Table 3.

Within-beat variability of 3 index-beats versus 3, 5 and 10 consecutive beats

	LVEF Simpson’s biplane		GLS		E/e’
	Coefficient of variation, % (95% CI)	Intraclass correlation coefficient (95% CI)	Coefficient of variation, % (95% CI)	Intraclass correlation coefficient (95% CI)	Coefficient of variation, % (95% CI)	Intraclass correlation coefficient (95% CI)
3 index-beats	32 (31 to 34)	0.94 (0.93 to 0.96)	26 (25 to 27)	0.88 (0.85 to 0.91)	25 (24 to 26)	0.96 (0.95 to 0.97)
3 consecutive beats	54 (52 to 57)	0.71 (0.64 to 0.77)	44 (42 to 46)	0.81 (0.76 to 0.85)	40 (37 to 41)	0.81 (0.76 to 0.85)
5 consecutive beats	51 (50 to 53)	0.76 (0.71 to 0.81)	43 (42 to 44)	0.82 (0.77 to 0.85)	41 (40 to 43)	0.77 (0.72 to 0.81)
10 consecutive beats	53 (52 to 54)	0.74 (0.69 to 0.79)	42 (41 to 43)	0.80 (0.75 to 0.84)	41 (41 to 42)	0.78 (0.73 to 0.81)

E/e', mitral E wave max/average diastolic tissue Doppler velocity from the septal and lateral annulus; GLS, global longitudinal strain; LVEF, left ventricular ejection fraction.