micra leadless pacemakers

[anbuitachi]

Seeing a lot more frequency in patients showing up with leadless micra pacemakers. Our cardiologists dont have the machine to interrogate leadless pacemakers. They dont respond to magnet, and theres nothing i can really do to it anyway. In that case, for patients that are dependent and are showing up for surgery that doesnt require electrocautery anywhere near the site, but in emergencies may turn into something that do (eg cerebral angio/embolization), what are you guys doing for these cases? I know there is a HIGHHHHH chance everything will be just fine, but we dont have any policy on this

these patients are showing up uninterrogated for somewhat elective cases

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[BLADEMDA]

WOW

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7879905/pdf/ACA-23-493.pdf

Anesthetic Consideration for Patients with Micra Leadless Pacemaker - PMC

MICRA, miniaturized leadless single chamber pacemaker, is inserted directly into the right ventricular myocardium via transcatheter approach. We present a case of a 66-year-old patient with a Micra pacemaker scheduled for kidney-pancreas transplant. ...

www.ncbi.nlm.nih.gov

See Table 1:

External Pacemaker and Defi pads
Bipolar if possible
Keep Bovie pad 6 inches from device
Inform Surgeon the patient may arrest so keep the bovie bursts short and sweet


The harmonic scalpel is a surgical instrument that (unlike electrosurgery) uses ultrasonic vibrations to cut and cauterize tissue.

 

[vector2]

 

[anbuitachi]

thanks everyone. thats actually very helpful! even a phone #! haha

I think the biggest difference is lack of ability to use magnet to do anything. Previously if they are super far away or are not planning on using electrocautery, i just have a magnet available for pacemakers. However here, because of how much effort it would take to reprogram to VOO if theres no CIED team readily available, the question then becomes for which patients should be reprogrammed (obviously if very close, get reprogrammed, but what if they are working on the FEET? or no electrocautery expected)? Would you leave the dependents as is, and be prepared for emergency management in ways blade mentioned or would you want every dependent patient to be reprogrammed?

 

[BLADEMDA]

This resection was undertaken carefully with the harmonic scalpel.

An Uncommon Intraoperative Implantable Cardiac Device Complication and Subsequent Troubleshooting - PMC

www.ncbi.nlm.nih.gov

 

[BLADEMDA]

thanks everyone. thats actually very helpful! even a phone #! haha

That's not helpful after hours, weekends and at night when the patient is a trauma or true emergency. Good Luck with the 1-800 number when you really need help.

Those numbers are for elective cases where you can wait for a Medtronic rep or cancel the case. You need a plan for 24/7 365 days per year. Yes, I have called the "help line" before and typically get the Medtronic Rep to come in (reluctantly most of the time).

The most valuable piece of information that you need to know is the following:

"Is this patient pacemaker dependent and what is his/her intrinsic rate?"

I can personally testify that you don't want to find out in the O.R. (like I did) that the patient doesn't have an intrinsic rate!

 

[BLADEMDA]

EMI from electrocautery can result in pulse generator inhibition or component failure, atrial or ventricular tachycardia and fibrillation, loss of/change in output, reprogramming of rate or mode of function, runaway pacing and electrical burns at the myocardial-electrode interface.[2]

Studies have shown that Monopolar devices cause far more EMI then bipolar.[2,3] In monopolar electrocautery, current must dissipate through the body and return to generator via the return electrode called electrodispersive pad (falsely known as grounding pad).[1] Bipolar coagulation cautery causes minimal problems as the current flow is localized between the two poles of the instrument. However, bipolar devices are used less commonly than monopolar devices since it only offers coagulation, not dissection.[4,5]

An alternative to electrocautery is the ultrasound-based devices. Ultracision® (Ethicon Endo-Surgery Inc., Cincinnati, OH, USA) represents a unique surgical device (harmonic scalpel) capable of performing both cutting and coagulation at different intensities without the use of electric energy.[6

 

[vector2]

It's not rocket science. If magnets don't work and the case is an emergency and there's no rep coming then there's only so many things one can do.

Zoll pads on
Maybe a-line
Grounding pad directing current away from the micra
Request no bovie
Request bipolar or harmonic
If must use monopolar, use intermittently while watching rhythm/a-line

 

[anbuitachi]

That's not helpful after hours, weekends and at night when the patient is a trauma or true emergency. Good Luck with the 1-800 number when you really need help.

Those numbers are for elective cases where you can wait for a Medtronic rep or cancel the case. You need a plan for 24/7 365 days per year. Yes, I have called the "help line" before and typically get the Medtronic Rep to come in (reluctantly most of the time).

The most valuable piece of information that you need to know is the following:

"Is this patient pacemaker dependent and what is his/her intrinsic rate?"

I can personally testify that you don't want to find out in the O.R. (like I did) that the patient doesn't have an intrinsic rate!

Yes for sure, that's my main issue, they are not readily available. Therefore i am uncertain if all dependent patients should be reprogrammed in case of rare events/emergencies (though there are risks to that too..) and have that programmed back post op, or still only ones working close by should be reprogrammed.

 

[BLADEMDA]

Yes for sure, that's my main issue, they are not readily available. Therefore i am uncertain if all dependent patients should be reprogrammed in case of rare events/emergencies (though there are risks to that too..) or still only ones working close by should be reprogrammed.

My case was an umbilical hernia in a patient with an AICD. The patient was paced at a rate of around 80. The older AICDs were much more sensitive to electrocautery and the surgeon refused to use a bipolar. The patient would have NO RATE when the surgeon used the bovie. I got through the case and the patient went home. Lesson learned. Yes, I even tried taking off the magnet.

Anyway, I hope to never encounter that scenario again and if you must do a case with a MICRA pacemaker just be prepared for the worst. Typically, the newer pacemakers are very resistant to bovie interference but I have never encountered a MICRA pacemaker yet. So, I am not as comfortable with "just doing the case" as usual.

 

[BLADEMDA]

Intraoperative Monitoring:

Consider manually monitor the patient’s rhythm (take pulse);
Consider monitoring the patient by some other means such as ear or finger pulse oximetry, Doppler pulse detection, or arterial pressure display. Postoperative: Consider postoperative interrogation if a) monopolar electrocautery was used, b) patient is hemodynamically unstable, and c) after cardiothoracic surgery, radiofrequency ablation or external cardioversion

 

[anbuitachi]

It's not rocket science. If you can't put a magnet on and the case is an emergency and there's no rep coming then there's only so many things one can do.

Pads on
Maybe a-line
Ground pad directing current away from the micra
Request no bovie
Request bipolar or harmonic
If must use monopolar, use intermittently while watching rhythm/a-line

right, i meant if the case isnt an emergency.

If patient comes from home and is dependent, is your decision to reprogram to VOO the same as in non leadless pacemakers?

If dependent and working near site then -> reprogram
If dependent and working far from site --> reprogram? or hope for the best and be ready for emergencies? (if non micra i would just have magnet available, but not on the patient)
If no electrocautery is expected --> leave it as is?

Imagine patient comes in from home for cerebral embolization of aneurysm. Patient has Micra and is dependent for CHB. No electrocautery is expected. but electrocautery may be used in emergencies (hemorrhage turning into craniotomy; RP bleed, etc). Would you ask for this patient to be reprogrammed, or not and just be ready for emergencies? What if case was a bunion on the feet? Just be cautious without reprogramming?

 

[BLADEMDA]

Okay,

So here is the LIKELY outcome, 99%, if you just do nothing about the MICRA pacemaker and just do the case:

Although this is a small case series, it is encouraging that there is no evidence of EMI in neck, abdominal, and lower extremity procedures. There is a possibility that very short episodes of oversensing were not stored, but this would likely be of no clinical significance. We were only able to evaluate heart rate histograms, as there are no stored episode details or logs in Micra leadless pacemakers. Although Medtronic’s recommendation for minimizing risk of surgical EMI is consistent with transvenous devices, the clinician workflow and true risk of EMI in leadless pacemakers still needs to be determined.

Evaluation of surgical electromagnetic interference in leadless pacemakers - PMC

www.ncbi.nlm.nih.gov

 

[BLADEMDA]

I would like to add that monopolar cautery within 6 inches of the device could be an issue. I have personally seen this with newer pacemakers where electrocautery was used within 6 inches of a brand new, state of the art pacemaker. This was just a pacemaker and not an AICD. No magnet was placed.
The case was cancelled and the patient sent home because there was NO INTRINSIC RATE when the bovie was applied.

So, if you are doing any kind of surgery where monopolar cautery is used within 6 inches of the right ventricular wall I would be prepared for the worst case scenario.

 

[Guillemot]

This podcast and accompanying article goes over some stuff of interest ‎Anesthesia and Critical Care Reviews and Commentary (ACCRAC) Podcast: Episode 198: Non-Transvenous Cardiovascular Implantable Electronic Device Technology on Apple Podcasts

 

[Blockit]

Blade, thank you for all of your commentary on this relatively new animal that we are seeing in the operating rooms. I know that somebody commented on this in a prior thread, but it is worth re-stating that private practice cardiologists are basically learning how to do this ON patients in real time, similar to how Mr. Musk beta tests his self driving system on the drivers of his cars. A few weeks ago we had a cardiologist perforate the right ventricle during placement of one of these leadless pacemakers. Thankfully, he left the device in place while the patient was emergently rushed to the open heart room. Median sternotomy was performed and the right ventricle was oversewn after the removal of the device. I shudder to think about what would have happened to the patient had the cardiologist panicked and removed the device while still in the Cath Lab.

If you are involved in the placement of one of these devices, for the forseeable future it should not be considered a “routine” pacemaker placement.

 

[nimbus]

Blade, thank you for all of your commentary on this relatively new animal that we are seeing in the operating rooms. I know that somebody commented on this in a prior thread, but it is worth re-stating that private practice cardiologists are basically learning how to do this ON patients in real time, similar to how Mr. Musk beta tests his self driving system on the drivers of his cars. A few weeks ago we had a cardiologist perforate the right ventricle during placement of one of these leadless pacemakers. Thankfully, he left the device in place while the patient was emergently rushed to the open heart room. Median sternotomy was performed and the right ventricle was oversewn after the removal of the device. I shudder to think about what would have happened to the patient had the cardiologist panicked and removed the device while still in the Cath Lab.

If you are involved in the placement of one of these devices, for the forseeable future it should not be considered a “routine” pacemaker placement.

Leadless PM

https://www.heartrhythmjournal.com/action/showPdf?pii=S1547-5271%2821%2900207-1 Mostly failure to rescue after perforation/effusion/tamponade. It appears micra can leave tears up to 2.5cm in the RV wall. I’ll take the old fashioned one, at least for now. Thanks.

forums.studentdoctor.net

 

[vector2]

right, i meant if the case isnt an emergency.

If patient comes from home and is dependent, is your decision to reprogram to VOO the same as in non leadless pacemakers?

If dependent and working near site then -> reprogram
If dependent and working far from site --> reprogram? or hope for the best and be ready for emergencies? (if non micra i would just have magnet available, but not on the patient)
If no electrocautery is expected --> leave it as is?

Imagine patient comes in from home for cerebral embolization of aneurysm. Patient has Micra and is dependent for CHB. No electrocautery is expected. but electrocautery may be used in emergencies (hemorrhage turning into craniotomy; RP bleed, etc). Would you ask for this patient to be reprogrammed, or not and just be ready for emergencies? What if case was a bunion on the feet? Just be cautious without reprogramming?

For your endovascular neuro case and a bunion case I would not reprogram. I am pretty conservative when it comes to reprogramming PPMs unless the pt is PPM dependent and they're bovie'ing on the torso.

This is doubly so when talking about someone with a newish PPM because new ones are much better at filtering EMI.

 

[BLADEMDA]

I NEVER reprogram a pacemaker less than 6-7 years old unless the surgery is within 6 inches of the device. I do routinely get the devices checked postop if the surgery was close to the device or I see any rhythm issues intraop or postop.

The new pacemakers are very resistant to monopolar cautery and I simply proceed as usual without a magnet on the device. I do keep a magnet in the room. But, if the surgery/bovie is going to be close then interference becomes a real concern and I won't do any elective case without re-programming.

As for MICRA, I will use that same strategy on patients but with a bit more caution due to my lack of experience with MICRA pacemakers.

Please do not confuse my this post about Pacemakers with AICDs. AICDs are different animals all together.

 

[BLADEMDA]

How to initiate asynchronous pacing in a Medtronic pacemaker with a Medtronic Model 9466 patient magnet All Medtronic pacemakers, including all MR Conditional and MR Unsafe models, enter “magnet operation” with the application of a magnet. During magnet operation, a pacemaker paces in an asynchronous mode at either 85 min–1 or 65 min–1, depending upon whether the pacemaker battery voltage is above or below its elective replacement threshold. Sensing is suspended during asynchronous pacing to prevent pacing inhibition by EMI. Note: As an alternative, you can program asynchronous pacing during a telemetry session with a Medtronic programmer or with a Medtronic device manager. If telemetry is established with an implanted pacemaker, a Medtronic Model 9466 patient magnet will not initiate magnet operation.

 

[Iso4ane]

And it was kinda brushed, but just because somebody is 100% paced does not necessarily mean they are pacemaker dependent. The could just have a slightly slower but hemodynamically stable rate/rhythm. However, on the other hand they could have no intrinsic rate, and don’t what to figure out the hard way.

 

[Hork Bajir]

If anyone really wants to become an expert on this stuff, I recommend this website:

PEPT

www.pept.org

Watch all of the educational videos. It takes about 20 hours to watch it all. At the end, you will be amazed how much you didn’t know before. It is intended for people who want to learn basic device interrogation and programming, but I think it’s all relevant for anyone who takes care of patients with these devices

 

[abolt18]

If anyone really wants to become an expert on this stuff, I recommend this website:

PEPT

www.pept.org

Watch all of the educational videos. It takes about 20 hours to watch it all. At the end, you will be amazed how much you didn’t know before. It is intended for people who want to learn basic device interrogation and programming, but I think it’s all relevant for anyone who takes care of patients with these devices

One video in. Very pleased with it. Looking forward to learning WAY more than I ever intended about pacemakers.