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. 2018 Dec 6;24(3):e12621. doi: 10.1111/anec.12621

Figure 4.

Figure 4

Intraobserver variation in QRS duration measured in paced and intrinsic rhythm electrocardiograms. Top: Bland–Altman plots illustrating intraobserver variation in two repeated measurements of QRS duration performed by Observers a and b in 20 intrinsic rhythm electrocardiograms. Observer a: limits of agreement (LoA): lower limit (LL) −24 ms (95% confidence interval [CI] −33; −15 ms); upper limit (UL) 19 ms (95% CI 10; 28 ms), Observer b: LoA: LL −13 ms (95% CI −20; −6 ms); UL 22 ms (95% CI 15; 29 ms). Bottom: intraobserver variation in two repeated measurements of QRS duration performed by Observers a and b in 100 paced electrocardiograms. Observer a: LoA: LL −27 ms (95% CI −30; −23 ms); UL 14 ms (95% CI 10; 17 ms), Observer b: LoA: LL −17 ms (95% CI −19; −14 ms); UL 14 ms (95% CI 11; 17 ms). Mean difference between first and second measurement of QRS duration and LoA with 95% CI are shown in all four plots. ECG: electrocardiogram; Obs.: observer; QRSd: QRS duration