Understanding Overdrive Pacing in Recurrent Torsades

[Catticus11]

I had a patient who was going into Torsades due to congenital prolonged QT. They inserted a pacemaker, at an AV mode and a rate of 120.

Can someone explain what overdrive pacing is, and exactly how it prevents the torsades?

Thank you!

[offlabel]

The rate is programmed to 120? All the time?

[Catticus11]

They tried to taper it down, but at 110 she had a breakout Torsades.

[offlabel]

And this is a permanent implantable pacemaker? No defibrillation component?

[Catticus11]

Originally she had temp wire set at this rate, and then placed a Pacemaker ICD with this rate as well.

[offlabel]

Ok...so she gets defibrillated and goes back into TdP every single time unless she is paced at 120?

[Catticus11]

Yes. Her HR was kept at 120, and if it went any lower she would go into Torsades and she would be shocked by her ICD.

Suspected congenital prolonged QT

[offlabel]

That's crazy...should be a case report.

[nurserobinson281988]

I have had a patient who was in recurrent VT, rate 110-120, so we put an external interrogation/pacing device and set his pacing rate to 130. It was not helpful in this case.

In another case, a patient went into VT and we did the same thing, and it worked. I couldnt tell you why it works, but it does quite a bit.

[offlabel]

I have had a patient who was in recurrent VT, rate 110-120, so we put an external interrogation/pacing device and set his pacing rate to 130. It was not helpful in this case.

In another case, a patient went into VT and we did the same thing, and it worked. I couldnt tell you why it works, but it does quite a bit.

Increasing the rate shortens the QT interval which is the issue in TdP.