These are of following types:
1. Paroxysmal atrial tachycardia.
2. Re-entrant atrial
tachycardia which includes
fibrillation and flutter.
3. Atrioventricular nodal re-entrant tachycardia (AVNRT)
utilising concealed bypass tract. This includes WPW
4. Multifocal or chaotic atrial tachycardia.
5. AV junctional tachycardia which may be paroxysmal and non-paraxysmal.
WANDERING PACEMAKER IN THE SINUS NODE
Here there is passive transfer of the predominant pacemaker focus from the SA-node to another latent pacemaker having
the next highest automaticity in the atrial musculature or in the AV junctional tissue. In the ECG there may be a cyclical
increase in the R-R interval, gradually shortening PR interval and change in P-wave configuration. Persistent increased vagal tone may be responsible for it.