Figure 2.

Variability in sinus rhythm origin recorded using epicardial mapping in subjects undergoing open‐chest surgery for Wolff‐Parkinson‐White syndrome (adapted from Boineau et al. ²⁰ with permission). Isochronal maps illustrate the propagation of atrial depolarization via either Bachmann's bundle anteriorly (left panel) or via the inferior route beneath the inferior pulmonary veins (right panel). Examples of P waves from lead aVF illustrate the impact of sinus rhythm origin and propagation route on P‐wave morphology.