AliveCor Announces Apple Watch 'Kardia Band' for Medical Grade EKG Analysis

[tw1080]

Not common around were I'm at. Also never seen one used in place of a Holter monitor.

I don't care for some of their marketing. They state it is the most clinically-validated mobile EKG available, but then read the fine print and it's only being compared to smartphone devices. I also don't care for the term medical grade. To me that makes it seem a little more then it is even though technically the term is accurate since it's FDA approved.

Don't get me wrong I think portable ECG's are great for people that have heart problems. It just a lot of doctors don't explain it's limitations to patient. Same with automated BP cuffs. Seems like no one explains that they can be inaccurate at times.

And you wouldn't see any device like this, or the Zio patch, used in place of a holter monitor. They are different tests with different goals in mind. This would be more akin to cardiac event monitoring, where a single lead is definitely a thing. The iRhythm Zio patch was first to market, I believe, at least as an effective option, but Medicomp, Medtronic, Cardionet - most of these companies have been working on a single lead technology, often they're impeded or discouraged by insurance reimbursements, not a lack of technology to do so. This type of device could certainly be useful in identifying Afib, Aflutter, SVT, PSVT and other arrhythmias. It would certainly be able to generate an AFib burden report in a patient with known AF. Two and Three lead systems have been around for years, but in most cases that third lead, if present at all, is a ground lead, and doesn't play a part in generating the rhythm strip, simply in reduction of noise. You need sensors able to read positive and negative impulses, they don't necessarily need to be all that far APART. A qualified EKG tech can adjust to read what they have, within reason, it's not impossible.
[doublepost=1458261882][/doublepost]

Kind of thinking the same. Someone earlier in the thread even stated you need a 12-lead to detect afib, which is completely false. I suppose I understand the skepticism, but 1-lead ECGs are not a new invention and have their place in medical diagnosis and monitoring of arrhythmias. Especially for transient conditions a doctor is unable to replicate the issue with the patient in the office hooked up to a machine with more leads.

They're not necessarily WRONG, but they are misunderstanding their terminology. You absolutely do not need 12 leads to detect AFib. You could DETECT AFib on a Lead 2 alone, which would then be followed up with a 12-Lead to confirm. Tests are diagnostic TOOLS. Doctors do the diagnosing. (Again, not a doctor, and I don't play one, but I've been responsible for interpreting thousands of AFib strips in my 10 years of experience. Initial testing and interpretation is, more often than not, done by people like me, not a doctor.)

 

[ohio.emt]

How is lead II generated, though? You can't just connect one lead and determine anything at all. If there's a second contact on the other side of the body, it's not referenced anywhere in this article. In fact, other articles seem to indicate that both contact points are in the watch wrist band. Even with sensors on opposite sides, I'm not sure how you would determine anything without those two leads being physically connected. Einthoven's original EKG machine required both leads be connected, as does every Holter/Event monitor I'm aware of. I think this is bunk.

One lead is on the inside of your wrist touching the arm you watch is on. The other lead is on the outside of the band and you have to touch it with part of your non watch hand arm.
[doublepost=1458268067][/doublepost]

And you wouldn't see any device like this, or the Zio patch, used in place of a holter monitor. They are different tests with different goals in mind. This would be more akin to cardiac event monitoring, where a single lead is definitely a thing. The iRhythm Zio patch was first to market, I believe, at least as an effective option, but Medicomp, Medtronic, Cardionet - most of these companies have been working on a single lead technology, often they're impeded or discouraged by insurance reimbursements, not a lack of technology to do so. This type of device could certainly be useful in identifying Afib, Aflutter, SVT, PSVT and other arrhythmias. It would certainly be able to generate an AFib burden report in a patient with known AF. Two and Three lead systems have been around for years, but in most cases that third lead, if present at all, is a ground lead, and doesn't play a part in generating the rhythm strip, simply in reduction of noise. You need sensors able to read positive and negative impulses, they don't necessarily need to be all that far APART. A qualified EKG tech can adjust to read what they have, within reason, it's not impossible.

Trying to figure out why you replied this to me. I never said they are or would be used as a holter monitor, I was replying to someone else's post. I also said it would be a good thing for people with heart conditions. I also never said it wouldn't work.
[doublepost=1458268266][/doublepost]

I have done several medical device designs. From that, I really question the reliability of taking an ECG from any of the human bodies four limb ends.

As the pressure wave of a heart beat travels from the cardiac chambers, the R-wave (that big spike you see in an ECG) is really diminished after going through all the continually smaller blood vessels making to the wrist. This is classic fluid dynamics.

I'm sure with a press announcement like this, there will be third party petitions questioning the reliability of such a device making claims to read an ECG at the end of a human limb. If they are making any waveform reconstruction claims, the FDA will really put the screws to them as that can introduce a lot of false interpretations.

Also, whenever you go from "number to waveform", the FDA gets really inquisitive looking at the accuracy of the readings. My guess is the FDA will not approve this device and it will be sold overseas in places where claims are not so questioned.

Don't really know how pressure waves and fluid dynamics play into obtaining an ECG.

 

[tw1080]

One lead is on the inside of your wrist touching the arm you watch is on. The other lead is on the outside of the band and you have to touch it with part of your non watch hand arm.
[doublepost=1458268067][/doublepost] Trying to figure out why you replied this to me. I never said they are or would be used as a holter monitor, I was replying to someone else's post. I also said it would be a good thing for people with heart conditions. I also never said it wouldn't work.
[doublepost=1458268266][/doublepost]Don't really know how pressure waves and fluid dynamics play into obtaining an ECG.

They don't. EKG (or ECG) is strictly based on the electrical impulses generated, fluid doesn't come into play at all.

 

[CFreymarc]

One lead is on the inside of your wrist touching the arm you watch is on. The other lead is on the outside of the band and you have to touch it with part of your non watch hand arm.
[doublepost=1458268067][/doublepost] Trying to figure out why you replied this to me. I never said they are or would be used as a holter monitor, I was replying to someone else's post. I also said it would be a good thing for people with heart conditions. I also never said it wouldn't work.
[doublepost=1458268266][/doublepost]Don't really know how pressure waves and fluid dynamics play into obtaining an ECG.

The entire human body is one big electrochemical construct of both rigid and flexable materials. All forms of matter flow through it changing the electrochemical properties. An ECG is measurement of electricial characteristics from electricity flowing through tissue and fluids of different densities.

 

[Thai]

Just got email from AliveCor...the band is NOT waterproof. Bummer.

 

[Dave00]

You're missing the point of such devices. This does NOT replace Holter or EMs. It does NOT replace 12-lead ECG. This yet another CONVENIENT tool that patients (and indirectly doctors) use to diagnose a conduction issue or evaluate effectiveness of treatment, especially in someone who has paroxysmal conduction issues.

It is like camera analogy...of course Canon 5D takes better pictures than my iPhone. But my iPhone is always with me to take impromptu pics. The best camera is the one that you have with you, right?

Same for AliveCor phone case and Watch band. It is using (via add-on) what you ALREADY carry with you every minute of the day. Even Holter can be difficult if patients have arrhythmias beyond the monitoring period.

And given that their phone case has gotten FDA approval via PMA (strict testings), then these portable devices are ADEQUATE medical grade devices. There is no argument on this. The Watch band is using the same tech as the AliveCor phone cases and thus should pass 510k clearance easily. And yes, this is medical grade.

I misunderstood the claim, which I took to be continuous rhythm monitoring (continuous monitoring being far more useful for the stated purpose of looking for atrial fibrillation and other arrhythmias, which are often transient and gone by the time monitoring could be initiated.) I get your analogy of DSLR vs. convenient camera, but this is an area where accuracy is far more important than convenience. Your signal-to-noise ratio using a wrist lead and a finger lead (the off hand being used as the other lead by touching the sensor on the watch) is going to be very low. Computer interpretations of rhythm are already problematic with a good signal.

I would not look at FDA approval as terribly significant. Yes, it is difficult to get FDA approval, but that's mainly because the FDA is shamefully understaffed and underfunded. There's a long list of FDA-approved devices and medicines that never should've been approved and have since been recalled, and others that remain on the market despite severe methodological flaws in the studies that led to their approval.

When you're looking for arrhythmia, you start with a Holter, then an event monitor. If both of those fail and your level of concern is high, you go to an implantable loop recorder. I suppose one might get lucky and find an arrhythmia using this device, but the more concerning possibilities are (a) someone using the device in lieu of a reliable method and thinking everything is fine when it is not, and (b) the device misreading noise as a-fib and a person being placed inappropriately on anticoagulants.

 

[Thai]

I misunderstood the claim, which I took to be continuous rhythm monitoring (continuous monitoring being far more useful for the stated purpose of looking for atrial fibrillation and other arrhythmias, which are often transient and gone by the time monitoring could be initiated.) I get your analogy of DSLR vs. convenient camera, but this is an area where accuracy is far more important than convenience. Your signal-to-noise ratio using a wrist lead and a finger lead (the off hand being used as the other lead by touching the sensor on the watch) is going to be very low. Computer interpretations of rhythm are already problematic with a good signal.

I would not look at FDA approval as terribly significant. Yes, it is difficult to get FDA approval, but that's mainly because the FDA is shamefully understaffed and underfunded. There's a long list of FDA-approved devices and medicines that never should've been approved and have since been recalled, and others that remain on the market despite severe methodological flaws in the studies that led to their approval.

When you're looking for arrhythmia, you start with a Holter, then an event monitor. If both of those fail and your level of concern is high, you go to an implantable loop recorder. I suppose one might get lucky and find an arrhythmia using this device, but the more concerning possibilities are (a) someone using the device in lieu of a reliable method and thinking everything is fine when it is not, and (b) the device misreading noise as a-fib and a person being placed inappropriately on anticoagulants.

How long can the tiny battery in the sensor lasts if continuous?!!

This device is NOT definitive in diagnosing anything. It allows for the user to correlate his symptoms with any arrhythmia (if any). The threshold for these devices is set low. If anything, these devices get someone into the doctor's office that may need help.

To get placed on anticoagulants, this requires user to see a DOCTOR, right? No doctor will rely solely on this to make diagnosis and treat. You're exaggerating! The doctor will then do proper testing. And if noise, then OK. BUT, if it is not noise, then this AliveCor device just brought someone to the doctor's office who needed medical help...who otherwise would not even step foot into a medical facility.

Now, how about this scenario...a doctor put user on medications for Afib. How do you know that the meds are working? This device provides a nice feedback. User can see if his/her Afib is controlled...but that is easy with any HR device. But now He/she can see if he is still in Afib (when symptomatic or not)...if he/she was given anti-arrhythmic medication. User can see if he is in Afib after exercise or after a stroll in park.

Being FDA approved may not mean much but it means that it at least provide fairly reasonable accuracy (meet bare minimum requirement set by FDA).

It is like those car crash tests. Most cars nowadays pass with flying colors. Does this mean that you will not die in any crash? NO. It just means that a car has met minimal safety requirements. It does not guarantee that you will not die or get injured in a crash...but that it has the basics OK.

 

[Dave00]

To get placed on anticoagulants, this requires user to see a DOCTOR, right? No doctor will rely solely on this to make diagnosis and treat. You're exaggerating! The doctor will then do proper testing. And if noise, then OK. BUT, if it is not noise, then this AliveCor device just brought someone to the doctor's office who needed medical help...who otherwise would not even step foot into a medical facility.

The problem is, noise can look just like a bad arrhythmia. Then as a doctor, you're faced with trying to decide whether to believe the reading on a substandard device or whether to wait until you can identify something on a better test like a holter or event monitor. Guess wrong, and the person's next arrhythmia may be fatal. But if you believe the device and it's wrong, the person gets an invasive procedure to install a $50,000 defibrillator that isn't necessary. Bad data is often worse than no data at all.

 

[Thai]

You're not in the medical profession i assume. You're wrong on all counts. Just let the professionals handle this, ok?

Again: No doctor will rely solely on this to make diagnosis and treat. You're exaggerating! The doctor will then do proper testing. And if noise, then OK. BUT, if it is not noise, then this AliveCor device just brought someone to the doctor's office who needed medical help...who otherwise would not even step foot into a medical facility.

BTW, how do you know that this device is SUBstandard????? Have you used one? How does the band feel on your wrist since you have one already??

 

[Thai]

Digging thru AliveCor website, here are some research behind the tech: http://www.alivecor.com/research/

In particular: http://www.abstractsonline.com/Plan...9&mKey={BAEF2DB4-7615-4F2C-851A-E5D7461EBD4E}

Results/Applications
In 62 patients, 2 physicians found the QRS morphology to be the same between device recordings, though the iPhone-based ECG had more baseline noise than the standard ECG (Figure 1B). The mean/SD of the R-wave amplitudes for the standard and iPhone recordings respectively were 0.77/0.24 (mV) and 0.78/0.24 (mV), P<0.0001. In the 5 patients with pacemakers, pacing spike artifacts were clearly identified in all 5 enabling verification of pacing capture (Figure 1C).

Next Steps
The iPhone-based event recorder is an accurate clinical tool for ECG assessment and could prove to be a new tool for allowing immediate recording and analysis of an ECG rhythm.

[doublepost=1458834469][/doublepost]Good summary of the studies/research (from AliveCor site): https://alivecorcms.s3.amazonaws.co...s/53585600d4589c1897001dc9/files/00PL31_B.pdf
[doublepost=1458835118][/doublepost]

The problem is, noise can look just like a bad arrhythmia. Then as a doctor, you're faced with trying to decide whether to believe the reading on a substandard device or whether to wait until you can identify something on a better test like a holter or event monitor. Guess wrong, and the person's next arrhythmia may be fatal. But if you believe the device and it's wrong, the person gets an invasive procedure to install a $50,000 defibrillator that isn't necessary. Bad data is often worse than no data at all.

How could a device like this help? In the link above, there is a case study:

This is a single case study of a 22-year old admitted to the hospitalfor an episode of tachycardia at a rate of 150 BPM. Upon discharge from the hospital, the patient had an exercise ECG test in attempt to provoke the arrhythmia, then wore a 24-hour ambulatory ECG, and finally was issued a patient-activated event recorder for two weeks.

None of these methods captured abnormalities despite symptoms recurring approximately every three months.

The patient then purchased an AliveCor Mobile ECG and used this device to record a lead II ECG upon a subsequent attack of palpitations. A consultant cardiologist used this recording to diagnose probable atrioventricular nodal re-entrant tachycardia. Treatment followed.
[doublepost=1458835477][/doublepost]From links above:

Symptom rhythm correlation (85% vs. 30%, p=0.003) and the number of patients detecting and arrhythmia (45% vs. 10%, p=0.021) were both significantly higher with AliveCor than with Holter. The mean physiologist workload associated with Holter monitoring was found to be comparable with that of 12 weeks monitoring with AliveCor (39.3±19.2 minutes vs. 43±42.4 minutes, p=0.352). Of a total of 966 ECGs uploaded with AliveCor, 96% were interpretable with 4% uninterruptable through poor quality baseline and or presence of artifact.

The AliveCor Mobile ECG was found to be superior to conventional Holter monitoring in patients with palpitations, providing a higher diagnostic yield, more detected arrhythmias, and higher patient satisfaction, with a similar workload.
[doublepost=1458835656][/doublepost]More:

AF patients undergoing ablation (60 enrolled, 55 completed
study) were provided an AliveCor Mobile ECG and traditional
transtelephonic monitor. Patients were asked to record their
rhythm using both monitors simultaneously whenever they had
symptoms and at their weekly scheduled transmissions. AliveCor
Mobile ECG recordings had blinded reviews by an independent
electrophysiologist. Transtelephonic monitor recordings were
reviewed by the primary electrophysiologist. The kappa coefficient
was 0.82, indicating excellent agreement between the two
methods. The AliveCor Mobile ECG had 100% sensitivity and
97% specificity for detection of AF/atrial flutter compared to the
transtelephonic monitor. The AliveCor Mobile ECG can provide
an alternative method for monitoring AF patients after ablation
procedure. Most patients found the AliveCor Mobile ECG easy to
use and preferred it to the transtelephonic monitor.

 

[Praxiteles]

This can't possibly be accurate. My dad had a medical emergency last week. The EMTs started out with a four-lead ECG. They then switched to a 12-lead. The pads were dispersed all over his torso. The electrical signals travel from right to left across the heart. How could a wrist monitor (which might be on either wrist) perform the same function?

Here is the perspective of an emergency physician.

Kardia is accurate as a rhythm lead (i.e. roughly equivalent to Lead II on an EKG.)

12 lead EKGs are standard. 30 lead EKGs are even more accurate but aren't used in medicine.
The Kardia is accurate as a 2 lead EKG.

This means the Kardia is good for picking up rhythm disturbances (i.e. Atrial fibrillation, premature atrial/ventricular contractions, left and right bundle branch blocks, Mobitz type I-III rhythm disturbances, atrial flutter, ventricular tachycardia, and others) but will not pick up the ST segment and T wave changes typically needed to diagnose a heart attacks. You may see the arrhythmias occasionally associated with a heart attack.

 

[Praxiteles]

The problem is, noise can look just like a bad arrhythmia. Then as a doctor, you're faced with trying to decide whether to believe the reading on a substandard device or whether to wait until you can identify something on a better test like a holter or event monitor. Guess wrong, and the person's next arrhythmia may be fatal. But if you believe the device and it's wrong, the person gets an invasive procedure to install a $50,000 defibrillator that isn't necessary. Bad data is often worse than no data at all.

(Replying as an emergency physician.) Note that noise doesn't look like a bad arrhythmia. The noise would have to have a regular and consistent pattern which is virtually impossible to accidentally create. (You can see my answer below for the various arrhythmias that Kardia can pick up.) Google atrial flutter or left bundle branch block and you can see how precise the appearance of the rhythms appear.