Any tachycardia that has an origin above the ventricles is technically a supraventricular tachycardia.
This can include
Atrial tachycardia (not from SA node)
AV junctional tachycardia
AV re-entry tachycardia
AVnodal re-entry tachycardia
As we have discussed earlier, if an impulse originates above ventricles it should be narrow complex. But the exceptions are SVT with a block and Antidrome (in reverse direction) AV re-entry tachycardia (via bundle of Kent) can have wide QRS complex (>0.12 seconds)
Due to rapid contractions of ventricles, p waves may be hidden in the QRS complexes or preceding T waves or can be seen with a small amplitude. In some cases as shown in the strip underneath, you might see p waves in some waves.
The heart rate typically varies between 150-250 depending on what type of SVT is that.
And Adenosine may not work in all of the SVTs. More on that in subsequent lessons.