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). This shifting of the pacemaker from the SA node to adjacent tissues is identifiable on ECG Lead II by morphological changes in the P-wave; sinus beats have smooth upright P waves, while atrial beats have flattened, notched, or diphasic P-waves.
Ventricular conduction is normal with wandering pacemaker, and thus the QRS complex is normal.
Wandering pacemaker is usually caused by varying vagal tone. With increased vagal tone the SA Node slows, allowing a pacemaker in the atria or AV Nodal area, which may briefly become slightly faster. After vagal tone decreases, the SA Node assumes its natural pace.
It is often seen in the very young, very old, in athletes and rarely causes symptoms or requires treatment.
Famous quotes containing the word wandering:
“A wandering Aramean was my ancestor...”
—Bible: Hebrew, Deuteronomy 26:5.