Overdrive Pacing

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tklingbeil

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I was on shift tonight with my partner, he is an older medic about 26 years in, he told me about overdrive pacing for SVT. Came about due to witnessing a SVT come into the ER while we were waiting for a bed (they did not use this technique for those curious). He said they used to teach it in ACLS but have gone away from it. Has anyone on here heard of it? If so have you seen it done? Did it go well?
 
I have heard of it. But never seen it done or actually had a provider suggest it as a treatment.
 
Wasn't it also a tactic for refractory VT?
 
Yea I believe it was. Breaking the cycle by taking control and bringing it to where you want it to be is the thought process. Ive found some information on it on web but I wanted to see if anyone has ever seen it first hand or if it was a protocol that someone might have had back in the day and actually have done it. Be kinda cool if anyone has a first hand account. My partner had seen it one time in an ER and said that it worked but then they could not back it down without the guy crashing.
 
My protocol has that Chaz. Shocking someone with two LP 15s. Ive yet to see it live but I can not wait until I do.
 
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Interestingly, some implanted ICD's can do overdrive pacing as well.
 
I have never done it with pads. However, in patients with temporary cardiac pacing wires we attempt it relatively frequently. Typically I will use it in patients with a-fib RVR before I attempt drugs or cardioversion. If I can capture with the atrial lead (which tend to be unreliable in the first place), I will pace them about 10 beats faster than the native rate for about 5 minutes and while we optimize the pH and the electrolytes. Then, slowly dial back the rate. I would give it about a 30% success rate, just estimating.
 
Common feature in implanted aicd/pacers to manage vt.

While we can do it with epicardial wires and can do that for svt, I've only done it with transvenous wires to manage VT storm in a complete heart block patient awaiting full amio loading to allow safe tvp wire removal prior to definitive ep treatment. Maybe it was somewhat effective...

I've never seen transcutaneous overdrive pacing.
 
I was taught how to do it, but pharmacological interventions generally work with the experiences I've had.
 
I've also been taught how, but I've never seen overdrive TCP done and my experience is that pharm interventions worked relatively well. I also used to play with E-stim machines and it's quite interesting how the body responds when you change the pulse width, voltage, current... I would imagine that if you could change some of the parameters a bit (besides rate and mA) you might see some instances where you get greater capture when overdrive pacing.
 
Just remember that the maximum pacing rate of a LIFEPAK is 180 PPM. I worry about overdrive pacing simply because 90+% of the time when I review a transcutaneous pacing case it turns out to be false capture. I have not tried it but I would consider it for torsades de pointes refractory to magnesium sulfate. As a side note if you attempt TCP on a patient with an ICD I would strongly encourage you to apply a ring magnet first.
 
TomB said:
Just remember that the maximum pacing rate of a LIFEPAK is 180 PPM. I worry about overdrive pacing simply because 90+% of the time when I review a transcutaneous pacing case it turns out to be false capture. I have not tried it but I would consider it for torsades de pointes refractory to magnesium sulfate. As a side note if you attempt TCP on a patient with an ICD I would strongly encourage you to apply a ring magnet first.
Click to expand...
I was going to bring up the point that I'm not sure most monitor/defibrillators are capable of pacing at a rate where overdrive pacing works....
 
TomB said:
Just remember that the maximum pacing rate of a LIFEPAK is 180 PPM. I worry about overdrive pacing simply because 90+% of the time when I review a transcutaneous pacing case it turns out to be false capture. I have not tried it but I would consider it for torsades de pointes refractory to magnesium sulfate. As a side note if you attempt TCP on a patient with an ICD I would strongly encourage you to apply a ring magnet first.
Click to expand...

I know you commonly report on false capture cases. When Medics are taught pacing, they are often taught that you turn up the amps until you feel pulses, improve mental status and symptoms. Are you seeing a lot of false capture cases because providers are afraid to turn up the amps?
 
Insufficient milliamperes is definitely the number one cause.

The skeletal muscle twitching can be impressive. Combine that with a pseudo-QRS complex that gets larger as you dial up the current and it's easy to see how it happens. What paramedics are taught carries no weight with me because most people doing the teaching have never achieved capture (and many have never even attempted the skill in real life).

Read more about the problem of false capture here:
http://www.ems12lead.com/2008/11/15/transcutaneous-pacing-tcp-the-problem-of-false-capture/

A rare case of true electrical and mechanical capture here:
http://www.ems12lead.com/2011/02/01/transcutaneous-pacing-tcp-for-asystole/

A case where beside echo was used to confirm capture here:
http://www.ems12lead.com/2015/11/30/transcutaneous-pacing-put-it-up-to-eleven/

Vince D.'s 2-part series.
Part 1: http://www.ems12lead.com/2015/03/19/tcp-success-part-1/
Part 2: http://www.ems12lead.com/2015/03/20/tcp-success-part-2/

Chris W.'s review of TCP:
http://www.ems12lead.com/2014/05/02/revisiting-transcutaneous-pacing/

Tom
 
Now that I think about it, I have seen one case of overdrive pacing attempted. It was a few months ago when we were well into a arrest in the ED and cardio came down and did it for refractory VFib I believe. We never got capture and the patient never got ROSC.
 
ETCO2 rise would be a good indicator of mechanical capture.
 
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