Effect of Acute Mental Stress on Heart Rate and QT Variability in Postmyocardial Infarction Patients
Table 2
RR and SPB power spectral data and QTVI values obtained from the analysis of the whole 5 min ECG segment in the three study groups.
Variables
LVEF ≤ 45% group N: 20
LVEF ≥ 50% group N: 10
Control group N: 10
ANOVA
LVEF ≤ 45% group N: 20
LVEF ≥ 50% group N: 10
Control group N: 10
ANOVA
Baseline
During Anger Recall test
RR mean, ms
877 ± 145‡
873 ± 86‡
1006 ± 110‡
Ns
848 ± 149
833 ± 97
Ns
SBP mean, mmHg
108 ± 19‡
122 ± 32‡
113 ± 25‡
Ns
119 ± 24
132 ± 34
Ns
SDNN, ms
23 ± 10††
31 ± 12
42 ± 12
<.001
28 ± 14††
37 ± 12
<.001
TPRR, ms2
481 [542]‡††§
977 [799]‡
1814 [1352]
<.001
533 [1183]††§
1456 [1509]
2121 [1628]
<.001
VLFRR, ms2
293 [303]††§
527 [714]
1091 [568]
<.001
209 [339]†§
967 [822]
1030 [3741]
.004
LFRR, ms2
71 [127]ࠤ
233 [315]‡
308 [367]‡
.003
183 [286]††§
411 [755]*
918 [625]
<.001
HFRR, ms2
52 [101]†
51 [127]*
173 [472]†
.006
58 [144]†
94 [93]*
236 [553]
.006
TPSPB, mmHg2
14 [9]ࠤ
26 [21]‡
38 [37]†
.003
33 [21]§
65 [112]
49 [106]
.027
VLFSPB, mmHg2
7 [5]††§
19 [22]‡
30 [33]
<.001
13 [18]§
48 [9]§
21 [73]
.039
LFSPB, mmHg2
2 [3]‡†
4 [3]‡
6 [9]‡
.003
7 [4]†§
13 [9]§
15 [12]
.002
HFSPB, mmHg2
2 [3]‡
2 [1]‡
1 [2]
Ns
4 [5]
4 [5]
2 [4]
Ns
LF CF, Hz
Ns
Ns
HF CF, Hz
Ns
Ns
QTVI
−0.25 [0.67]†§
−0.83 [0.70]
−1.10 [0.55]
.001
−0.37 [0.82]†§
−0.76 [0.44]*
−1.05 [0.23]
<.001
Values are expressed as mean ± SD or median [interquartile range 75th percentile–25th percentile]. TP: total spectral power; VLF: very-low frequency; LF: low frequency; HF: high frequency; CF: central frequency; SBP: systolic blood pressure.
‡ data at baseline versus data after Anger Recall test; †† LVEF ≤ 45% Group versus Controls; † LVEF ≤ 45% Group versus Controls;
§ LVEF ≤ 45% Group versus LVEF ≥ 50% Group; * LVEF ≥ 50% Group versus Controls.
