Do you or anyone you know happen to have firsthand experience with the device?

There's no obvious cause, I'm fit and healthy in all other ways, I've had multiple blood tests and ECGs, my cholesterol is normal, everything is normal, just the blood pressure. I also didn't know about this machine but I might get one. I have developed anxiety around having it taken (because of the experience of getting sent to hospital!) so it goes up when I take it, like extreme white-coat syndrome.

I'm definitely getting one of these gadgets so I can see what it really is, without the stress and pain (those things hurt!) of inflating cuffs.

BP remains a great mystery to me, even with the device. My cardio fitness is pretty good despite carrying a few extra pounds (I'm in the low 50s for resting heart rate), and while overnight I dip down in the 120's, I can see it shoot up based on various things like cold plunge, caffeine, exercise (during), etc. I can also see it drop temporarily (hot tub, meditation, the hours FOLLOWING intense exercise, etc).

I had many pet theories through the years - that I had white coat syndrome, that I disliked the feeling of the cuff, etc etc. But the device showed me that, no, something really is going on independent of these pseudo-causes.

BTW water retention seems to play a big role. When I did keto, which causes a big drop in water retention, my BP also went down. Strange. Supplements have an impact too.

All this to say - get the device and see for yourself, but you might find yourself in the same place I am - which is that you have much better understanding of what's going on in terms of symptoms but are still on the search for "the underlying cause" if there even is such a thing.

Given enough data pairing continuous blood pressure with major events like heart attacks and strokes, we may even develop more accurate models to predict which types of spikes create the most cardiovascular risk.

As I typed the above sentence out, I thought "why not both?". Use the technology to reduce your risk, but in the event that the bad event still happens the notification could save your life.

I am particularly excited about the UT Austin research[1] that used conductive temporary tattoos to get actual real time data and not just polling at intervals. However it’s not yet at the stage of commercialization and the design is more the width of a cuff than a watch.

[1] https://scitechdaily.com/electronic-tattoo-offers-highly-acc...

This is a great point. Blood pressure readings are only useful in the context of stationary measurements under known conditions. Blood pressure is inherently volatile and depends on activity and recent movements, or to extreme events like cold exposure.

There are even finger-cuff blood pressure monitors designed for continuous, constant blood pressure measurement in the context of a lab or hospital setting. Their measurements would be useless in the context of someone moving around all day, but it can be useful in the context of someone under anesthesia or undergoing a controlled lab test.

This isn't fully true. For clinical reference to known "good" number ranges, then yes, you want to make the comparison as accurate as possible.

Butm there's a lot of potential unlocked with more data.

For example, we could discover that daily BP averages are more predictive than isolated doctor's office measurements. Imagine two people with equal BP measures at the doc's, but one has a more stressful job with higher average BP. We might reasonably expect them to have worse cardiac outcomes. Or consider the person who's anxious about docs and consistently shows higher numbers in the office than outside; we'd expect the reverse!

Another factor might be examining the variance. This already has precedents, since we know there are things that heart rate variability (HRV) correlate with more strongly than heart rate itself.

I was really hoping Apple was going to bring BP to the watch this year, but my guess is the regular external calibration requirement is too much for their plug-and-play philosophy.

Regular external calibration helped me build confidence. I was suspicions if the watch worked, and how well it worked. Calibration is every month - it expires. I take 3 measurements in parallel watch-cuff, and tell the watch App what the cuff measured. I didn't mind it initially. I now find it annoying tbh. I see why Apple would like to get rid of it. Post calibration, I measure 3 times in parallel both watch and cuff to check if they match. If the difference is within 5% - then fine. In 3 years it's happened twice where they differed more and I had to recalibrate. From recollection - both times with a reason, a TV was turned on in living room.

I have the impression that BP measurements differ though the day (lower in the morning, higher in the evening), depending on activity or at rest of course, I think there maybe some seasonality too (winter v.s. summer). Measuring BP when going to the doctor once a year strikes me as a wholly inadequate. If the BP is absurdly high out of normal range - then yeah, we learn something is wrong with the patient. But in any other case - don't see what can be deduced from 1 random measurement.

To check if the calibration is important, I had my wife use the watch, that is calibrated on me. She got absurd readings. So yes - the calibration is important and is tied to the person that did the calibration. (edited to add this)

Yeah, people panic reading a single 150 systolic, yet routinely it can reach 220+ during heavy exercise. It's perfectly fine. The health metric is the BP at rest, i.e. how low it goes when you're completely idle.

I find it takes up to 20 minutes to reach its lowest sometimes, in state of absolute calm: no movement, no talking, no anxiety. Hence the 'white collar hypertension', i.e. high BP when measured in hospitals and GPs office, where they don't give you enough time to settle down, or are not spaces that induce calm mental states.

The way I take my BP reading is every 5 minutes, until I get a similar reading after 2 consecutive measurements. It takes longer than you'd expect.

Did I eat late before bed? Higher BP overnight. Drink any alcohol at all after, say, 12pm? Higher BP overnight. So it's still useful and interesting to see the overnight values change and shift around.

However, the contrarian in my mind says that it's not smart to ONLY pay attention to your deep rest state BP, since that only applies to a fraction of the day. And if you're running around at high values for the rest of the day, you're still potentially doing damage to your kidneys, retinas, etc - the sensitive blood vessel stuff.

So it's a useful device, it's useful to have the data, but it's also still a bit of black box.

The fact that 80% of all high blood pressure is of unknown physiological cause is a real head scratcher considering that cardiac misadventures are the leading cause of death in the Western world.

Like many things, it is diet related. It seems "unknown" because GPs are still lagging well behind modern dietary research and are often nothing more than pill pushers. Lowering your sugar and simple carb intake over the long term, and fixing potentially hidden metabolic syndrome (see skinny fat people with unhealthy livers) is how you reverse it.

So while this may explain some amount (perhaps most?) of peoples idiopathic/essential HBP I doubt it's that simple.

"It's your potassium levels", "it's your homocysteine levels", "it's your fructose", "it's white-coat syndrome", "it's...." etc. Surely we're making progress but it's also not a silver bullet thing.

Good thing the treatments are so safe and effective.

Same thing with those continuous glucose monitors that almost anyone can get and put on their arm now. The vast majority of the data and recommendations we have are for diabetics using regular single use measurements or a proper glucose tolerance test so shortly after the user eats a bowl of rice while wearing it, it sends them into a hypochondriac spiral when they see a peak of 200. Their doctor generally has to talk them down. There's just not that much data on what the average healthy person's response to blood sugar is, especially when it's continuously monitored.

Chicken and egg situation, no?

People are advised not to use those devices because there isn't much data about them for otherwise healthy people. But if they don't use those devices, there won't be much data.

We already knew that things like weight fluctuated in normal people (periods, hydration, meals, etc), but many of us are still defaulting to the inaccurate model of slowly-changing measurements recorded 1x/2x a year at the doctor's office.

I'm sure people will get used to it, and many of the weight apps already wisely show averages to discourage fixating on individual measurements, but it feels like a missed opportunity.

There was a huge effect from perceived temperature--while I didn't do the cold plunge I got some quite high readings when I was on the chilly side. Yet I could get low-normal readings with my heart rate above 130 which is the highest I could go at that elevation. Obviously I couldn't actually take a reading while moving but I could have it on my wrist, stop and immediately press the button. The pattern I observed was activity raises temperature which lowers blood pressure.

My particular BP scenario is good diastolic, high systolic but low rest heart rate (low 50s). My pet theory is that my heart does fewer but stronger pumps, which increases the BP. After exercising, when heart rate remains elevated, the BP is lower since the heart is doing more frequent but less powerful beats.

Just a pet theory, I haven't even discussed it with a medical professional.

It would mean that you can literally show that working conditions are shortening your life.

Your company's health insurance could look at BP during commuting hours and in the office vs. at home and raise rates on companies based on their policies.

I wonder if you're calibrating on a supported arm, then letting your arm swing free later with the wrist device.

Looks interesting, but it too _requires_ a cloud account to function. WTH.

https://www.trustpilot.com/review/aktiia.com (2.9/5)

Labile hypertension is the most difficult to treat. So far my heart is perfect for a late 50's dude. Just had an colorflow echocardiogram, no sign of hypertension in the heart. Probably because I eat so much fish.

If I drink coffee my BP is up all day though. I am just very sensitive.

https://en.wikipedia.org/wiki/Labile_hypertension

I really freak out about getting my blood pressure taken in a clinical setting, it's really unusual.

I had some treatment for a kidney stone recently, and after the procedure they were checking me with some pretty accurate machines, like 10 times in 24 hours (apparently), 128/80, for some reason in that specific setting I didn't freak out.

White coat HT is a weird thing.

Wonder if you have noticed if you were neurologically sensitive to any types of foods?

I'm learning I just can't really do coffee / caffeine though, I don't think it's ever really been good for me, it causes reflux and anxiety for me, but I just loved coffee to much. I gave up recently however!

You might have heart burn occasionally too ?

But having worked in medical sensors, and spending time with researchers as customers, there was a real sense that they could learn a lot from BP readings that were accurate and continuous.