Figure 1. Episodes of RBBB pattern PMA in ambulatory ECG monitoring. The retrograde P waves were marked by black triangles. (A) One episode of PMA was triggered by the third PVC. Sinus P waves were marked by blue arrows. (B) Another episode of PMA was triggered by a PAC (hollow triangle) accompanied by the appearance of VA conduction with no prolongation of AV delay. (C) Every episode of PMA was self-terminated by a short-coupling PVC.