Tag Archives: atrial fibrillation

Review of Kardia Band Mobile ECG for Apple Watch

The skeptical cardiologist has been evaluating the Kardia Band from AliveCor which allows one to record single lead medical grade ECGS on your Apple Watch. What follows is my initial experience with setting up the device and using it to make recordings.

After ordering my Kardia Band for Apple Watch on 11/30  from AliveCor the device appeared on my door step 2 days later on a Saturday giving me most of a Sunday to evaluate it.

What’s In The Box

Inside the box I found one small and one large black rubber wrist watch band

The larger one had had a small squarish silver metallic sensor and the smaller one had a space to insert a sensor. It turns out my wrist required the smaller band and it was very easy to pop out the sensor and pop it into the smaller band.

After replacing my current band with the Kardia band (requires pushing the button just below the band and sliding the old band out then sliding the new one in) I was ready to go.

The Eternal  fiancée did not complain about the appearance of the band so I’m taking that to mean it passes the sufficiently stylish test. She did inquire as to different colors but it appears AliveCor only has one style and one color to choose from right now.

I have had problems with rashes developing with Apple’s rubbery band and switched to a different one but thus far the Kardia band is not causing wrist irritation.

Set UP

I didn’t encounter any directions in the box or online so I clicked on the Kardia app on the watch and the following distressing message appeared.

Prior to 11/30 Kardia Band only worked in certain countries in Europe so I suspected my AliveCor app needed to be updated.

I redownloaded the Kardia app from the Apple App Store , deleted it off my Watch and reinstalled it.

I was thrilled when the app opened up and gave me the following message

However, I was a little puzzled as I was not aware that setting up Smart Rhythm was a requirement to utilize the ECG recording aspect of Kardia Band. Since I have been granted a grandfathered Premium membership by AliveCor I knew that I would have access to Smart Rhythm and went through the process of entering my name and email into the Kardia app to get this started.

Alas, when the Watch Kardia app was accessed after this I continued to get the same screen. Clicking on “need help” revealed the following message:

Bluetooth was clearly on and several attempts to restart both the watch and the iPhone app did not advance the situation.

I sent out pleas for assistance to AliveCor.

At this point the Eternal Fiancee had awoken and we went to Sardella for a delightful brunch . I had this marvelous item:

Eggs Benedict Raviolo, Mortadella, Bread Ricotta, Egg Yolk, Brown Butter Hollandaise, Potatoes 15.
 Later on that day I returned to my Kardia Band iPhone and deinstalled, reinstalled , reloaded and restarted everything.
The First Recording
At this point it worked and I was able to obtain my first recording by pushing the record ECG button and holding my thumb on the sensor for 30 seconds.
I’ve made lots of recordings since then and they are good quality and have accurately recognized that I am in normal sinus rhythm.
The Smart Rhythm component has also been working. Here is a screen shot of today’s graph.
You’l notice that the Smart Rhythm AI gave me a warning sometime in the morning (which I missed) as it felt my rhythm was abnormal. I missed making the recording but am certain that I was not in afib.
Comparison of the Kardia Band recording (on the right) versus the separate Kardia device recording (on left)  shows that they are very similar in terms of the voltage or height of the p waves, QRS complexes and T waves. 
I felt a palpitation earlier and was able to quickly activate the Kardia Watch app and make a recording which revealed a PVC.
 In summary, after some difficulty getting the app to work I am very pleased with the ease of recording, the quality of the recording and the overall performance of Kardia Band. The difficulties I encountered might reflect an early adoption issue which may already be resolved. Please give me feedback on how the device set up worked for you.
I’ll be testing this out on patients with atrial fibrillation and report on how it works in various situations in future posts.
After more experience with the Smart Rhythm monitoring system which I think could be a fantastic breakthrough in personal health monitoring I’ll give a detailed analysis of that feature.
Everwatchingly Yours,
-ACP

AliveCor’s Kardia Band Is Now Available: Mobile ECG On Your Apple Watch

AliveCor has finally gotten approval from the FDA to release its Kardia Band in the United States.

The skeptical cardiologist is quite excited to get his hands (or wrist) on one and just gave AliveCor $199 to get it.

The device incorporates a mobile ECG sensor into a wrist band that works with either 42 or 38 mm Apple watches. I’ve written extensively about AliveCor’s previous mobile ECG product (here and here) which does a good job of recording a single lead ECG rhythm strip and identifying atrial fibrillation versus normal rhythm,

Hopefully, the Kardia Band will work as well as the earlier device in accurately detecting atrial fibrillation.

According to this brief video to make a recording you tap the watch screen then put your thumb on the sensor on the band.

The app can monitor your heart rate constantly and alerts you  to make a recording if it thinks you have an abnormal rhythm.

I was alerted to the release of Kardia by Larry Husten’s excellent Cardio Brief blog and in his post he indicates that the alert service , termed Smart Rhythm,  requires a subscription of $99 per year.:

AliveCor simultaneously announced the introduction of SmartRhythm, a program for the Apple Watch that monitors the watch’s heart rate and activity sensors and provides real-time alerts to users to capture an ECG with the Kardia Band. The program, according to an AliveCor spokesperson, “leverages sophisticated artificial intelligence to detect when a user’s heart rate and physical activity are out of sync, and prompts users to take an EKG in case it’s signaling possible abnormalities like AFib.”

The Kardia Band will sell for $199. This includes the ability to record unlimited ECGs and to email the readings to anyone. The SmartRhythm program will be part of the company’s KardiaGuard membership, which costs $99 a year. KardiaGuard stores ECG recordings in the cloud and provides monthly summary reports on ECGs and other readings taken.

AliveCor tells me my Kardia Band will be shipped in 1-2 days and I hope to be able to give my evaluation of it before Christmas.

Please note that I paid for the device myself in order to avoid any bias that could be introduced by receiving largesse from AliveCor.

Proarrhythmically Yours

-ACP

N.B. Larry Husten’s article includes some perspective and warnings from two cardiologist and can be read here.

Another article on the Kardia Band release suggests that the Smart Rhythm program at $99/ year is a requirement.

Perhaps, AliveCor’s David Albert can weigh in on whether the annual subscription is a requirement for making recordings or just allows the continuous monitoring aspect.

Blood Thinners (Oral Anticoagulants) For Atrial Fibrillation: Who Should Take Them and Which One To Take

The most serious  adverse consequence of having atrial fibrillation is stroke. Since we have safe and effective ways of preventing afib-related stroke with oral anticoagulant drugs (blood thinners), a major decision for the newly diagnosed patient with atrial fibrillation is “should I take a blood thinner?”

To answer this question the afibber should engage in a lengthy discussion with his/her health-care provider which results in a shared and informed  decision. Such discussion must cover your risk of stroke, the benefits of blood thinners in preventing stroke, the bleeding risks of blood thinners and the pros and cons of the five oral anticoagulants available to prevent stroke.

Estimating Your Risk of Stroke With Afib

The best way we have of estimating a patient’s risk of stroke if they have atrial fibrillation (AF) is by the CHA2DS2-VASc scale (which I like to call the Lip scale)

Stroke Risk EstimationThis scale take the factors we know that increase the risk of stroke and assigns 1 or 2 points. The acronym comes from the first letter of the factors that are known to increase risk as listed to the left.

Most of the factors get 1 point, but prior stroke (S) and age>75 (A) get 2 points.

We then add up your points and use another chart (or app) to calculate the risk of stroke per year.

CHA2 stroke riskYour risk of stroke is very low if you have zero risk factors; it gets progressively higher as you reach the maximum number of 9.

Treatment with an oral anticoagulant (OAC),  either warfarin, or one of the four novel anticoagulant agents (NOACS), is recommended when score is >/=2 corresponding to a  risk of stroke  above 1-2% per year.

These blood thinners have consistently been shown to lower your risk of stroke or systemic embolization (when a clot from the heart goes somewhere other than the brain) by almost 70%.

The higher the risk, the more the benefit of these blood thinners in preventing stroke.

Both European and American guidelines recommend using the CHA2DS2-VASc score for initial risk stratification. The European  guideline recommends OAC therapy for males with a CHA2DS2-VASc score ≥1 and for female patients with a score ≥2., whereas the American guideline recommends use of OAC if the CHA2DS2-VASc  score is ≥2 for men and women.

I’ve been using the CHA2DS2-VASc scale for several years in my afib patients. I try to review the patient’s risk of stroke and their risk of bleeding during every office visit, and decide whether they should be on or off an OAC.

Bleeding From Blood Thinners

All OACs cause increase bleeding. They don’t discriminate between bad clots that cause strokes and good clots that stop you from bleeding.

If you’re taking one you are more likely to have nose bleeds, bleeding into the intesitnal tract or urine and you will bleed longer when cut and more profusely if in an accident. In lower stroke risk patients, the bleeding risk of OAC of 1% per year may outweigh the benefits conferred by stroke reduction.

I wrote a post entitled “Why Does The TV Tell me Xarelto Is a Bad Drug” which points out that law suits against the makers of the newer OACs are frivolous and that these NOACs are likely more safe and effective than warfarin.

In recent years, four new drugs for reducing strokes in patients with atrial fibrillation which are much less influenced by diet and medications have gained approval from the FDA. These are generally referred to as “novel anticoagulants” reflecting their newness, different effects from warfarin or aspirin, and their blood thinning properties.  The first  (brand name Pradaxa) was released to much excitement and fanfare in October, 2010.  The press release for this approval read as follows:

PRADAXA, an oral direct thrombin inhibitor2 that was discovered and developed by Boehringer Ingelheim, is the first new oral anticoagulant approved in the U.S. in more than 50 years. As demonstrated in the RE-LY® trial, PRADAXA 150mg taken twice daily has been shown to significantly reduce stroke and systemic embolism by 35 percent beyond the reduction achieved with warfarin, the current standard of care for patients with non-valvular atrial fibrillation. PRADAXA 150mg taken twice daily significantly reduced both ischemic and hemorrhagic strokes compared to warfarin

What was very clear from the study with Pradaxa  and stated very clearly in all publications and patient and doctor  information sources was that just like warfarin, patients could have severe bleeding complications, sometimes fatal. Overall serious bleeding complications were about the same (the rate of major bleeding in patients Pradaxa  in the RE-LY trial was 3.1% versus 3.4% in the warfarin group) but Pradaxa had about 50% more bleeding from the gastrointestinal tract and warfarin about 50% more bleeding into the brain.

Another big difference between the novel anticoagulants and warfarin is that we have antidotes (Vitamin K, fresh frozen plasma) that can reverse the anticoagulation state rapidly for warfarin but until recently none for the newer drugs. (There is now available an antidote for Pradaxa).  This information also was made very clear to all doctors prescribing the medications in the package insert and educational talks. Despite this, in the major trials comparing these newer agents to warfarin, the newer agents were as safe or safer than warfarin.

The most feared bleeding complication on all OACs is bleeding into the head (intracranial hemorrhage). The risk of ICH is between 0.2 to 0.4 percent per year on warfarin. Studies show with the NOACs the risk is about half of the risk on warfarin.

Should You Take a NOAC or Warfarin?

Once the decision has been made to start a blood thinner, the next question is whether to take warfarin or a NOAC. Warfarin (brand name Coumadin) has been utilized since the 1950s  and prior to 2010 was  the only drug available for doctors to reduce clot formation in the heart and susbsequent strokes.. Warfarin is only effective and safe within a narrow window and its effects are strongly influenced by Vitamin K in the diet and most medications. Thus, frequent blood testing and adjustment in dosage is needed, and close monitoring of diet and changes in medications. Even with this close monitoring, serious and sometimes fatal bleeding occurs frequently with warfarin.

Here is a patient information sheet on warfarin which gives you an idea of issues you will need to be aware of when taking the drug. (WArfar patient handout)

If you do a Google search on warfarin you will quickly discover that it is used as a rat poison. Scientists isolate the chemical from  sweet clover that was causing cows to bleed and then developed a more potent form that they named warfarin in the 1940s. After developing blood tests that allowed the drug to be used safely  to dissolve clots it was approved for human use in the 1950s.

Warfarin or more potent variations on its chemical structure have been utilized as rat poison since the 1940s.

The rats are consuming much larger quantities of the blood thinner and are clearly not being monitored for blood thinness.

Some despicable sites peddling alternative or natural products such as this “Healthy Habits” site engage in fear-mongering over the warfarin/rat poison connection in order to promote totally unproven products. Healthy Habits indirectly suggests  that Nattokinase : is a safer, more effective natural alternative to warfarin” This remarkable enzyme has the ability to dissolve blood harmful clots involved in heart disease and strokes without upsetting normal healthy clotting.”

Such misinformation is dangerous and could lead to patients stopping a life-saving medication and suffering a stroke.

By the way, in this Xarelto (another NOAC competitor) ad, Screen Shot 2016-06-29 at 2.21.20 PMKevin Nealon says he chose Xarelto over warfarin because he wanted to eat salads. This is a common misconception and the makers of Xarelto should be ashamed for promulgating it.

I tell my patients it is fine to eat green, leafy vegetables while taking warfarin. The Vitamin K in the vegetables does influence the effectiveness of warfarin thinning blood but this is why we check the blood test to determine the appropriate dosage of warfarin for you and your personal dietary Vitamin K consumption , be it high or low.

Novel Oral Anticoagulant Drugs

The newer OACs, in contrast to warfarin do not require blood tests for monitoring of their efficacy because their levels are not significantly influenced by changes in diet or most medications.

In head to head studies versus warfarin four of these NOACs have demonstrated at least similar efficacy in preventing stroke and at most similar bleeding risk.

Due to their perceived advantages most new prescriptions for OACs are for NOACs. In contrast to 2014 American afib guidelines which don’t state a preference, the most recent European afib guidelines recommend choosing a NOAC over warfarin when initiating anticoagulant therapy in patients who are eligible for NOACs. (Ineligible patients include those with mitral stenosis, mechanical heart valves and end-stage renal disease.)

The ESC guidelines published in 2016, , make choosing a NOAC over warfarin a IA recommendation. This means there is a consensus that the treatment should be recommended (Class I recommendation) and that there is strong evidence from randomized controlled trials to support it (Level A.)

I have decided to primarily use Eliquis (apixaban) as my NOAC of choice based on my comparison of the different NOAC studies. If a patient’s insurance covers another NOAC better , making it cheaper then  I am happy to switch.

Because these four NOACs are new and brand name they are significantly more expensive than warfarin. Cost varies substantially based on type of insurance coverage and we can only determine how much a patient will pay for any given NOAC based on writing a prescription and having a pharmacy check out the cost.

I have found some patients paying nothing for their NOAC whereas some are paying several hundred dollars monthly. The more NOACs cost, the more likely the patient and I are to choose warfarin.

While waiting to determine if cost is going to be prohibitive I will typically provide the patient with samples of the NOAC chosen. The pharmaceutical companies making these NOACs are clearly making substantial profits off them and they are happy to provide lots of samples to doctors to influence the doctors to utilize their product.

NOACs are being extensively promoted both to physicians and directly to patients. Physicians have to be especially careful to make sure they are presenting a true summary of the relative risks and benefits of warfarin versus NOACs in light of these constant attempts to influence them.

Despite now having four NOACs with similar benefits and ease of use compared to warfarin, the cost of these agents doesn’t seem to have declined significantly from when the first NOAC came on the market. Personally, I would love to see Medicare step in and negotiate significantly lower costs for American senior citizens.

An abstract at the ACC meeting in March of 2017 suggested  a reduction in medical costs with NOACs despite their high costs. This was related to a lower rate of major bleeding complications: Xarelto cost $542 per patient compared with warfarin’s $500, or $42 more. Pradaxa, cost $367 to warfarin’s $452, saving $85.  Eliquis cost  $286 charge against warfarin’s $537 resulting in $251 in savings. Data were from from a study of U.S. Medicare patient records.

Aspirin May Not  Prevent Stroke In Afib

Many patients consider aspirin to be  a “blood thinner” that has some benefit in preventing clots and strokes in patients with afib. However,  aspirin is not considered a blood thinner or anticoagulant and is more properly  termed an anti-platelet agent.

I used to consider aspirin at doses of 120 to 200 mg daily provided some protection against stroke in afib and put afib patients on aspirin who were low risk for stroke or would not or could not take OACs.

More and more, however, experts are reaching the conclusion that the substantial bleeding complications from aspirin usage outweigh its very slight benefit in stroke prevention.

The most recent ESC guidelines, in fact, list aspirin therapy for stroke prevention in atrial fibrillation as IIIA. That means that overall it is felt to be harmful (III) with a high level of evidence (A.)

Bleeding risks for aspirin are similar to warfarin and Eliquis. Thus, patients should not consider aspirin as a safer alternative to prevent stroke in afib.

Finally, do not take any “natural” supplement that has been promoted as a blood thinner. These are neither safe nor effective. Remember that it took years of scientific investigation and careful testing in animals then humans before warfarin (the agent in sweet clover that caused cows to bleed ) was transformed into a safe and effective anticoagulant.

Antiemboligenically yours

-ACP

Is Chocolate Good For The Heart?

While in Paris recently,  allegedly researching the French Paradox, the skeptical cardiologist and his Eternal Fiancee’ participated in a Food Tour (Paris By Mouth).  Along with 2 other American couples, we were guided and educated by a Parisian food/wine expert as we wandered from one small shop to another in the St. Germain district of the Left Bank.

We collected the perfect Baguette Monge from Eric Kayser, delicious rillettes, terrine, and saucisson from Charcuterie Saint Germain, amazing cheese from Fromager Laurent Dubois, delightful  pastries from Un Dimanche a Paris, and unique and delicious chocolate from Patrick Roger.

The tour ended at La Cave du Senat wine shop, where we descended into a stone cellar and tasted all of the delicious foods while drinking wonderful wines.

The French Paradox refers to the fact that the French are among the world’s highest consumers of saturated fat, but have among the world’s lowest rates of cardiovascular disease. For those nutritional experts still obsessed with the dangers of all saturated fats, this poses a conundrum.

Cheese And The French Paradox

France consumes more cheese (27 kg per person per year) than any other country in the world (the US only consumes 16 kg per capita). Unlike Americans who have embraced low fat or skim versions of cheese, the French predominantly consume full fat cheese.

I wrote In Defense of Real Cheese  in 2014 and extolled the heart-healthy virtues of eating full fat , non factory-processed cheese.

Perhaps the French are protected against heart disease by their high consumption and love of real cheese ?

Chocolate And The French Paradox

Whereas cheese contains saturated fat and has been unfairly stigmatized as unhealthy, chocolate, similarly with high saturated fat content, seems to have been coronated as the king of food that is yummy but paradoxically is also heart healthy.

Could chocolate be the enigmatic protector of the hearts of the French?

Back on Boulevard Saint-Germain we entered the shop of Patrick Roger, who won the coveted Meilleur Ouvrier de France, in the craft of chocolate in 2000. The MOF is France’s way of recognizing the best artisans in various fields and occurs every 4 years. The standards are so high that in 2015 none of the 9 chocolatier competitors were felt to merit receiving the award.

The French clearly take their chocolate seriously but they don’t top the international charts at per capita consumption.

The Swiss consume 20 pounds of chocolate per year, whereas the French and US are tied for 9th, consuming 9.3 and 9.5 lbs. (Infographic from Forbes

 

 

Chocolate And The Heart

I’ve been meaning to write a post on chocolate and the heart since my encounter with high end chocolatiers in Paris and Bruges, and especially since May when there was much fanfare over a Danish study showing less atrial fbrillation in high chocolate consumers.

A NYTimes piece stimulated by the Danish study and entitled “Why Chocolate May Be Good For The Heart” typified the media headlines  and summarized the study thusly:

Scientists tracked diet and health in 55,502 men and women ages 50 to 64. They used a well-validated 192-item food-frequency questionnaire to determine chocolate consumption.

After controlling for total calorie intake, smoking, alcohol consumption, body mass index and other factors, they found that compared with people who ate no chocolate, those who had one to three one-ounce servings a month had a 10 percent reduced relative risk for atrial fibrillation, those who ate one serving a week had a 17 percent reduced risk, and those who ate two to six a week had a 20 percent reduced risk.

Previous large, well done observational studies also show that high chocolate consumption compared to no consumption is associated with a lower risk of cardiovascular disease.

Of course these being observational studies with only weak (but significant) associations, we cannot conclude that chocolate consumption actually  lowers the risk of developing afib or cardiovascular disease (causation.)

My favorite graph to hammer home this point is below and plots how much each country consumes in chocolate, versus the number of nobel laureates.

 

 

 

 

 

 

 

 

 

There is a good correlation here (Pearson’s (no relation unfortunately) correlation coefficient or r value) which is highly significant (p value <.0001). But does anyone seriously think a country can boost its Nobel Laureate production by promoting chocolate consumption?

The authors of the Danish afib trial, admit the possibility of residual or unmeasured confounding variables as a limitation in their discussion:

Although we had extensive data on diet, lifestyle and comorbidities, we cannot preclude the possibility of residual or unmeasured confounding. For instance, data were not available on renal disease and sleep apnoea. However, after adjusting for age, smoking status and other potential confounders, the association was somewhat attenuated but remained statistically significant.

Most chocolate authorities proclaim the health  benefits of dark chocolate over milk chocolate but in this Danish study:

We did not have information on the type of chocolate or cocoa concentration. However, most of the chocolate consumed in Denmark is milk chocolate. In the European Union, milk chocolate must contain a minimum of 30% cocoa solids and dark chocolate must contain a minimum of 43% cocoa solids; the corresponding proportions in the USA are 10% and 35%.16 Despite the fact that most of the chocolate consumed in our sample probably contained relatively low concentrations of the potentially protective ingredients, we still observed a robust statistically significant association, suggesting that our findings may underestimate the protective effects of dark chocolate.

Despite the fact that the participants in the Danish AFib study were likely mostly consuming  milk chocolate rather than dark chocolate,  the lead author of the study has been quoted as saying “dark chocolate with higher cocoa content is better… because it is the cocoa, not the milk and sugar, that provides the benefit.”

The Chocolate-Industrial -Research Complex

Julia Volluz, in a nicely written piece at Vox  entitled “Dark chocolate is now a health food. Here’s how that happened.” describes how “over the past 30 years, food companies like Nestlé, Mars, Barry Callebaut, and Hershey’s— among the world’s biggest producers of chocolate — have poured millions of dollars into scientific studies and research grants that support cocoa science.”

Here at Vox, we examined 100 Mars-funded health studies, and found they overwhelmingly drew glowing conclusions about cocoa and chocolate — promoting everything from chocolate’s heart health benefits to cocoa’s ability to fight disease. This research — and the media hype it inevitably attracts — has yielded a clear shift in the public perception of the products.

“Mars and [other chocolate companies] made a conscious decision to invest in science to transform the image of their product from a treat to a health food,” said New York University nutrition researcher Marion Nestle (no relation to the chocolate maker). “You can now sit there with your [chocolate bar] and say I’m getting my flavonoids.”

Flavonols and Blood Pressure

Dark chocolate and cocoa products are rich in chemical compounds called flavanols. Flavanols have attracted interest as they might help to reduce blood pressure, a known risk factor for cardiovascular disease. The blood pressure-lowering properties of flavanols are thought to be related to widening of the blood vessels, caused by nitric oxide.

The latest Cochrane Review on this topic commented on the poor quality of the studies involved:

Studies were short, mostly between two and12 weeks, with only one of 18 weeks. The studies involved 1804 mainly healthy adults. They provided participants with 30 to 1218 mg of flavanols (average of 670 mg) in 1.4 to 105 grams of cocoa products per day in the active intervention group. Seven of the studies were funded by companies with a commercial interest in their results, and the reported effect was slightly larger in these studies, indicating possible bias.

This graph from Volluz’s Vox article demonstrates how much chocolate you would need to consume to get the average amount of flavanols that participants in these studies received:

The Cochrane review felt there was

moderate-quality evidence that flavanol-rich chocolate and cocoa products cause a small (2 mmHg) blood pressure-lowering effect in mainly healthy adults in the short term.

Thus, for a very small drop in blood pressure you would have to make chocolate the main source of calories in your daily diet.

Consuming such large amounts of chocolate, even dark chocolate, would drastically increase your sugar consumption.

Further weakening any conclusions on the benefit of chocolate are that these are very short-term studies with markedly different baseline BPs, ages, and large variations in flavanol dosage.

Is Your Chocolate Produced By Slaves?

After reading the Danish AFib article, I purchased several bars of Tony’s Chocolonely chocolate that caught my eye at the Whole Foods checkout counter. The bars had interesting wrappers and on the inside of the wrapper I discovered that Tony’s Chocolonely’s claim to fame is that it is “slave-free.”

Per Wikipedia:

Tony’s Chocolonely is a Dutch confectionery company focused on producing and selling chocolate closely following fair trade practices, strongly opposing slavery and child labour by partnering with trading companies in Ghana and Ivory Coast to buy cocoa beans directly from the farmers, providing them with a fair price for their product and combating exploitation.

The slogan of the company is: “Crazy about chocolate, serious about people“.

I was previously unaware of the problem of child slavery and cocoa production. If you’d like to read more about it start here.

The Tony’s Chocoloney was so tasty I ended up consuming vast quantities of it at the end of the day and it disappeared rapidly. Currently the skeptical cardiologist’s house is chocolate free.

Should Chocolate Be Considered A Super Food or A Slave Food?

I can’t recommend chocolate to my patients as a treatment for high blood pressure or to reduce their risk of heart attack or stroke on the basis of the flimsy evidence available.

If you like chocolate, the evidence suggests no adverse effects of consuming it on a regular basis.

As far as flavanols obtained from cocoa and their benefits for cardiovascular disease, I eagerly awaiit the result of the ongoing Cocoa Supplement and Multivitamin Outcomes Study (COSMOS), a randomized trial looking at whether daily supplements of cocoa extract and/or a standard multivitamin reduces the risk of developing cardiovascular disease and cancer.

Patients and readers should recognize that there is an ongoing research/media campaign by Big Chocolate to convince them that chocolate is a SuperFood which can also be a dessert.

Flavanoidly Yours,

-ACP

What Is Behind The Significant Changes In AliveCor’s Kardia Mobile ECG App?

The Skeptical Cardiologist is a strong proponent of empowering patients with atrial fibrillation by utilizing personal cardiac rhythm devices such as Afib Alert or AliveCor’s Kardia.

I’ve written about my experiences with the initial versions of the Kardia mobile ECG device and the service it provides here and here.

I have been monitoring dozens of my afib patients using AliveCor’s Physician Dashboard.

Recently AliveCor changed fundamentally the way their app works such that for new users much of the functionality I described in my previous posts now requires subscribing to their Premium service which costs $9.99 per month or $99 per year.

What Has Changed With The Kardia App

The Kardia device which works with both iOs and Android smart
phones is unchanged and still generates a “medical-grade” single lead rhythm strips which appears within the Kardia app.

Screenshot from AliveCor’s website showing the Kardia recording device being utilized with the obtained  typical ECG recording displayed on the smartphone app.

 

 

The app still is reasonably accurate at identifying atrial fibrillation or normal heart rhythms and offers a fee-based service for interpretation of unclassified ECGs.

However, for new purchasers of Kardia,  the capability to access, email or print prior ECG recordings has gone away. Prior to March of this year, Kardia users could access prior ECG tracings which were stored in the cloud  by touching the “Journal” button on the app. These older tracings could be emailed and they were available through the cloud for a physician like myself to review at any time.

Now new Kardia purchasers will find that when they make an ECG recording they have the option to email a PDF of the ECG but once they hit the DONE button it is gone and is not stored anywhere.

For my patients purchasing after March, 2017 this means that unless they  purchase Kardia Premium service I will not be able to view their ECG recordings online.

An AliveCor account executive summarized for me the changes as follows:

We added a significant number of features over the past year and a half, and grandfathered all users on March 16th, 2017. New users now have the option to download and use Kardia for free, but the premium services are $9.99/mo or $99/year. Kardia Premium allows unlimited storage and history of their EKGs, summary reports with longitudinal data, blood pressure monitoring and tracking weight and medication.

Why Journal Functionality Is Important

If you purchased your AliveCor/Kardia device prior to March 16th, 2017 ago the journal  functionality still works. Let’s call such customers “Journal Grandfathered”.

This Journal functionality is important in a number of ways:

  1. My Journal Grandfathered patients can bring their phones with them during an office visit and we can review all of their ECG tracings.
  2. Journal gGandfathered Kardia users can email their old tracings to their physicians or to anyone they wish (even the skeptical cardiologist!). They can also print them out and save PDFs of the tracings.
  3. I  can view through my online physician account all of my Journal Grandfathered patients. This means any time a patient of mine makes a recording that is unclassified or suggests atrial fibrillation I can be notified and immediately view it online.

This fundamental change took place as AliveCor attempts to convince  purchasers of the Kardia device to use their Premium service.

Why AliveCor Changed The Kardia App Function

Dr. David Albert, inventor and  cardiologist and the founder of AliveCor was kind enough to talk with me about this change.

He indicates that of the 150,000 AliveCor users, 10,000 are now using the Kardia Premium service. About 20% of new users elect Kardia Premium.

Prior to the change all AliveCor users had their old ECG recordings stored in the cloud in a HIPPA compliant fashion. This free service was costing AliveCor quite a bit and the company felt it was best to switch to a subscription service to provide this secure cloud storage.

With the change to the (relatively inexpensive)  subscription service, patients will get additional features. As the AliveCor account executive described:

Kardia Premium allows unlimited storage and history of their EKGs, summary reports with longitudinal data, blood pressure monitoring and tracking weight and medication.

 

 

I’ve looked at the Premium service and it seems quite useful when combined with a connected physician utilizing Kardia Pro.  I’ll evaluate the Premium service and the physician Kardia Pro service  further and write a full post on its features in the near future.

If you are not grandfathered and want to stick with the Basic Kardia service you still have an immensely useful and  inexpensive device which allows personal detection of your cardiac rhythm. Just remember to email yourself the ECG recording you just made before you hit DONE.

Nonarrhythmically Yours,

-ACP

Why Did I Go Into Atrial Fibrillation?

The skeptical cardiologist is asked this  question or  variations of it (such as  what caused me to go out of rhythm?) on a daily basis.

Most patients would like to have a reason for why their atria suddenly decided to fibrillate.  It’s understandable. If they could identify the reason perhaps they could stop it from happening again.

There are two variations on this question:

For the patient who has just been diagnosed with afib the question is really “what is the underlying reason for me developing this condition?”

For the patient who has had afib for a while and it comes and goes seemingly randomly the question is “what caused the afib at this time? i.e. what triggers my episodes?”

For most patients, there is no straighforward and simple answer to either one of these questions

The Underlying Cause of Atrial Fibrillation

My stock response to this first question goes like this:

“Atrial fibrillation is associated with getting older and having high blood pressure. 10 % of individual >/= 80 years have atrial fibrillation. 90% of patients with afib have hypertension.

Aging and hypertension may increase scarring or damage in the left atrium or pulmonary veins that drain into the left atrium setting up abnormal electrical signals.

There are some specific things that cause afib and we will be doing a complete history and physical and some testing to check for the most common. We’ll check you for thyroid or electrolyte abnormalities and we will do an echocardiogram to look for any structural problems with your heart.

If we do find a treatable cause such as hyperthyroidism or a cardiac valve problem we will fix that and the afib may go away, however chances are we won’t find a specific reason why you developed atrial fibrillation.

Finally, and possibly most importantly, let’s take a close look at your lifestyle. Are you overweight? If so, losing 10% of your body weight will substantially lower your risk of recurrent atrial fibrillation. Let’s get you exercising regularly and eating a healthy diet, Make sure your sleep is optimized and your stress minimized.”

If you’d like a more sophisticated look into what causes afib take a look at this graphic from a recent paper.

Current theory has it that factors that we know are associated with atrial fibrillation  including obesity, hypertension and sleep apnea cause atrial structural abnormalities or remodeling which then create various atrial electrical abnormalities.

 

Exhaustive List of Causes

If you’d like an exhaustive list of factors associated with atrial fibrillation, you can memorize the acronym P.I.R.A.T.E.S. which is sometimes used by medical students to remember the causes of atrial fibrillation which include:

  • Pulmonary disease (COPD, PE)/Phaeochromocytoma
  • Ischemia (ACS)
  • Rheumatic heart disease (mitral stenosis)
  • Anemia (high output failure/tachycardia)/Atrial myxoma/Acid-base disturbance
  • Thyrotoxicosis (tachycardia)
  • Ethanol/Endocarditis/Electrolyte disturbance (hypokalaemia, hypomagnesaemia)/Elevated BP
  • Sepsis/Sick Sinus Syndrome/Sympathomimetics (Drugs)

And here’s a cute  mnemonic from the Family Practice Notebook using ATRIAL FIB itself (although you have to use the ph of pheochromocytoma to make the f of fib)

  1. Alcohol Abuse
  2. Thyroid Disease
  3. Rheumatic Heart Disease
  4. Ischemic Heart Disease
  5. Atrial Myxoma
  6. Lung (Pulmonary Embolism, Emphysema)
  7. Pheochromocytoma
  8. Idiopathic
  9. Blood Pressure (Hypertension)

Both of these mnemonics are a little outdated. For example, rheumatic mitral stenosis is quite rare as a cause of afib in the US but  degenerative and functional mitral regurgitation is a common cause.

Ischemic heart disease (aka coronary heart disease) isn’t felt to cause atrial fibrillation unless it results in a myocardial infarction and subsequent heart failure. Way too many cardiac catheterizations are performed on patients who present with atrial fibrillation by doctors who don’t know this.

Congenital heart defects (not mentioned in either mnemonic) especially atrial septal defects often are associated with afib

There may be case reports of pheochromocytoma (a catecholamine-secreting neuroendocrine tumor) causing afib but they are few and far between.

Finally, genetics clearly play a role in the younger patient with afib without any known risk factors. One of my patients and his twin brother both developed symptomatic afib in their 40s.

In The Chronic Afibber What Triggers An Episode?

Alas, for most afibbers we won’t identify specific reasons why you go in and out of afib although there are some triggers you should definitely avoid such as excessive alcohol.

Some of the “causes” listed in the mnemonic are acute triggers of afib episodes.

For example low potassium or magnesium (typically induced by diuretics, diarrhea or vomiting) can bring on episodes .(See my discussion on potassium and PVCS here-much of it is relevant to afib.)

And I  have definitely seen patients go  into atrial fibrillation who have acute pulmonary problems such as pneumonia, pulmonary embolism or exacerbation of COPD.  In these cases, it is felt that the lung process raises pressure in the pulmonary arteries thereby  putting strain on the right heart leading to higher right atrial pressures.

Sleep apnea is associated with afib and I have had a few cases where after identifying that a patient’s  afib always began during sleep we were able to substantially lower episodes by treatment of sleep apnea.

Pericarditis with inflammation adjacent to the left atrium not uncommonly causes  afib. This is the likely mechanism for the afib that occurs frequently after cardiac surgery. Since pericarditis may never recur (especially in the cardiac surgery patient) we think the risk of afib recurring is low in these patients.

Anything that raises stress and stimulates the sympathomimetic nervous system can be a trigger. For example, a young and otherwise healthy patient of mine went into afib after encountering a car in flames along the side of the road. We found that beta-blockers (which block the sympathetic nervous system) helped prevent her episodes.

Some patients have odd but reproducible triggers. One of my patients routinely went into afib when he ate ice cream. I had a simple , very effective treatment plan for him.

Caffeine and Chocolate

Many afibbers have been told to avoid caffeine but a recent study of 34,000 women found that there was no increased risk of afib with increasing caffeine content and no sign that any of the individual contributors to caffeine in the diet (coffee, tea, cola, and chocolate) were more likely to cause afib.

Higher chocolate consumption, in fact, has recently been linked to a lower rate of afib. An observational  study of 55 thousand Danish men and women found that those who consumed 2 to 6 servings per week of 1 oz (30 grams) of chocolate had a 20% lower rate of clinically apparent afib.

Alcohol and Atrial Fibrillation

Binge drinking has long been known to cause acute atrial fibrillation.

However, it appears that even light to moderate chronic alcohol consumption increases the risk of going into atrial fibrillation.

This graphic from an excellent recent review of the topic gives the potential mechanisms:

The review concludes that although light to moderate alcohol consumption lowers your risk of dying, any alcohol consumption increases your risk of afib.

This graph shows the relationship between dying from heart disease (red line) and risk of going into afib (blue line) and amount of alcohol consumed.

Looking at the 15 drinks per week point on the x-axis (about 2 drinks per day) we see that your CV mortality is reduced by 20% whereas your risk of afib has increased by 20%.

A better point on the x-axis is 7 (1 drink per day) which has a 25% lower CV mortality but only a 10% higher risk of afib.

Whatever caused you to go into afib the good news is that with lifestyle changes and the care of a good cardiologist chances are excellent that you can live a normal, happy, healthy , long and active life.

Etiologically Yours,

ACP

 

Is September Really National Atrial Fibrillation Awareness Month (And Why Does It Matter?)

The skeptical cardiologist received an email from a woman telling him that September is atrial fibrillation awareness month and offering me the free use of an infographic given that I

“care deeply about helping people living with AF.”

Well, I do care about deeply about people living with atrial fibrillation and pretty much all cardiac diseases  (except perhaps Schuckenbuss syndrome.)

That’s the major reason I write this blog. I’ve written a lot about Afib and have a lot more i want to write (I really want to write about antiarrhythmic drugs, i.e. drugs that maintain you in normal sinus rhythm.)

But I don’t find it particularly helpful to assign a disease to a month or a day so my posts on atrial fibrillation come out randomly dependent on the mysterious machinations of my messy mind.

It turns out that September, 2009 was declared National Atrial Fibrillation Awareness Month (NAFAM) by Senate Resolution 262 although Stop Afib.org wants us to believe September is eternally NAFAM.

However, the email prompted me to better organize my atrial fibrillation and stroke page (now containing all that I have written on the subjects) which I have copied below.

Posts on Diagnosing Atrial fibrillation

Take your pulse and prevent a stroke

TIAs and silent atrial fibrillation. Sometimes strokes present in unusual ways, like the inability to differentiated a spade from a diamond when playing bridge and afib is often the cause.

Estimating Stroke Risk in Patients With Atrial Fibrillation You can estimate your stroke risk using an app that utilizes the CHAD2DS2-VASc score. I prefer to call the Lip score.

Posts About Using Personal Devices To Diagnose Atrial Fibrillation

Two That Work Reasonably Well

AliveCor

Using a Smart Phone Device and App To Monitor Your Pulse for Atrial Fibrillation (AliveCor)

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

AliveCor Successes and Failures.

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

AfibAlert

How Well Does The AfibAlert Remote Hand-Held Automatic ECG Device Work For Detection of Atrial Fibrillation?

AfibAlert Versus AliveCor/Kardia: Which Mobile ECG Device Is Best At Accurately Identifying Atrial Fibrillation?

And One of Several Devices To Avoid: AF Detect

Do NOT Rely on AF Detect Smartphone App To Diagnose Atrial fibrillation

Posts About Treatment Of Atrial Fibrillation

        Lifestyle Changes

How Obesity Causes Atrial Fibrillation in FatSheep and How Losing Weight helps prevent afib from coming back.

Drug Therapy: Rate Control and Anticoagulation

Foxglove Equipoise. When William Withering began treating patients suffering from dropsy in 1775 with various preparations of the foxglove plant he wasn’t sure if he would help or hurt them. After 240 years of treatment, we are still unsure if the drug obtained from foxglove is useful.

Should Digoxin Still Be Used in Atrial Fibrillation? Recent studies suggest that we should not.

Why Does the TV Tell Me Xarelto Is A BAD Drug? Anticoagulant drugs that prevent the bad clots that cause stroke also increase bleeding risk. A bleeding complication is not a valid reason to sue the manufacturer.  The lawsuit are strictly a money-making tactic for sleazy lawyers.

Cardioversion and Ablation

Cardioversion: How Many Times Can You Shock The Heart?

Ablation: Cautionary Words From Dr. John Mandrola and The Wisdom of a Team Approach

Miscellaneous Topics

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

Infographics

Are infographics really helpful? Someone should do a study on that. Perhaps we could use the money we spend on infographics in atrial fibrillation to research whether the left atrial appendage should be excised at the drop of a hat.

Here’s the infographic (because everyone loves an infographic!)

The first part lays out the problem of AF with patriotic bunting.

The second part uses the annoying numerical infographic approach.

 

 

 

 

 

 

 

The third part explains why I got the email. A product is being promoted. The woman who sent me the email works for MyTherapyApp.

 

 

 

Eagerly Awaiting Schuckenbuss Syndrome Day,

-ACP

 

 

 

AliveCor (Kardia) Has A Premature Beat Problem: How PVCs and PACs Confuse The Mobile ECG Device

The skeptical cardiologist has many patients who are successfully using their AliveCor/Kardia devices to monitor for episodes of atrial fibrillation (afib).

However, a significant number of patients who have had atrial fibrillation also have premature beats. Sometimes patients feel these premature beats as a skipping or irregularity of the heart beat. Such palpitations  can mimic the feeling patients get when they go into atrial fibrillation.

The ideal personal ECG monitor, therefore,  would be able to reliably differentiate afib from premature beats for such patients.

Premature Beats: PVCs and PACs

I’ve discussed premature ventricular contractions (PVCs) here and here.  Premature beats can also originate from the upper chambers of the heart or atria.

Such  premature atrial contractions (PACs) have generally been considered benign in the past but a recent study showed that frequent (>30 s per hour) PACs  or runs of >20 PACs in a row were associated with a doubling of stroke risk.

For patients who experience either PVCs or  PACs the AliveCor device is frequently inaccurate.

PACs Misdiagnosed As Atrial Fibrillation

Here is a panel of recordings made by a patient of mine who has had documented episodes of atrial flutter in the past and who monitors his heart rhythm with Alivecor regularly:

Of the ten recordings , four were identified as “possible atrial fibrillation.”

Unfortunately only one of the four “possible atrial fibrillation” recordings has any atrial fibrillation: this one has 7 beats of afib initially then changes to normal sinus rhythm (NSR).

The other 3 recordings identified by AliveCor as afib are actually normal sinus rhythm with premature beats.

The first 3 beats are NSR. Fourth beat is a premature beat

In addition, frequently for this patient AliveCor yields an “Unclassified” reading for NSR with PACs as in this ECG:

PVCs Misread As Atrial Fibrillation

I wrote about the first patient I identified in my office who had frequent PVCs which were misdiagnosed by AliveCor as afib here.

Since then, I’ve come across a handful of similar misdiagnoses.

One of my patients began experiences period palpitations 5 years after an ablation for atrial fibrillation. He obtained an AliveCor device to rec  ord his rhythm during episodes.

For this patient,, the AliveCor frequently diagnoses “possible atrial fibrillation” but  all of his episodes turn out not to be afib. In some cases he is having isolated PVCs:

The first 3 beats in the lower strip are NSR. The fourth beat (purpose circle) is a PVC. AliveCor interpreted this as afib

At other times he has periods of atrial bigeminy  which are also called afib by AliveCor. In this tracing he has atrial bigeminy and a PVC.

 

 

PVCs Read As Normal

Premature beats sometimes are interpreted by AliveCor as normal. A reader sent me a series of  recordings he had made when feeling his typical palpitations. all of which were called normal. Indeed, all of them but one showed NSR. However on the one below the cause of his palpitations can be seen: PVCs.

The NSR beats (blue arrows) followed at times by PVCs (red arrows))

I obtained the “Normal”  tracing below from a patient in my office with a biventricular pacemaker and frequent PVCs who had no symptoms.

Paced beats (blue arrows) PVCs (red arrows)

PVCs Read As Unclassified 

A woman who had undergone an ablation procedure to eliminate her very frequent PVCS began utilizing AliveCor to try to determine if she was having recurrent symptomatic PVCs. She became quite frustrated because AliveCor kept reading her heart rate at 42 BPM and giving her an unclassified reading.

AliveCor is always going to call rhythms (other than afib) unclassified when it counts a  heart rate less than 50 BPM or greater than 100 BPM.

In this patient’s case, every other beat was a PVC (red circles). Her PVCs are sufficiently early and with low voltage so the AliveCor algorithm cannot differentiate them from T Waves and only counts the normal sinus beats toward heart rate.

Accurate AliveCor Readings

I should point out that many of my patients get a very reliable assessment from their devices. These tracings from a woman with paroxysmal atrial fibrillation  are typical: all the Normal readings are truly normal and all the atrial fibrillation readings are truly atrial fibrillation with heart rates  above 100.

AliveCor’s Official Position on Premature Beats

The AliveCor manual states

The Normal Detector in the AliveECG app notifies you when a recording is “normal”.  This means that the heart rate is between 50 and 100 beats per minute, there are no or very few abnormal beats, and the shape, timing and duration of each beat is considered normal.

What qualifies as “very few” abnormal beats is not clear. The manual goes on to state that the AliveCor normal detector has been designed to be conservative with what it detects as normal.

What is clear is that premature beats  significantly confuse the AliveCor algorithm. Both PVCs and PACs can create a false positive diagnosis of atrial fibrillation when it is not present.

Consequently, if you have afib and premature beats you cannot be entirely confident that a reading of afib is truly afib. Strongly consider having the tracing reviewed by a cardiologist before concluding that you had afib.

On the other hand if you are experiencing palpitations and make a recording with Alivecor that comes back as normal do not assume that your heart rhythm was totally normal. While highly unlikely to be afib, your palpitations could still be due to PACs or PVCs.

If a patient of mine has an abnormal or questionable AliveCor recording it is currently a very simple process for me to review the recording online  through my AliveCor doctor dashboard. The recordings can also be emailed to me.

However, Kardia appears to be trying to move new AliveCor purchasers to a subscription or Premium service. In addition, Kardia keep giving me messages that “the doctor dashboard is going away.”

Coralively Yours,

-ACP

AfibAlert Versus AliveCor/Kardia: Which Mobile ECG Device Is Best At Accurately Identifying Atrial Fibrillation?

The skeptical cardiologist has been testing the comparative accuracy of two hand-held mobile ECG devices in his office over the last month. I’ve written extensively about my experience with the AliveCor/Kardia (ACK) device here and here. Most recently I described my experience with the Afib Alert (AA) device here.

Over several days I had my office patients utilize both devices to record their cardiac rhythm and I compared the device diagnosis to the patient’s true cardiac rhythm.

Normal/Normal

In 14 patients both devices correctly identified normal sinus rhythm. AFA does this by displaying a green check mark , ACK by displaying the actual recording on a smartphone screen along with the word Normal.

The AFA ECG can subsequently uploaded via USB connection to a PC and reviewed in PDF format. The ACK PDF can be viewed instantaneously and saved or emailed as PDF.

 

Normal by AFA/Unreadable or Unclassified by AliveCor

In 5 patients in normal rhythm (NSR) , AFA correctly identified the rhythm but ACK was either unreadable (3) or unclassified (2). In the not infrequent case of a poor ACK tracing I will spend extra time adjusting the patient’s hand position on the electrodes or stabilizing the hands. With AFA this is rarely necessary.

In this 70 year old man the AFA device recording was very good and the device immediately identified the rhythm as normal.

Chaput AFA SR

ACK recording was good quality but its algorithm could not classify the rhythm.

GC Unclassified

A 68 year old man who had had bypass surgery and aortic valve replacement had a very good quality AFA recording with correct classification as NSRChaput AFA SR

AliveCor/Kardia recordings on the same patient despite considerable and prolonged efforts to improve the recording were poor and were classified as “unreadable”

Scott AC unreadable
Alivecor tracing shows wildly varying baseline with poor definition of p wave

 

False Positives

There were 3 cases were AFA diagnosed atrial fibrillation (AF) and the rhythm was not AF. These are considered false positives and can lead to unncessary concern when the device is being used by patients at home. In 2 of these ACK was unreadable or unclassified and in one ACK also diagnosed AF.

A 90 year old woman with right bundle branch block (RBBBin NSR was classified by AFA as being in AF.

VA AFA read as AF
Slight irregularity of rhythm combined with a wider than normal QRS from right bundle branch block and poor recording of p waves likely caused AFA to call this afib
VA unclassified RBBB
AliveCor tracing calls this unclassified. The algorithm does not attempt to classify patients like this with widened QRS complexes due to bundle branch block.

The ACK algorithm is clearly more conservative than AA. The ACK manual states:

If you have been diagnosed with a condition that affects the shape of your EKG (e.g., intraventricular conduction delay, left or right bundle branch block,Wolff-Parkinson-White Syndrome, etc.), experience a large number of premature ventricular or atrial contractions (PVC and PAC), are experiencing an arrhythmia, or took a poor quality recording it is unlikely that you will be notified that your EKG is normal.

 

One man’s rhythm confounded both AFA and AC. This gentleman has had atrial flutter in the past and records at home his rhythm daily using his own AliveCor device which he uses in conjunction with an iPad.IMG_8399.jpg

During our office visits we review the recordings he has made. He was quite bothered by the fact that he had several that were identified by Alivecor as AF but in fact were normal.

Screen Shot 2017-05-06 at 11.48.47 AM
These are recordings Lawrence made at home that i can pull up on my computer. He makes a daily recording which he repeats if he is diagnosed with atrial fibrillation. In the two cases above of AF a repeat measurement was read as normal. Of the two cases which were unclassified , one was normal with APCs and the other was actually atrial flutter

A recording he made on May 2nd at 845 pm was read as unclassified but with a heart rate of 149 BPM. The rhythm is actually atrial flutter with 2:1 block.

Screen Shot 2017-05-06 at 11.47.37 AM

Sure enough, when I recorded his rhythm with ACK although NSR (with APCS) it was read as unclassified

Screen Shot 2017-05-06 at 11.49.49 AM

AFA classified Lawrence’s rhythm as AF when it was in fact normal sinus with APCs.

AFA Mcgill AF

 

 

One patient a 50 year old woman who has a chronic sinus tachycardia and typically has a heart rate in the 130s, both devices failed.

We could have anticipated that AC would make her unclassified due to a HR over 100 worse than unclassified the tracing obtained on her by AC (on the right)was terrible and unreadable until the last few seconds. On the other hand the AFA tracing was rock solid throughout and clearly shows p waves and a regular tachycardia. For unclear reasons, however the AFA device diagnosed this as AF.

 

 

Accuracy in Patients In Atrial Fibrillation

In 2/4 patients with AF, both devices correctly classified the rhythm..

In one patient AFA correctly diagnosed AF whereas ACK called it unclassified.

This patient was in afib with HR over 100. AFA correctly identified it whereas ACK called in unclassified. The AC was noisy in the beginning but towards the end one can clearly diagnose AFScreen Shot 2017-05-06 at 8.39.06 AMScreen Shot 2017-05-06 at 8.11.53 AM

In one 90 year old man AFA could not make the diagnosis (yellow)

Screen Shot 2017-05-06 at 11.35.40 AM

ACK correctly identified the rhythm as AF

Screen Shot 2017-05-06 at 11.37.51 AM

One patient who I had recently cardioverted from AF was the only false positive ACK. AliveCor tracing is poor quality and was called AF whereas AFA correctly identified NSR>

Screen Shot 2017-05-06 at 8.42.46 AMScreen Shot 2017-05-06 at 8.42.26 AM

 

 

Overall Accuracy

The sensitivity of both devices for detecting atrial fibrillation was 75%.

The specificity of AFA was 86% and that of ACK was 88%.

ACK was unreadable or unclassified 5/26 times or 19% of the time.

 

The sensitivity and specificity I’m reporting is less than reported in other studies but I think it represents more real world experience with these types of devices.

Summary

In a head to head comparison of AFA and ACK mobile ECG devices I found

-Recordings using AfibAlert are usually superior in quality to AliveCor tracings with a minimum of need for adjustment of hand position and instruction.

-This superiority of ease of use and quality mean almost all AfibAlert tracings are interpreted whereas 19% of AliveCor tracings are either unclassified or unreadable.

-Sensitivity is similar. Both devices are highly likely to properly detect and identify atrial fibrillation when it occurs.

-AliveCor specificity is superior to AfibAlert. This means less cases that are not AF will be classified as AF by AliveCor compared to AfibAlert. This is due to a more conservative algorithm in AliveCor which rejects wide QRS complexes, frequent extra-systoles.

Both companies are actively tweaking their algorithms and software to improve real world accuracy and improve user experience but what I report reflects what a patient at home or a physician in office can reasonably expect from these devices right now.

-ACP

QardioArm: Stylish, Accurate and Portable. Is It the iPhone of Home Blood Pressure Monitors?

The skeptical cardiologist frequently has his hypertensive patients check their BPs at home and report the values to him.

An easy, accurate and efficient way to record BPs at home, and transmit to the doctor, is my Holy Grail for management of hypertension; QardioArm offers to improve on this process compared to more conventional home BP cuffs.

I recently bought a QardioArm for my father and tested one myself over the last month, and herein are my findings. I compared it closely to my prior “go to”  BP device, the Omron 10 (which I recommended as a Christmas gift here).

Appearance

The QardioArm looks like and is packaged like an Apple product. The box containing the device is esthetically pleasing, and can serve as an excellent storage and transportation mechanism. The case closes magnetically and has a pocket, within which resides the manual.

 

Upon removing the QardioArm, one is struck by how compact, sleek and cool it looks. This is not your father’s BP cuff. There are no wires or tubes coming off it, and the cuff wraps around a red (white, blue or gold) plastic rectangular cuboid.

The cuff/cuboid is small enough to easily fit in a purse or satchel, facilitating portability.

Ease of Use

Once you understand how the device works it is a breeze to use.  However, if you are inclined, like me, to skip reading the instruction manual, you run the risk of being incredibly frustrated.

First, you must download the free Qardio App to your smartphone, create a user login, register and create your personal account. If you don’t have a smartphone or tablet or don’t use the internet, this cuff if not for you. For me, this was a simple, quick process.

After setting up the Qardio App, you pair the QardioArm with the App. This requires the QardioArm be on and Blue Tooth be enabled on your smartphone.

An example of the profoundly negative review individuals give the device when they have not figured out the on/off process. This one on Consumer Reports

You might think that turning on the QardioArm, and knowing it is on,
would be an incredibly easy and obvious process: it is not (unless you pay close attention to the instructions). If you read reviews of Qardioarm on Consumer Reports or Amazon, you will encounter many very unhappy users. This is primarily because some folks could not get it to turn on.


Here are my detailed instructions for turning it on:

  1. There is a small magnet inside the cuff.
  2. The device turns itself on when you unwrap the cuff and it turns off when you wrap the cuff back up. (I am not good at wrapping things up properly and ran into issues initially because of this). When you wrap the cuff up properly you can feel the magnet locking into place and thus turning the device off.
  3. When the device is on there is no light to indicate it is on. A green light flashes on the side when it turns on, but then goes out. Many user reviews indicate frustration with this and often they end up trying to change the batteries, believing that the device is dead. I went through this same thought process initially.
  4. The device turns off “after a few minutes” if not used. You won’t know if it is on or off. If it doesn’t respond when you trigger it from the App, you must carefully rewrap the cuff and then unwrap it. If you don’t trigger the device properly with the magnet, it won’t wake up.

The QardioArm encircling the beautiful arm of the eternal fiancee’ of the skeptical cardiologist. Note: when the cuff is wrapped around my unattractive arm, it fastens properly and does not hang down.

Now that you know how to turn the device on and have paired it with your Cardio App, put the cuff over your upper arm with the cuboid over the inner aspect of your arm,
hit the big green START button and sit back while the cuff is magically inflated and an oscillometric measurement of your blood pressure performed.

 

 

The blood pressure is displayed on the app instantaneously along with pulse. If the device detects irregularity of the pulse (a possible but not reliable sign of atrial fibrillation or other abnormal heart rhythms), it display an “irregular heart beat” warning.

You can have the QardioArm take 3 BPs, a variable amount of time apart, and average the readings.

BP and pulse data can be viewed in tabular or graphic formats and  can be synched with the Apple Health App:

 

Accuracy

I found the QardioArm BP measurements to be very accurate. My medical assistant, Jenny, recorded our patient’s BPs using the “gold-standard” manual technique, and with QardioArm (consecutively and in the same arm), and there was excellent agreement. In one man with a very large arm, she could not record a BP (QardioArm’s cuff fits the arm of most people, and is appropriate for use by adults with an upper arm size between 22 and 37 cm (8.7 and 14.6 inches).  If your upper arm is larger than that, this device is not for you.  In one patient who was in atrial fibrillation, the device properly recorded an “irregular heart beat.”

From the Qardio website:

QardioArm is a highly accurate blood pressure monitor and has undergone independent, formal clinical validation according to ANSI/AAMI/ISO 81060-1:2007, ANSI/AAMI/ISO 81060-2:2009, ANSI/AAMI/IEC 80601-2-30:2009, as well as British Standard EN 1060-4:2004.

QardioArm is a regulated medical device: FDA cleared, European CE marked and Canadian CE marked.

It measures blood pressure with a resolution of 1 mmHg and pulse with 1 beat/min.

The accuracy is +/- 3 mmHg or 2% of readout value for blood pressure, and +/- 5% of readout value for pulse.

Comparison To Omron 10

I spent time evaluating the accuracy of QardioArm because a few online reviewers suggest that it is highly inaccurate for them and Consumer Reports gives it a “poor” rating for accuracy.

Consumer Reports gave the QardioArm an astonishingly low score giving it lower marks than the Omron for Convenience, Accuracy and Comfort. It gave the QardioArm a Poor mark for accuracy. No details of their measurement data are available on the site.

I compared it to the Omron 10 (Consumer Reports highest-rated BP device), and found close agreement between the two.

Simultaneous BP using Omron (above) and QardioArm (left)


I took my own BP with the QardioArm on the left arm and the Omron 10 on the right arm. Multiple simultaneous measurements showed less than 3 mmHg difference in systolic blood pressure between the two.

Unlike Consumer Reports, I found QardioArm superior to the Omron 10 in several areas:

  1. QardioArm is faster. It took 30 seconds to complete a BP measurement, compared to 50 seconds for the Omron 10.
  2. BPs are immediately available on my iPhone with QardioArm, whereas a separate Bluetooth synching process is required for the Omron App. This process never works well for me, as the Omron fails to transmit measurements reliably.
  3. It is amazingly easy to transmit BPs via email to your doctor (or friends if so inclined).

Support

I found the QardioArm website to be very informative and helpful. The manual that comes with the device is very complete and you should definitely read it before using the device. I did not need telephone or email support services, so I can’t comment on those.

Overall Rating and a Caveat

Despite an initial frustration with QardioArm, I ended up really liking this device a lot. This sounds a little silly but the QardioArm improved the esthetic experience of home BP monitoring for me. Because it is compact, sleek and attractive, patients may be more likely to utilize it on a regular basis. In particular, I see it as something that you would be much more inclined to take with you for BP monitoring at work or on vacation.

I will be recommending  this to my tech-savvy, style-conscious patients who require home BP monitoring. Previously, this type of patient would bring in their smartphone and show me the accumulated data from their BP readings. With a QardioArm, they can easily email my office the data and we can have it scanned into their record.

My final caveat: the QardioArm I gave my father for his 91st birthday does not work on his arm. It works without a problem on the arms of his friends and relatives. I have no idea why, but fortunately QardioArm honored their 30 day 100% money-back no questions asked guarantee. I’ve asked him to give me his nonagenarian perspective on the QardioArm experience so I can share it in a future post.


Quriously Yours,

-ACP