Supraventricular tachycardia

What is supraventricular tachycardia?

Any tachycardia that has an origin above the ventricles is technically a supraventricular tachycardia.
This can include
Sinus tachycardia
Atrial fibrillation
Atrial flutter

Atrial tachycardia (not from SA node)
AV junctional tachycardia
AV re-entry tachycardia
AVnodal re-entry tachycardia

Is SVT narrow complex or wide complex?

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)

Can you see p waves on SVT ECG?

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.

Image from wikipedia
SVT full ECG – from wikipedia.

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.

Back to: ACLS Advanced cardiac life support > Heart rhythms