Charge 2 Heartbeat after death

[Nanneke]

Yesterday somebody died wearing her Charge 2.  To determine the exact time of death we thought we could use the FitBit. Much to our surprise the FitBit still showed a heartbeat. Even 45 minutes after being declared dead there was still a heartbeat shown on the watch and the I-phone!! How is this possible?

Moderator edit: subject for clarity

[SunsetRunner]

I don't think anyone has an answer for this.

[bunnymad]

I don’t have an answer for you but this exact thing has happened to me too, which is how I stumbled upon your post. My husband died between 19:15 and 19:30, when he was certified dead. The FitBit shows a heart rate for a further four plus hours. I was really hoping for an exact time of death from his FitBit reading, I can’t understand how the FitBit didn’t realise there was no pulse. 

[Matta2010]

Same thing happened to my dad. Almost four hours after death it still showed a pulse. However when the Fitbit was removed it stopped.

[JimmyLewis]

My father in law (81 yrs old) died at 10:52 & we can see his heart rate go up and down, and up again then stop at that time.  We arrived 5 hours later to view the body and you can see that while my wife is hugging her dad his pulse starts again for approx 20 mins!!! First at a high rate again, then steadying to normal, then stopping, then a weird single line and then it was removed from his wrist.   Weird eh? Any other similar stories? 

[Nanneke]

I recently bought a new Fitbit. During the set-up I had to indicate what the lowest heartrate was that was to be measured. Maybe this had something to do with the strange measurements after death. After the first set-up I have not been able to find the place to change this setting.

[JimmyLewis]

I don't think that explains it Nanneke. J 

[Samantha_cass]

Seems like an odd question, but my mother in law recently passed and we checked her fitbit which registered several large spikes for several hours after her death, when she had not been moved (waiting to be taken to the funeral home). I assumed when the heart stopped, the fitbit would stop? We also noticed this happening in her short bursts for several days afterwards, perhaps how they stored the fitbit until we picked it up. Has this happened to anyone? If this is picking up a heartrate when there is none, why? 

[HenleyTheCat]

Still not seeing answers. Had the same thing with my mom at 6:35 but well after 7 it was still showing a heartbeat. I was beside myself with that was it wasn’t going on. I’m not sure if we should have been trying to do something but she had a DNR so I just sat horrified and the nurse took her watch off. 

[Sreinhard]

The same thing happened with my husband who passed away last March 2021.  He had his fitbit on passed away at 3:05 pm.  The hospice nurse came over and could not hear a heartbeat.  The family was all around and we watched him take his last breath and then no more.  It was several hours before the funeral home came to get him from our house.  Right before they took him, I took off his fitbit Charge 3.  A week or so later, when I was checking my activity, I also checked his.  I was shocked that his heart was still beating several hours after he was declared dead.  I had a terrible feeling that maybe when they made a mistake!  It still haunts me to this day.

[Bloggins]

First reported February 2019. FitBit's response? Nada, Nothing. This is the same response that they give for 95% of the problems and issues brought up by users. FitBit excels at ignoring it's customers, their questions and what they wear on their wrists. I've had three, all partially replaced under warranty. I say partially, because all these guys do is send you a voucher for 25% off a new purchase. We've been asking for the Charge series to use Canadian banks for their app. Over 10 years and thousands of requests, they still ignore the issue and won't provide an explanation.

[Skymomma]

My daughter died by suicide. I noticed her heart rate was 190 and then it stopped. I saw more activity but assumed it was the tech taking the device of her arm. A few hours later the device shot back up and had a short burst of active activity- I assumed it was when her dad went to identify her and pick up the device from hospital. Now, I am not sure. He doesn’t remember. I screen shot her last breath on the Fitbit. It’s a strange visual. Shattered.

[relietz]

This is pure speculation, but I'm going to posit a possible theory:

We typically observe heart rates by feel (pulse on the wrist or neck) or sound (listening for a pulse). If a device like a fitbit instead uses electrical pulses to monitor heart rate, and it is set to be very sensitive (threshold very low), it may pick up residual electrical pulses which may remain in/ continue between the nerves in the body long after the pulses stop being strong enough to actually contract the heart or power the neurons. (So, basically after brain death and after heart failure, but before all electrical activity has left the body.)

This wouldn't necessarily indicate life-sustaining activity, brain activity, or potential for resuscitation, but simply that the living organisms which power our body (cells and the activity between them) do not instantly cease to function when the body as a whole stops. When the body is living, these impulses would cause things to function, the heart to beat, arteries to contract, sensations to be felt, etc. But when the body as a whole has stopped, these electrical signals can no longer trigger anything to happen, and eventually they would fade until they are not happening any more. 

Perhaps that theory could, not only explain why an electrically-based device will continue to pick up the electrical impulses we read as a heart rate after the heart has stopped, but also offer some closure to those who have experienced it and might be left wondering.

(As an added thought, medical devices are likely set to only read those impulses above a certain threshold, which prevents them from continuing to give back readings like these after the body stops. That would also explain why a fitbit might read it where a medical device does not. Since fitbit is designed to support those who are actively living, and not specifically meant as a time of death device, it might make sense that it would be set to be very sensitive in order to give the most accurate readings.)

[thatotherguy123]

Interesting theory, but that's not how the FitBit works. Rather than detecting electrical impulses, it shines light from a light-emitting diode into the skin. With this light, it can "see" your capillaries. When your heart beats, it sends a pulse of blood through your arteries, which also travels through your veins and capillaries. Thanks to the light on the back of the FitBit, it can see the change in the diameter of your capillaries as that pulse pushes downstream. If it sees 90 such throbbings per minute, then it reads a heart rate of 90 bpm.

So that leaves me wondering... with that pulse gone, does the FitBit start grasping at straws and interpreting other movements as heart rate? After death, the body still moves. Muscles, including sphincters, relax. Bacteria remains alive in the gut (remember, most of the living cells in your body aren't even human), so for a time, those bacteria keep breaking down food. Even though peristalsis (the pushing of food through your digestive tract) stops, some things are still in motion.

My guess is that it's picking up these other movements. But whether I'm right or wrong about that, I'd still find it terrifying to see that report. It's natural to wonder...

[relietz]

Interesting. I would think, though, if it were detecting random movement and change, it would appear super erratic and not much like a gateways or pulse, not very rhythmic. Perhaps another theory could be that those low level residual electrical impulses, while not enough to trigger a heartbeat, are still enough to cause some small contraction of the arteries. This could move the blood slightly and look similar to the expansion and retraction that occurs with a heartbeat, even though the blood is not really flowing. While not enough contraction to be felt as a pulse, perhaps it would be enough to be visible to an optical sensor. Again, just a guess. Like you said, though, the cells and microbes in the body don't just all stop at once, so there are probably many possible explanations for this phenomena.