Overdrive Pacing
OVERVIEW
- Overdrive pacing = pacing the heart at a higher rate than the native heart rate
- VT or VF can result -> always have DC cardioversion available
INDICATIONS
- failure of drug therapy
- recurrent arrhythmia
- contraindication to cardioversion (digoxin toxicity)
- aid to differentiate VT from SVT
RHYTHMS THAT CAN BE CONTROLLED
- AV junctional tachycardia
- paroxysmal re-entrant SVT
- atrial flutter (rate 320-340)
- SVT with rapid ventricular response that fails to revert
- VT (may precipitate VF)
RHYTHMS THAT CAN’T BE CONTROLLED
- AF
- VF
- sinus tachycardia
OVERDRIVE PACING VS CARDIOVERSION
- may assist with rhythm diagnosis
- can use in digoxin toxicity
- doesn’t require GA
- avoids complications of DC shock (myocardial depression)
- pacing available post electrical version (in case of bradycardia or asystole)
OVERDRIVE PACING VS DRUGS
- may aid in rhythm diagnosis
- avoid drug induced cardiac depression and other side effects
- can be used when drug therapy fails
- termination of the tachycardia with pacing often immediate
- standby pacing immediately available
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC
Hi! This might be playing with semantics, but I did not think that AV junctional tachycardia would usually be categorized as a rhythm that can be “overdrive paced”? As a supportive measure, we will indeed atrially pace children with post-operatve JET at a faster rate than the junctional rhythm until it self-resolves (to regain AV synchrony and ensure better cardiac output). I had previously understood that “overdrive pacing” is usually a term reserved for pacing at a faster rate with the goal of “breaking” the arrhythmia by disrupting the re-entrant circuit or over-riding the ectopic pacemaker, and it is performed over a few seconds. Let me know if I’ve misunderstood it – I was involved in teaching pacing to australian exam-takers and I wanted to clarify the term. Thank you very much.
Why can’t atrial fibrillation be overdrive paced?
Hi M,
I believe (and I’ve just consulted with a cardiologist as well as some of the literature) that it’s because it just isn’t effective. There were some early noughties (early ’00s to early ’10s) trials that looked at long-term prevention in pAF (and treatment) and overdrive atrial pacing and there wasn’t a benefit (unless you were a pacemaker company, because the batteries required replacing more frequently). Best evidence is with atrial flutter, SVT (can convert to AF sometimes) and VT (with ventricular overdrive pacing — although a high risk of converting to VF, and VF can’t be overdrive paced!).
There was some earlier evidence that bi- and/or multi-site atrial pacing may be more effective at overdrive atrial pacing, however this hasn’t really come to fruition, nor is it currently practised (to my knowledge) — the atria are fibrillating and are difficult to re-synchronise!
Hope this helps,
James