wandering pacemaker

Wandering pacemaker is usually caused by varying vagal tone.

Ventricular conduction is normal with wandering pacemaker, and thus the QRS complex is normal.

In cardiology, a wandering pacemaker is an atrial arrhythmia that occurs when the natural cardiac pacemaker site shifts between the sinoatrial node (SA node), the atria, and/or the atrioventricular node (AV node).