This atrial arrhythmia occurs when the natural cardiac<unk>  site shifts between the SA node, the atria, and/or the AV node. This shifting of the<unk>  from the SA node to adjacent tissues is manifested electrocardiographically by transient changes in the size shape and direction of the P waves.
A<unk><unk>  is usually caused by varying vagal tone. With increased vagal tone the SA node slows,allowing a<unk>  in the atria or AV Nodal area,which may become slightly faster briefly. After vagal tone decreases the SA node becomes the<unk>  again.Note that if the heart rate increases to above 100bpm, it is called multifocal atrial tachycardia. Possible causes are hypoxia, COPD and medication such as digoxin.
Wandering atrial pacemaker
Fascicular VT
Sinoatrial nodal reentry tachycardia
Ventricular escape beat
Mahaim type preexcitation
AV reentrant tachycardia
Ectopic atrial rhythm
Paroxysmal AV block