Boston Scientific Latitude device interrogation

It's Alerts recorded in the device

by crustyg - 2022-03-16 15:20:33

And, from personal experience, not even Events (not the same, as I've learnt).

Each device can be configured to record certain types of Events and have Alerts associated with them (e.g. VTachy EGM where rate >180BPM): Latitude makes a brief connection to your device every night and if there's nothing new in the Alerts log, disconnects.  If there's something then your device passes the info, but I'm fairly sure it's high-level stuff like non-sustained ATachy for <x> seconds.  The radio connection between PM and latitude takes quite a bit from the battery, and passing over 15s of heart trace would consume a lot of battery.  BostonSci quote their device battery life to include daily Latitude communication (because it's so brief).

However, I had to attend in-person twice in 6days last Dec: my report from 2nd in-person session showed a whole year less battery life, as we spent a bit of time with me connected to the Programmer console while we worked out how to reset a particular setting.

Accolade can store detailed EGM (not actually ECG, but it's the same concept) for a short time, or less detailed info for more episodes - your device will be set to one or the other.  Different devices have differing EGM storage capabilities.  But you aren't walking around with a full-spec ECG machine in your chest.  I've read, and re-read the BradyPacer ref manual (not the CRT-x manual) and it's not clear if the patient-initiated data transfer can be set to capture an EGM.  For me, a patient initiated transfer has to be set up in advance, otherwise Latitude reports a fault (bright orange glow), *but* your EP-techs can set the receiving end up to always be expecting a transmission.  The devices do seem to have a rolling memory, as the PDF talks about 10s of EGM before Snapshot and 2s after, which would make sense.

What is stored

by Gemita - 2022-03-16 16:21:19

Ian,

I will try to answer some of your questions, although I have a Medtronic pacemaker.  I see you have already received good advice from crustyg.

The downloaded 6th monthly report is unlikely to be a beat by beat account of what your heart is doing every minute of each day.  There wouldn’t be sufficient storage space in the pacemaker to record this level of detail. 

Instead it will be a report of any significant events, like high heart rates, irregular heart rhythms, duration and speed of any arrhythmias, % time you are being paced in the atrium, % time in the ventricle, % time you spend in an arrhythmia like AF, Atrial Flutter or Ventricular Tachycardia (called arrhythmia burden), battery, lead status etc.  In other words, they are primarily looking to record significant information/events.  A fast, significant arrhythmia should be stored and able to be viewed on EGMs (stored electrograms) but only if it meets the parameters set up by your doctors for its storage. 

When you feel unusual symptoms and initiate a transmission they will usually be able to see what is going on from the downloads for any given period although if you or they are in any way concerned, you will be asked to attend clinic.  I don’t think you should worry about the period before or after transmission being lost, just focus on sending the transmission as soon as you start to feel any symptoms and they will usually be able to tell you what rhythm disturbances you are getting and their significance. 

You need to ask your clinic what has been set up, since your doctors may not be interested in benign stuff like ectopics which can be a frequent source of distress for so many of us.  My pacemaker is rejecting any ectopics, recording instead arrhythmias like Multi Focal Atrial Tachycardia and Ventricular Tachycardia episodes, where these are seen.  

Your doctors will set up a report based on the parameters they have set to record important information.  It is quite specific.  For example, they may only be interested in an arrhythmia when it reaches a certain speed (say over 180 bpm) and for a certain duration, with anything less being rejected.  Depends what your doctors have set up.  Does that help a little more?

More or less as I thought and some concerns

by IanMK13 - 2022-03-24 14:58:05

Thanks, crustyg and Gemita.  I had already assumed that the routine downloads must be summary reports of some kind and thought from my discussions with the pacing clinic that a more detailed report must be available when the Latitude button is activated. Both rre- and post-event data would be ideal, of course, but I wondered about the recording duration of each.  I should have mentioned that my device is a Visionist X4.

My device was implanted by a leading EP in London. Whereas I am confident in the initial configuration of the device, it is now managed by a local pacing clinic who admit that they have not seen many of these devices. Not wishing to be critical, I am a little concerned at their level of expertise with my particular device and it may not now be being used to best effect..  The configuration may or may not have been changed since it was implanted and no EP  or cardiologist is overseeing my care, to my knowledge.