Table 6.

Intra- and inter-observer variability of systolic RVFW-LSR

	Intra-observer variability			Inter-observer variability
	MD ± SD	ICC (95% CI)	CoV	MD ± SD	ICC (95% CI)	CoV
RVFW-GLSRs	0.25 ± 0.32	0.94 (0.83–0.98)	16.99	0.30 ± 0.28	0.94 (0.82–0.98)	15.30
RVFW-RLSRs
Basal	0.36 ± 0.50	0.94 (0.82–0.98)	15.65	0.70 ± 0.59	0.75 (0.26–0.92)	19.13
Middle-cavity	0.37 ± 0.31	0.92 (0.76–0.97)	11.47	0.41 ± 0.38	0.92 (0.75–0.97)	13.98
Apical	0.35 ± 0.39	0.91 (0.74–0.97)	18.62	0.49 ± 0.35	0.83 (0.49–0.94)	16.13
RVFW-SLSRs
Segment 1	0.65 ± 0.76	0.91 (0.74–0.97)	20.96	1.07 ± 0.96	0.62 (− 0.12–0.87)	27.91
Segment 2	0.48 ± 0.51	0.92 (0.76–0.97)	18.06	0.72 ± 0.54	0.79 (0.37–0.93)	19.99
Segment 3	0.54 ± 0.46	0.87 (0.61–0.96)	16.76	0.56 ± 0.49	0.90 (0.69–0.97)	17.24
Segment 4	0.40 ± 0.42	0.89 (0.67–0.97)	15.85	0.47 ± 0.42	0.89 (0.67–0.97)	15.78
Segment 5	0.53 ± 0.56	0.83 (0.49–0.94)	22.91	0.80 ± 0.70	0.61 (− 0.15–0.87)	27.99
Segment 6	0.44 ± 0.36	0.79 (0.33–0.93)	23.31	0.58 ± 0.39	0.62 (− 0.17–0.88)	23.28

GLSRs global longitudinal systolic peak strain rate, RLSRs regional longitudinal systolic peak strain rate, SLSRs segmental longitudinal systolic peak strain rate, MD mean difference, SD standard deviation, ICC intra-class correlation coefficient, CI confidence interval, CoV coefficient of variation. The unit of CoV is %