Research Article

Changes in Heart Rate Variability of Depressed Patients after Electroconvulsive Therapy

Table 3

Depression and heart rate variability measures of study participants before ECT-1 and before ECT-6.

Parameterbefore ECT-1 (mean ± SD)before ECT-6 (mean ± SD)Change (mean ± SD) 𝑃 valuea

BDI Score
 ECT responders 3 7 . 7 ± 9 . 8 1 2 . 5 ± 8 . 7 2 5 . 2 ± 7 . 6 <0.0001
 ECT nonresponders 3 3 . 7 ± 1 0 . 9 2 6 . 7 ± 6 . 9 7 . 0 ± 7 . 4
Heart Rate (bpm)
 ECT responders 7 5 . 7 ± 5 . 9 7 6 . 4 ± 6 . 7 0 . 6 ± 5 . 1 0.21
 ECT nonresponders 7 5 . 8 ± 1 5 . 8 7 3 . 5 ± 1 4 . 8 2 . 2 ± 5 . 1
RMSDD (ms)
 Responders 2 5 . 7 ± 7 . 1 2 3 . 7 ± 1 2 . 7 2 . 0 ± 1 1 . 9 0.26
 Nonresponders 2 0 . 0 ± 1 0 . 9 2 3 . 3 ± 1 2 . 8 3 . 3 ± 8 . 9
LF (ms2)
 ECT responders 9 1 8 . 5 ± 6 1 5 . 7 7 9 1 . 3 ± 5 8 9 . 0 1 2 7 ± 5 6 2 . 8 0.88
 ECT nonresponders 6 5 5 . 9 ± 8 0 4 . 5 4 8 1 . 8 ± 4 2 1 . 1 1 7 4 ± 7 6 9 . 3
HF (ms2)
 ECT responders 2 2 3 . 9 ± 1 6 0 . 5 2 4 6 . 4 ± 3 0 1 . 1 2 2 . 5 ± 2 9 4 . 0 0.98
 ECT nonresponders 1 8 3 . 6 ± 2 3 4 . 8 2 0 2 . 8 ± 2 2 3 . 3 1 9 . 2 ± 2 0 4 . 4
LF/HF
 ECT responders 4 . 7 7 ± 2 . 2 7 5 . 3 2 ± 3 . 0 3 0 . 5 5 ± 2 . 7 1 0.21
 ECT nonresponders 5 . 3 9 ± 5 . 3 8 4 . 3 4 ± 3 . 5 8 1 . 0 5 ± 2 . 9 3
SD1
 ECT responders 1 8 . 2 ± 5 . 0 1 6 . 7 ± 9 . 0 1 . 4 ± 8 . 4 0.26
 ECT nonresponders 1 4 . 2 ± 7 . 7 1 6 . 5 ± 9 . 1 2 . 3 ± 6 . 4
SD2
 ECT responders 6 6 . 2 ± 2 3 . 2 6 5 . 1 ± 2 0 . 1 1 . 1 ± 2 3 . 6 0.88
 ECT nonresponders 5 0 . 1 ± 2 9 . 1 5 0 . 7 ± 1 7 . 0 0 . 6 ± 2 5 . 9
SD1/SD2
 ECT responders 0 . 2 8 ± 0 . 0 7 0 . 2 7 ± 0 . 1 4 0 . 0 2 ± 0 . 1 1 0.37
 ECT nonresponders 0 . 3 0 ± 0 . 1 1 0 . 3 3 ± 0 . 1 5 0 . 0 3 ± 0 . 1 4

a 𝑃 values are based on comparisons of the change between ECT-1 and ECT-6 in ECT responders and ECT nonresponders.
ECT: electroconvulsive therapy; BDI: Beck Depression Inventory; RMSDD: root mean square of successive differences; LF: power in the low-frequency range (0.04–0.15 Hz); HF: power in the high-frequency range (0.15–0.4 Hz); SD1: standard deviation of the distances of points from the 𝑦 - 𝑥 axes.