29 [22,32]

MPI (-)

0.29 [0.24, 0.35]

0.25 [0.21, 0.28]*

0.23 [0.20, 0.27]*

0.24 [0.21, 0.28]*

0.28 [0.23, 0.33]

0.27 [0.23, 0.32]

  1. Measurements are taken at baseline (BDC), during the flight at day 6 ± 2, 37 ± 4, and 159 ± 4 (F6, F37, and F159, respectively), as well as during recovery at 3 and 8 days post-flight (R + 3 and R + 8, respectively). Comparisons are made relative to baseline values in the sitting position using a linear mixed-effects model with Holm-Sidak correction for multiple comparisons. Results are presented as median [first quartile; third quartile].
  2. HR heart rate, PEP pre-ejection period, PEPi pre-ejection period index (-), LVET left ventricular ejection time, LVETi left ventricular ejection time index, IVCT isovolumetric contraction time, IVRT isovolumetric relaxation time, MPI myocardial performance index.
  3. *: p < 0.05.
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