**4.6 Vereckei aVR algorithm**

Vereckei et al. published four-step algorithms with the incorporation of new criteria of Vi/Vt (**Figure 5**) [50–64, 71].

The four steps were used in the following sequence:


During WCT due to SVT, after the initial rapid septal activation over the normal His-Purkinje system, the slow intraventricular activation occurs in the mid to terminal portion of the QRS, thus the Vi/Vt > 1.
