February FY20

[sarahrollison]

This months Journal Club is presented by Lisa Lo. She chose an excellent article on the use of leadless pacemakers in anesthesia. Leadless pacemakers (LP) were initially conceptualized in the 1970s. With advanced battery technology, communication capability, and catheter-based delivery systems, leadless pacemakers have became a reality. It is a small self-contained device that is inserted in the right ventricle of the heart. Since we will be having more patients with leadless pacemaker coming in for surgery, Lisa would like to share the perioperative impact of the novel system with you.

Please see the article attached to the February FY20 Journal Club Email. 

Questions to engage in discussion:
1. From your experience, what pacemaker information will you be looking for if your patient with a pacemaker is coming in for surgery?
2. What are the 2 leadless pacemaker systems that are currently available? And how can they be switched to asynchronous mode intraoperatively if needed?

[aileenm4]

hi there
interesting technology, in pediatrics we rarely see pacemakers except in the cardiac patients. But this was helpful to know these devices exist.
Micra transcatheter pace system and the Nanostim leadless cardiac pacemaker
magnets still used for asynchronous mode and in some cardiac surgery sterile magnets on heart needed

[Julienne Chandler]

1. From your experience, what pacemaker information will you be looking for if your patient with a pacemaker is coming in for surgery?

I usually look at the type of pacemaker, last interrogation, percentage of pacemaker dependency, and underlying rhythms/reasons for insertion, and when was it placed. It is sometimes difficult to find this information especially if they are presenting for a case unrelated to cardiology. Now I will know to look out for leadless pacemakers.

2. What are the 2 leadless pacemaker systems that are currently available? And how can they be switched to asynchronous mode intraoperatively if needed?

Reading between the lines here, but it seems like they have a narrower indication and are placed in people with a shorter life expectancy and decreased ADLs/activity. The also have a longer list of contraindications than standard pacemakers with leads. It’s important to remember these are single chamber (RV) pacers.

Nanostim-Abbot (still awaiting full FDA approval):
Has an option to program the device to have the magnet mode turned on or off. If on and magnet detected it will switch to VOO and paces asynchronously at a rate of 100, then after 8 cycles (?) paces asynchronously at 90. When magnet is discontinued, nanostim will revert to previously programmed settings. Nanostim also has an EMI reversion mode that when continuous EMI (>16 Hz) is detected it will revert to VOO asynchronous mode until EMI is no longer detected. Nanostim also has rate modulation mechanism based on blood temperature and if coming off pump or warming/cooling a patient, magnets should be handy to maintain VOO. It was noted that since the LP is in the ventricle and further from skin (especially in obese patients) that there can be unreliability of magnet.

Micra- Medtronic (FDA approved in 2016):
Does not have a magnet mode and will not respond to magnet placement. Asynchronous pacing must be programmed prior to procedure and device should be reprogrammed after procedure.

[Amy Swank]

1. I usually try to ascertain the type of pacemaker that the patient has and when it was last interrogated. Also, how the type of surgery (location) can lead to EMI (more that 6 inches from the heart the less risk).

2. The two leadless pacemakers currently available are Medtronic's Micra and Abbotts Nanostim. Of note is the patient with Micra - as it does not have magnet mode and the asynchronous pacing needs to be programmed in this subset.

(I find the types of pacemakersn(with leads) overwhelming at times - there are so many!)

How interesting to learn about these advances. Besides the limitation of the single chamber being paced, are there any other patient selection limitations for these devices? Eg - higher BMIs, larger necks, difficulty or limited access of the PCA?

Thank you for the interesting article - have many of you participated in these cases? Or seen these patients in other surgeries?

[Jessica Hadley]

1. I typically look for whether the pacemaker is also an AICD, what the mode of function is, and whether the patient is pacemaker dependent. I also consider the type of surgery and likelihood that there may be EMI during the procedure. I would also like to know when the device was last interrogated.

2. The two leadless pacemakers currently available are:
A. Micra transcatheter pacing system (Medtronic):This device needs to be reprogrammed to asynchronous and will not respond to placement of a magnet.
B. Nanostim (Abott): This device can be changed to asynchronous mode by placing magnets over pacemaker site. I felt it was important that the article talked about possibly needing more than one magnet, moving the location, or changing the magnet may be necessary if the device fails to detect the magnet.

[Dahlia Rouchon]

1. The pacemaker information I look for prior to surgery include: pacer type, what is paced, sensed, inhibited, underlying rhythm, if the patient is pacer dependent, what are magnet mode effects (low/high HRs), last device check and documented in the chart, contact phone number for company, and remaining battery life.
2.
a). The 2 devices mentioned in the article are: Micra Transcatheter Pacing System (Medtronic) and Nanostim Leadless by Abbott.
b). To change into asynchronous mode intraoperatively included- Nanostim to be programmed as magnet on/off. Nanostim with magnet would switch to VOO. May have to use more than 1 magnet as it's an intracardiac device. For cardiac surgery the surgical team would need to place the magnet on the heart.
Metronic Micra must be programmed to asynchronous pacing.

[Kels]

1.) I try and look for / get as much information about the pacemaker as possible . I tend to ask the pt about his/her own pacemaker as well . I too like to find out if the pt is in fact pacer dependent. This may be one of the most import pacer facts I like/ need to know. I also want to know about the underlying rhythm , if an AICD is incorporated, last EP visit/interrogation etc

2.) The two leadless pacemakers currently available are Micra transcatheter pacing system (Medtronic) & Nanostim Leadless by Abbott. In order to be switched to asynchronous The Micra transcatheter pacing system (Medtronic)can/should be reprogrammed to asynchronous and a magnet can be used for Nanostim (Abott)

[Jocelyn Datud]

Pre-operatively, I would like to know the type of device the patient has. Whether the patient is pacer-dependent or not, if the device is
functioning properly, and whether electromagnetic interference(EMI) is expected in the planned procedure. And if magnet is used, what management do ween to do afterwards.

Currently, 2 devices are available in the United States: the Micra Transcatheter Pacing System (TPS) and the Nanostim leadless cardiac pacemaker. Magnet response is an important consideration in both conventional pacemakers and LPs. The Nanostim LP has an
option to program the device to have the magnet mode turned on or off. Once the magnet is detected, the device will switch to VOO mode. When the device detects a magnet, the device paces asynchronously at a rate of 100 beats/min for 8 cycles then at 90 beats/min. The device will revert to previously programmed parameters upon discontinuation of the magnet. In contrast, the Medtronic Micra does not have a magnet response and will not respond to magnet placement, and will thus need to be reprogrammed if asynchronous pacing is required.

[Anne McNulty]

I try to obtain all the info that I can regarding the pacer. Eg. Is the pt dependent, is there an AICD, mode of function. Phone interrogation seems to be the most common mode of pacer checks with the patients I have been encountering. Some patients are very knowledgeable , others have no idea. The new leadless pacers will probably show up as a palliative effort in the extremely ill patient. Medtronic has the Micra transcatheter. Nanostim (Abbott)is the competitor. Medtronic Micra transcatheter needs to be reprogrammed to asynchronous mode and does not respond to magnet placement. Abbotts Nanostim will go into asynchronous mode via magnet but requires some moving or another additional magnet. This sounds risky to be doing. Patients with these leadless pacers will need advance planning before they come to the OR.

[Ben Waldbaum]

1. Mode, type of device, chambers involved, battery status, AICD status
2. There are two leadless pacemakers currently, the Micra (requires reprogramming) & the Nanostim (magnet ok)

[Christine Velarde]

When a patient has a pacemaker I would like to know type of PM is there an AICD with a pacemaker and when the PM was placed. I would also like to know battery location last interrogation and if the patient is pacemaker dependent. I also would like to know maker and number of leads.

2. The the type of leadless pacemakers are the Micra and the Nanostim. The Micra (Medtronic) does not respond to magnet placement. I needs to be reprogrammed to asynchronous pacing mode ir required for surgery. The Nanostim does have a magnet mode which if it detects a magnet will switch to VOO . It will pace asynchronously at a rate of 100 beats per min for 8 cycles then 90. beats per min

[clawry]

Questions to engage in discussion:

1. From your experience, what pacemaker information will you be looking for if your patient with a pacemaker is coming in for surgery?

2. What are the 2 leadless pacemaker systems that are currently available? And how can they be switched to asynchronous mode intraoperatively if needed?

1. I will be looking for type of pacemaker, mode, is it a pacer/ICD, when it was last interrogated, can you use a magnet to change to asynchronous mode/disable ICD, is the patient dependent on pacemaker, what type of EMI and how close to the pacemaker will EMI be? Review chart to read the pre-op cardiology note for recommendations regarding the pacemaker and relay to surgical team during time out or speak to surgeon and anesthesiologist pre-op if there are any major concerns regarding pacemaker.

2. The 2 leadless pacemaker systems that are availabe are the Nanostim (St. Jude) and Micra (Medtronic).  The Micra has to be reprogrammed pre-op to asynchronous mode. Magnets will not work. The Nanostim has an option to have magnet mode turned on or off. Magnet response can be variable-you may have to use more than 1 magnet or move the magnet around to get a response. For cardiac surgery the magnets must be placed on the heart in a sterile fashion.

I was lucky enough to participate in the anesthesia care for the placement of a Micra leadless pacemaker a few weeks ago. The patient tolerate the procedure well under MAC. I used versed, fentanyl, and a propofol infusion. 

[rboynton]

1. Information that I look for with a pt coming in for surgery with an exsisting Pacer: Most importantly, I think, last time the pacer was interrogated so that you know it is properly functioning. What is the underlying rhythm, are they pacer dependent, do they have an AICD, and make sure you know where the magnet is and have it available.
2 The 2 leadless pacemaker systems that are available are the Micra Transcather Pacer System (TPS) and the Nanostim leadless cardiac pacer. The Nanostim has the option to program the device the have the magnet mode on or off. You can use the Magnet with the Nanostim. When the magnet is detected, the device changes to VOO mode. The Micra does not respond to the magnet and will need to be reprogrammed before surgery.

This was a great article. Thanks

[emedina1]

If a patient is coming for surgery, I would like to know when the pacemaker was interrogated. I would be interested if the pacemaker is leadless and what kind. At this point only two systems are available.
the two types are Micra Transcatheter Pacing System and the Nanostim Leadless.
The Nanostim has the capability to be programmed for magnet on or off .

[khall]

1. From your experience, what pacemaker information will you be looking for if your patient with a pacemaker is coming in for surgery? I try to find out as much information as possible: mode, last interrogation, underlying rhythm, whether or not they are dependent.

2. What are the 2 leadless pacemaker systems that are currently available? And how can they be switched to asynchronous mode intraoperatively if needed? Nanostim that is responsive to magnet and Micra that must be reprogrammed.