Tag Archives: AliveCor

What Is The Cause of Low Voltage (Unreadable or Unclassified) AliveCor/Kardia Mobile ECG Recordings?

The skeptical cardiologist has had several of his readers submit stories and tracings of AliveCor Mobile ECG recordings which yield unclassified or unreadable recordings. In some cases this is due to excess noise but a lot of these tracings suffer from low voltage: the height of the tracing is very small.

John, a skepcard reader, is typical.

Recently, he noted his heart was racing and made an AliveCor recording which came back interpreted by the app as normal

EKG-3
First tracing. Note the QRS complex (the large regular spikes) are 2 boxes high. Right in front of them is a little bump, the p wave indicating normal sinus rhythm

 

Three hours later he made a second recording which has drastically lower voltage: the only deflections visible are tiny QRS complexes, the p waves have disappeared. I think this is also normal sinus rhythm but because p waves can’t be seen this came back uninterpretable and if there were any irregularity AliveCor would have called it atrial fibrillation:

EKG-4
Second tracing. Note the QRS spikes now are less than half of a box tall. There are no consistent p waves visible (unless one has a good imagination). The bumps after QRS spikes are T waves.

John has a theory on the cause of some of his low voltage recordings which I shall reveal in a subsequent post after testing it.

In the meantime, if any readers have suggestions as to causes of low voltage recordings or have noted similar issues please comment below or send recordings and observations to DRP@theskepticalcardiologist.com.

Voltagophilistically Yours,

-ACP

 

 

 

 

Sustained Atrial Fibrillation or Not: The Vagaries and Inaccuracies of AliveCor/Kardia and Computer Interpretation of ECG Rhythm

The skeptical cardiologist has often sung the praises of the AliveCor Mobile ECG for home and office heart rhythm monitoring (see  here and here.) However, there is a significant rate of failure of the device to accurately identify atrial fibrillation.  I’ve seen numerous cases where the device read afib as  “unclassified” and normal sinus rhythm (usually with PVCs or PACs) called afib both in my office and with my patient’s home monitors.

In such  cases it is easy for me to review my patient’s  recordings and clarify the rhythm for them.

For those individuals who do not have a img_8322cardiologist available to review the recordings, AliveCor offers a service which gives an option of having either a cardiac technician or cardiologist review the tracing. The “cardiac technician assessment” costs $9 and response time is one hour. The “Clinical Analysis and Report by a U.S. Board Certified Cardiologist” costs $19 with 24 hour response time.

Obviously, I have no need for this service but I’ve had several readers provide me with their anecdotal experiences with it and it hasn’t been good.

One reader who has a familial form of hypertrophic cardiomyopathy utilizes his AliveCor device to monitor for PVCs. One day he made the following recording which AliveCor could not classify:
screen-shot-2017-02-14-at-5-37-42-am
screen-shot-2017-02-14-at-5-43-51-am screen-shot-2017-02-14-at-5-41-41-am

He then requested a technician read which was interpreted as “atrial fibrillation sustained.”

He then had requested the cardiologist reading which came back as Normal Sinus Rhythm.

Finally, he againscreen-shot-2017-02-14-at-5-44-09-am requested the technician
read and got the correct reading this time which is normal sinus rhythm with PACs

When my reader protested to Kardia customer service about this marked inconsistency: three different readings in a 24 hour period, a Kardia  customer service rep responded :

 I was able to review this with our Chief Medical Officer who advised that the recording shows Sinus Rhythm with PACs. The Compumed report seldom provides identification of PACs and PVCs as most cardiologists believe they are not significant findings. The sustained AFib finding was incorrect, so I have refunded the $5 fee you had paid.

Please let us know if you have any other questions.

As I pointed out in my post on palpitations, most PVCS are benign but some are not and patients with palpitation would like to know if they are having PVCS and/or PACs when they feel palpitations.

More importantly, the misdiagnosis of afib when the rhythm is NSR with PACs or PVCs can lead to extreme anxiety.

sr-pvcs-with-annotations
This tracing clearly (to me) shows regular and similar upward deflections (red arrow, p waves) which are a similar distance from the QRS complexes which follow (QRS complexes). The green arrows point to irregular deflections due to noise which can confuse computer algorithms (and non-cardiologists.) The distance between the QRS complexes is very regular (black arrow, RR interval). Thus, this is clearly normal sinus rhythm (NSR). Later in the recording PVCs (green arrows) are noted occurring every other beat. The distance between the QRS complexes on either side of the PVC is still the same as two RR intervals. This is clearly ventricular bigeminy.

Heres a recording
I made in my office this morning on a patient with cardiomyopathy and a defibrillator.

This is very clearly NSR with PVCs yet AliveCor diagnosed it as “possible atrial fibrillation.”

The AliveCor algorithm  is not alone in  making frequent errors in the diagnosis of atrial fibrillation.

The vast majority of ECGs performed in the US come with an interpretation provided by a computerized algorithm and medical personnel rely on this interpretation until it can be verified or corrected by an overreading cardiologist.

One study demonstrated that computerized ECG interpration (ECG-C) is correct only 54% of the time when dealing with a rhythm other than sinus rhythm

Another study found that 19% of ECG-C misinterpreted normal rhythm as atrial fibrillation. Failure of the physician ordering the ECG to correct the inaccurate interpretation resulted in change in management and initiation of inappropriate treatment, including antiarrhytmic medications and anticoagulation, in 10% of patients. Additional unnecessary diagnostic testing was performed based on the misinterpreted ECGs in 24% of patients.

When lives or peace of mind are at risk you want your ECG interpreted by a cardiologist.

I would like to take this opportunity to personally issue a challenge to IBM’s Watson.

Hey, Watson, I bet $1,000 I can Interpret cardiac rhythm from an ECG with more accuracy than you can!

Are you listening, IBM?

Do you copy, Watson?

-ACP

AliveCor Mobile ECG Update: Successes and Failures

The  AliveCor/Kardia mobile ECG device is a really nifty way to monitor your heart rhythm. Since acquiring the third generation device (which sits within or on my iPhone case and communicates with a smartphone app) I have begun routinely using it  on my patients who need a heart rhythm  check during office visits. It saves us the time, inconvenience (shirt and bra removal) and expense of a full 12-lead ECG which I would normally use.

In addition, I’ve convinced  several dozen of my patients to  purchase one of these devices and they are using it regularly  to monitor their heart rhythms. Typically, I recommend it to a patient who has had atrial fibrillation (Afib)  in the past or who has intermittent spells of palpitations.

Some make daily recordings to verify that they are still in normal rhythm and others only make recordings when symptoms develop.

Once my email invitation request is accepted I can view the ECGs recorded by my patients who have AliveCor devices as I described here.

This monitoring has in many cases taken the place of expensive, obtrusive and clumsy long term event monitors.

In general, it has been very helpful but the device/app makes occasional mistakes which are significant and sometimes for certain patients it does a poor job of making a good recording.

Alivecor Success Stories

One of my patients,  a spry ninety-something year young lady makes an AliveCor recording every day, since an episode of Afib 9 months ago.

And when I say every day I mean it literally everyday. It could be because she is compulsive or perhaps she has programmed the AliveCor to remind her. When I log in to the AliveCor site and click on her name I can see  these daily recordings:Screen Shot 2016-06-17 at 12.40.07 PM

After a month of normal daily recordings, she suddenly began feeling very light headed and weak with a sensation that her heart was racing.

Screen Shot 2016-06-17 at 12.41.13 PMShe grabbed her trusty iPhone and used the AliveCor device attached to it to make a recording of her cardiac rhythm. This time, unlike the dozens of other previous recordings, the device indicated her heart rate was 157  beats per minutes , about twice as fast as usual.

After 5 hours her symptoms abated and by the time of Screen Shot 2016-06-17 at 12.46.52 PMher next recording she had gone back to the normal rhythm.

She made two other recordings during the time she felt bad and they both confirmed Afib at rates of 140 to 150 beats per minute.

In this case, the device definitely alerted her to a marked and dramatic increase in heart rate but was not capable of identifying this as Afib In my experience with several hundred recordings, the device accurately identifies atrial fibrillation about 80% of the time. On rare occasions (see here) it has misidentified normal rhythm with extra beats as atrial fibrillation

Review Options

AliveCor/kardia users  have the option of having their recordings IMG_6936-1interpreted for a fee by a cardiologist or a technician.

My patients can alert me of a recording and I can go online and read the ECG myself and then contact the patient to inform them of my interpration of their heart rhythm and my recommendations.

Another patient made the recording below:Screen Shot 2016-06-18 at 11.32.26 AMAlthough she is  at high risk of having a stroke during the times she is in Afib, we had been holding the blood thinner I had started her on because of bleeding from her mouth. I had instructed her to take daily recordings of her rhythm with the AliveCor until she was seen by her dentist to evaluate the bleeding.

In this case, the AliveCor performed appropriately, identifying correctly the presence of Afib which was the cause of her nocturnal symptoms.

AliveCor Failures

A young woman emailed me that her AliveCor device on several screen-shot-2016-11-27-at-5-18-23-amoccasions has identified her cardiac rhythm during times of a feeling of heart racing and palpitations as “possible atrial fibrillation.”  When she sent the recordings in to AliveCor to have a paid interpretation, however, the recordings were interpreted as sinus tachycardia with extra beats.  Indeed , upon my review her rhythm was not Afib. Clearly, when the device misidentifies Afib, this has the potential for creating unnecessary anxiety.

It is not uncommon for a full, 12-lead ECG done in the hospital or doctor’s office  by complex computer algorithms to misinterpret normal rhythm as Afib so I’m not surprised that this happens with AliveCor using a single lead recorded from the fingers.

The young woman was advised by AliveCor to try a few things such as using the device in airplane mode, sitting still and wetting her fingers which did not help. She was sent a new device and the problem persisted. She finds that putting the device on her chest gives a better chance of success.

She also runs into a problem I see frequently which is a totally normal recording labeled by the device as  “unclassified.”screen-shot-2016-11-27-at-5-35-05-am

In this example, although I can clearly see the p-waves indicating normal sinus rhythm, the voltage is too low for the device to recognize.

Send Me Your AliveCor Problems and Solutions

I’m interested in collecting more AliveCor/Kardia success and failure stories so please post yours in the comments or email me directly at DRP@theskeptical cardiologist.com.

In addition, I’m interested in any tips AliveCor users have to enhance the success of their recordings: What techniques do you use to make the signal strength and recording better? What situations have you found that tend to worsen the signal strength and recording quality?

Still Unclassified Yours,

-ACP

P.S. Tomorrow is Cyber Monday and I note that Kardia is running a “Black Friday” special through 11/28, offering the device at 25% off.

screen-shot-2016-11-25-at-6-00-14-amP.P.S. Kardia, You should change the statement on your website, “90% of strokes are preventable if you catch the symptoms early.”  makes no sense. I think you mean that some strokes are preventable (I have no idea where the 90% figure come from) if one can detect Afib by utilizing a monitoring device to assess symptoms such as palpitations or irregular heart beat.

 

 

Getting To The Heart Of Father’s Day

The skeptical cardiologist received an email from the folks at AliveCor a few days ago with the subject line:

Dad’s heart matters – Kardia Mobile for Dad will give you peace of mind and make Dad happy

The email contains this image of an older well-dressed man (withScreen Shot 2016-06-18 at 9.03.26 AM lots of bling) standing in a beautiful meadow near the ocean. The man has decided to turn his back on the ocean and check his heart rhythm using the AliveCor/Kardia (AliveCor has changed the name of its ECG devices to Kardia) mobile ECG. This man is a happy dad! (Unless his heart rhythm is interpreted as atrial fibrillation. Then the beach walk is ruined.)

The email asks the question “What if Dad’s heart really was an open book?”

Uhh, he’d be dead? Clearly books don’t function well at pumping 5 or 6 liters of blood through the cardiovascular system every minute whether they are open or closed. Perhaps  the question is using either  the heart or an open book as a metaphor?

The advertisement goes on to suggest that I get my dad an AliveCor device for father’s day  “So you always know what his heart is thinking.”

I believe this is the marketing person’s attempt to extend the metaphor of the open book, i.e., you know exactly what dad’s brain is thinking, now you can extend this knowledge to his heart.  The metaphor of the heart “thinking” is quite poor but poor metaphors are the norm today.

Bad metaphors and bad writing abound on father’s day because 90 million greeting cards are purchased and given as (according to the Greeting Card Association)  “a meaningful expression of personal affection for another person.” Despite the increasing use of Facebook and its ilk to transmit emotions, the Greeting Card Association assures us that “The tradition of giving greeting cards … is still being deeply ingrained in today’s youth, and this tradition will likely continue as they become adults and become responsible for managing their own important relationships.

Mobile Ecg Monitor As A Father’s Day Gift

I have to say that despite the horror of the writing in this email advertisement it got me thinking about getting my father a Kardia device. I’ve suggested  previously that  an AliveCor device would make a good gift for Christmas for a loved one who has intermittent unexplained palpitations or atrial fibrillation but had not considered this for my dad.

For one thing he does not possess a smart phone which is required to  make the Kardia device functional. For another, he doesn’t have atrial fibrillation (that we know of. Perhaps if I knew what his heart was thinking we would find out that it likes to fibrillate late at night,)

Perhaps it’s time to upgrade my Dad to an iPhone I began thinking.

But wait! He has an iPad mini (that he seems to only use for FaceTime conversations.)

Further research reveals that Kardia is not only compatible with iPhone and Android smartphones but apparently iPads and IPod Touch.Screen Shot 2016-06-19 at 8.04.27 AM

Taking Care of Dad’s Heart

What about the rest of the slick advertising copy in my email?

And now you can know the way to help take care of it. Kardia gives Dad a medical-grade EKG in only 30 seconds. It even gives him expert analysis and tracking, with reports getting shared directly with his physician

This part is pretty clear and correct. I use Kardia daily in my office to record patient’s heart rhythm and I have a dozen patients now who make recordings outside of the office. They can have their recordings read by a random cardiologist for a fee or establish a link with me as their provider and I can review them through my account for free.

 Is It The First Father’s Day Gift That Leads To More Father’s Days?

The ad ends with the remarkably brazen statement that “It’s the first Father’s Day gift that leads to more Father’s Days.”

While I find the device more helpful in many instances than current expensive and intrusive long term monitoring devices for detecting and monitoring atrial fibrillation and other abnormal heart rhythms, it is a huge leap to suggest that this translates somehow into a longer life span.

To AliveCor’s credit, despite such ridiculous marketing drivel , studies presented at the recent Heart Rhythm Society Scientific Meetings suggest:

  • Kardia Mobile Superior to Conventional Monitoring: Researchers at the Leeds General Infirmary found that the AliveCor monitor is superior to conventional Holter monitoring in patients with palpitations, providing a higher diagnostic yield, more detected arrhythmias, with a similar workload.

  • Kardia Mobile Leads to Improved Patient Compliance:Researchers at the University of Buffalo found that AliveCor provides a diagnostic yield comparable to a 30-day ambulatory looping event monitor and that the smartphone-based ECG monitor can be used as a first approach for the diagnosis of palpitations.

  • Kardia Mobile provided more information resulting in changes in arrhythmia patient management than traditional external event recorders in a study from researchers at the University of Miami.

  • AliveCor’s AF algorithm was reported to be superior by researchers at Arizona State University to the patient’s own ability to detect AF via symptoms.

    But even if these studies make it to publication they don’t suggest the device provides any improved longevity. In fact, such data, do not exist for any monitoring device.

Happy Father’s Day, Dad! Don’t be surprised when we FaceTime later today that I’ve found another use for your iPad.

Paternally Yours,

-ACP

N.B. Clearly I receive no consulting, speaking or P.R. writing fees of any kind from AliveCor. Nor do they provide me with any free devices. What’s more, when I lose one of their devices they don’t replace it.  I am totally free of any conflict of interest.

 

What Happens If You Go Into Atrial Fibrillation On A Cruise?

This question popped into my head as I was talking to a patient (we’ll call her Barb)  who has paroxysmal atrial fibrillation (PAF) and was about to embark on a 17 day cruise from San Diego through the Panama Canal and on to Fort Lauderdale.

Screen Shot 2016-04-11 at 6.12.04 PM
The recording I pulled up shows atrial fibrillation going at a rapid rate.

On a rainy Sunday afternoon while watching the Cardinals pummel the Braves, I had logged onto my AliveCor account to pull up some office patient recordings I had made earlier in the week when I noticed that Barb had made a recording the day before which was interpreted as atrial fibrillation at a rate of 133 beats per minute. I had heretofore been aware that she was having  recurrent episodes of PAF and so I called her and found out she was in San Diego.

At her last office visit in early March she was in normal rhythm as usual but reported having spells of palpitations, usually at night. We discussed various monitoring methods and I demonstrated the Alivecor device to her. She purchased one and had been making recordings but had not let me know that some of them were showing atrial fibrillation.

Fortunately, she was on the blood thinner Eliquis and  was protected against clots in the heart or stroke but I was worried that she might go into Afib on the cruise, persist in it and develop problems.

What, I wondered, would the cruise ship crew or doctor do in that situation?

Would  they be capable of even monitoring my patient’s heart rhythm or would the AliveCor Mobile ECG device she had on her smart phone be the best monitor on the ship?

Are there any medications, like beta-blockers available that could be given to slow the heart rate?

I’m still waiting for the answer to the questions.

What Do We Know About Medical Care on Cruise Ships?

No so much.

Consumer Reports has an informative  article entitled:  “What you need to know about medical care on cruise ships.”

The middle four items are relevant to any cardiac issue:

“-Cruise ships aren’t hospitals

Many ships have a doctor on board who is trained in emergency medicine—but not all of them. According to international maritime law, they aren’t required to; a crew member with medical training is sufficient, says Ross Klein, Ph.D., author of “Paradise Lost at Sea: Rethinking Cruise Vacations.” The medical facilities are generally more like an infirmary or walk-in care clinic than a “floating” hospital. You might find a ventilator and a small X-ray machine and the doctor may be able to perform simple laboratory tests to check for infection or electrolyte or blood sugar levels. But there’s no MRI or CT scanner, intensive care unit, or blood bank (although the crew has usually been blood-typed and may be asked to serve as donors if a passenger needs a transfusion).

– In an emergency, you may be on your own

. You probably could get basic treatment, such as stitches or IV fluids, but for anything serious, there’s a very good chance that you will have to disembark at the next port of call—whether you want to or not. It’s up to the ship’s medical personnel, not you, to decide, You’d be treated at a local hospital, and the ones in more remote areas may not have the same standards of medical care or facilities available in the U.S. And once you recovered, you’d have to arrange another way to get back home.

What if you have a heart attack or develop appendicitis miles from dry land? Don’t assume the Coast Guard will airlift you out. Bad weather can make flying a helicopter dangerous, and the Coast Guard isn’t obligated to take that risk. Even in calm waters, if the ship is 500 miles or more away from shore, it’s unlikely that the Coast Guard will respond, Klein said.

-Get ready for sticker shock

Check with your health insurance company before you set sail to be sure, but most plans don’t cover medical services you get on board, … (In fact, this is usually the case anytime you receive medical treatment from a doctor or hospital outside the U.S.) This means you pay out-of-pocket. The bill can range from a few hundred to several thousand dollars…

Travel health insurance is your best protection. Consumer Reports recommends avoiding commission-driven policies sold by tour operators, cruise-line representatives, and travel agents. Instead check out an online broker, such as insuremytrip.com, that sells coverage from multiple companies and allows you to tailor a plan to your needs. Ask for quotes, but be sure you’re comparing apples to apples. What’s covered under policies can vary. For example, some may not include emergency evacuation.

-Your Ship Does Not Have A CVS

Most ships do have common prescription drugs on board, but you can’t count on it. What’s more, if you needed one, you’d be charged full price—not just your insurance co-pay—for each drug dispensed on the ship.

The Plan

I developed a plan for my patient and called in a prescription for her to fill prior to getting on the Celebrity Infinity.

Then I tried to get some information on what medical support would be available on her ship.

I called  Celebrity Cruise Lines to see if they had a doctor and whether I could communicate with him.  I was immediately told yes, however when I asked what the doctor’s qualifications and if I could talk to him this was apparently a novel request. After multiple transfers I spoke to someone in “Special Needs” who gave me an email address. I’m told by email that they have my contact info and the doctor will contact me if needed.

At this time, I’m assuming Barb is on the Celebrity Infinity and cruising down the Pacific Coast of Mexico, enjoying the cool ocean breezes and lounging by the ship’s pool.

Hopefully she won’t have a prolonged episode of afib that needs any urgent medical care.

If she does or if the cruise ship doctor gets back to me,  I may get that information I’ve been seeking on  how cardiac urgencies and emergencies are handled on cruise ships and I will be sure to share it with all of you.

Nautically Yours

-ACP

 

 

 

 

AliveCor Is Now Kardia and It Works Well At Identifying Atrial Fibrillation At Home And In Office

I’ve been using the AliveCor Mobile ECG App/Device to record my patients’ heart rhythm in my office for about 6 months now.

It has for the most part taken the place of the more elaborate, but cumbersome and time-consuming, 12-lead ECG in patients where heart rhythm is my only concern.

I’ve also convinced about a dozen of my patients who have intermitent atrial fibrillation to obtain the device and they are actively using it to monitor at home their heart rhythm. Through the AliveCor website, I can view their recordings and see what their heart rhythm is doing when they have symptoms.

Last week, a patient of mine (I’ll call her Suzy) who has had significant prolonged episodes of atrial fibrillation associated with heart failure (but cannot tell when she is in or out of rhythm) notified me that her device was interpreting her rhythm as atrial fibrillation. She had not had any symptoms, but was making  daily recordings for surveillance.

Suzy called our office and we brought her in the next day and confirmed with a 12-lead ECG that she was indeed in atrial fibrillation with a heart rate of 120 beats per minute.

It’s pretty amazing that this little, inexpensive device can now replace expensive and elaborate long term cardiac monitors for many of my patients.

AliveCor Rebrands Itself to Kardia


Screen Shot 2016-03-28 at 5.38.34 AM
I’ve noticed that AliveCor has rebranded itself as Kardia. If you go to http://www.alivecor.com now you see the fourth generation device along with promotion of a “Kardia band” which apparently works with an Apple Watch to record your ECG.

The Kardia band is not available for purchase at this time but if and when I can get one, it might motivate me to purchase an Apple watch.

When I purchased my AliveCor device in June, 2015 it cost $74.99 from Amazon.com. The newer version is priced at $99 at both AliveCor and Amazon websites. I’m told by Dr. David Albert of AliveCor that this “fourth generation” version is more accurate, so I have purchased it to see if it reduces the problem of occasional bad recordings.

Screen Shot 2016-03-28 at 5.38.10 AM

You can see in this picture from the website that the formerly flat metal electrodes now have bumps. Dr. Albert says these result in more surface area for better contact with skin. We will see.

The Value of Early Detection Of Atrial Fibrillation

Meanwhile, I will be doing an electrical cardioversion (shocking or resetting the heart) on Suzy to get her back to normal sinus rhythm.  If we had not detected the asymptomatic onset of her rapid atrial fibrillation using the AliveCor/Kardia device, chances are we wouldn’t have known about it until her heart muscle weakened again and she became short of breath from heart failure.

I have Suzy on blood thinners to lower her risk of stroke associated with her Afib but for my patients who are not on blood thinners, detection of silent or asymptomatic AFib is even more important.

-Affibly yours,

-ACP

p.s. The skeptician in me feels this post borders on infomercialese.

Let me make it clear that I have no connection with the company formerly known as AliveCor and have received nothing from them (not even free test devices or Apple Watch Kardia Bands!) but I’m just really excited about the device and how it can help my patients (oh, please excuse me, this really sounds like marketing) “empower” themselves to take control of their heart rhythm.

In the course of writing this, I’ve discovered an academic paper evaluating 13 ECG smart phone type ECG devices so there are other devices you could try. I haven’t had the time or resources to evaluate them.

The Perfect Christmas Gifts for the Palpitating or Hypertensive In Your Life

As December draws ever closer to the twenty-fifth you may find yourself  behind the wheel of a large automobile puzzling over the perfect gift for your loved ones.

Fear not, for the skeptical cardiologist has a few suggestions to help you.

The Omron 10 Blood Pressure Monitor

IMG_5618
EXTRA-LARGE digits with backlight!!

If your hypertensive friend or relative already has all the standard BP paraphernalia (pill splitter, basic BP cuff), owns a smart phone and has an engineer or scientist approach to data the Omron 10 (BP786, 59.99$ at Best buy.com) just might be the perfect gift.

The skeptical cardiologist recently purchased two (that’s right two) of these in anticipation of Christmas.

Christmas arrives with multiple stressors guaranteed to hike your blood pressure.

The Omron 10 offered three features not available on my basic Walgreen’s BP cuff that I felt were possibly useful:

  1. Averaging/automating three consecutive readings. After reading about the SPRINT BP trial which showed a benefit of aiming for SBP of 120 over 140,  I thought I should try to reproduce the method used in the trial. This involved measuring BP 3 times separated by 5 minutes and averaging the results. The Omron 10 can be set to make and average three BP readings separated by a variable time period.
  2. The ability to communicate with an iPhone or Android smartphone and record and display the data in an app.
  3. Works off both batteries and plug in electrical power.

I thought my dad (a retired chemist) would like the Omron 10’s features but, alas, he informed me that if he wanted to average three BP readings he could just write down the numbers and do the math.

IMG_5670If he had an iPhone he might really like the way the Omron sends its data to the free Omron app.

The app displays BP  and heart rate readings recorded for different time intervals.

You can take a screen shot like I did here or email it and share the data with your doctor through the doctor’s patient portal!

 

The AliveCor Mobile ECG

IMG_6936 copyI’ve mentioned this really cool device a few times (here and here).

It is now listed on Amazon.com for $57 (a significant drop from when I purchased it)  and can be attached to your smartphone case. It does a really good job of recording a single lead electrocardiogram (ECG) and diagnosing normality or atrial fibrillation.

If your friend or loved one  is experiencing periodic fluttering in their chest or a sensation of the heart skipping beats or racing (the general term for which is palpitations) then this could be the perfect gift.

A number of my patients have purchased these and have made ECG recordings which I can review online.

Primarily I have been recommending them to my patients who have atrial fibrillation periodically.

You may think this is too complicated a device to master but last week I saw in my office a 94 year old lady who had had an episode of atrial fibrillation earlier in the year.  Since her last visit she had purchased an AliveCor device and was able to show me the ECG recordings she had made on her iPhone.

May your holiday season be joyous, full of loved ones and free of stressors that raise your blood pressure and cause your heart to pound and race. But if it is not, consider purchasing one of these nifty devices.

Same as it ever was

-ACP

 

 

AliveCor Mobile ECG Misidentifies One Patient’s Heart Rhythm

The skeptical cardiologist has been evaluating the AliveCor mobile ECG device for use with a smartphone to detect atrial fibrillation.  In my initial post on this I found it to be accurate in identifying atrial fibrillation in my patients.

The AliveCor stuck (in a very crooked fashion) on the back of my (not particularly clean) iPhone 6 and ready to record YOUR heart rhythm.
The AliveCor stuck (in a very crooked fashion) on the back of my (smudgy) iPhone 6 and ready to record YOUR heart rhythm.

I’ve been using it in my office fairly regularly and encouraging my patients with intermittent AF to acquire the device and use it to monitor their heart rhythm.

When they make recordings they can be uploaded to me via internet for my review.

The other day I was examining a patient who I was seeing for syncope (passing out) and I noticed when listening to his heart that his pulse was very irregular.

I pulled out my iPhone with AliveCor stuck on the case and made the recording you see below. Screen Shot 2015-09-08 at 2.24.05 PM

Although the AliveCor app diagnosed it as “possible AF” it is very clearly normal sinus rhythm with frequent premature ventricular contractions (PVC), a totally different (and more benign) rhythm.

I’ll continue on with this evaluation and I’ll be particularly interested in how AliveCor performs in other patients with PVCs which are a common cause of palpitations in the general population.

If AliveCor cannot differentiate AF from PVCS it may lead a lot of users to become unduly concerned about their heart rhythm.

palpitatingly yours

-ACP

 

AliveCor Smartphone App Detects Atrial fibrillation: Potential for Stroke Prevention

Atrial fibrillation (AF)  is a common abnormal rhythm of the heart which causes 1 in 4 strokes. Those afflicted with AF may lack any symptoms or only have a vague sense of irregularity of their heartbeat and thus the first symptom of AF can be stroke.

The gold standard for diagnosing AF has long been the electrocardiogram (ECG or EKG) and typically the ECG involves placing 12 electrodes on the chest/arm/legs and recording the electrical activity of the heart on an expensive device.

I’ve been checking out a device made by Alive Cor which works with your smart phone to record a single channel ECG and is capable of accurately diagnosing if you are in the normal (sinus) rhythm or in AF.
Screen Shot 2015-07-12 at 8.45.49 AMYou can purchase the third generation (significantly smaller then earlier versions) AliveCor Mobile ECG from Amazon or from AliveCor directly for 74.99$ and it works with an app with both iOS and Android devices.

I used mine with my iPhone 6. At first I carried it separately, fearing the added bulk when stuck on to my iPhone case but after a while I realized that it was never with me when I wanted to use it and that there was a huge risk of losing it and so I used the backing adhesive to attach it to my case.

After pairing the device with the app you put two fingers on each of the metal pads and the smartphone screen displays the recording. After 30 seconds of recording it then interprets the rhythm.

Screen Shot 2015-07-12 at 8.56.47 AM
Typical recording in normal sinus rhythm. The red arrow indicates the small p waves which are the electrical signal of the upper chambers (the atria) depolarizing , the blue arrow indicates the electrical depolarization of the ventricles (QRS). The orange arrow indicates that the time interval between the QRS complexes is the nearly the same for each beat, indicating the regularity that we expect when in NSR compared to AF.

Above is a typical recording I made in my office on a patient who had a history of AF. The quality is good and I can clearly see that he is in normal sinus rhythm. The app correctly made the diagnosis of NSR and calculated his heart rate at 68 beats per minute.

One day I had most of my patients record their ECG’s using AliveCor and compared it to the standard 12-lead ECG we normally record. The device correctly identified the two patients with AF out of this group and correctly identified the normals.

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AliveCor recording of patient with AF with heart rate of 70 beats per minute. Note the absence of p waves before the QRS complexes and note the beat to beat variation in the RR interval (orange arrow)

This recording is from a patient with persistent AF which had recurred two weeks earlier. The device correctly identified AF.

Studies have documented that AliveCor Mobile ECG can accurately diagnose AF in a screening setting and the FDA approved the device for AF screening in 2014.

Given the high prevalence of silent AF, the strong association of AF with stroke and the availability of anticoagulants which reduce AF associated stroke by 70%, screening for AF with devices like AliveCor holds the promise of preventing large numbers of stroke.

(For my comments on taking the pulse and stroke prevention see here and on the inadvisability of a routine 12-lead ECG see here)

AliveCor allows physicians utilizing the Mobile APP and ECG to have a “dashboard” into which their patients can transmit their AliveCor ECG recordings.

I will be discussing this remarkable new device with my AF patients  who are smartphone enabled. I think it will advance our ability to more efficiently and quickly diagnose AF in them.

My standard approach if a patient with AF calls and says that they feel like they are out of rhythm is to have them come into the office for a full 12-lead ECG. If they are AliveCor enabled, they could make their own recording, and we could review that remotely and make a diagnosis without the office visit.

Let me know your thoughts on smartphone ECGs.

fibrillatorily yours,

-ACP