Table 5. Results of heart rate variability analysis.

	Takotsubo	Controls	p-value
SDNN	61 [30–92]	76 [38–114]	0.21
SDNN pre	45 [17–73]	49 [22–77]	0.38
SDNN stress	65 [30–100]	64 [28–100]	0.5
SDNN pre-stressΔ	22 [−14–53]	20 [−21–64]	0.002*
SDNN post	49 [14–83]	56 [24–87]	0.25
SDANN	41 [11–70]	47 [20–73]	0.19
SDANN pre	11 [3]–[19]	16 [−5–27]	0.11
SDANN stress	43 [−5–90]	45 [10–81]	0.74
SDANN post	23 [−18–64]	26 [5–47]	0.65
SDNN pre-stressΔ no BB	39 [6–72]	18 [−18–54]	0.055

Median values in milliseconds [interquartile range]. SDNN; standard deviation of all normal (NN) intervals measured between consecutive sinus beats, SDANN; standard deviation of the average NN intervals, Pre, stress and post; pre-stress, during stress and post-stress measurements, BB; beta-blocker, *p-value for difference within each group.

The non-parametric Mann-Whitney U-test was used to compare the median values for the two independent groups. Wilcoxon Signed Rank test was used to compare the median value within each group.