Figure 4
Comparison of QTc mean using Bazett’s, Friedericia’s, and Framingham’s formulas between standard and smartwatch ECG. Bland–Altman plot indicating the level of agreement between the smartwatch ECG and standard 12-lead ECG measurement of QTc (ms) using Bazett’s formula (three panels on the left: (A–C)); Friedericia’s formula (three panels in the center: (D–F)); and Framingham’s formula (three panels on the right: (G–I)), respectively, from the top to the bottom: lead I, lead II, and the V2 lead. The solid red line represents the bias and dashed red lines the upper and lower LOA.
