Ƶ

Skeptical Cardiologist: Do Mobile Heart-Monitoring Devices Work?

— Anthony Pearson, MD, explores the pros and cons of these consumer devices

Ƶ MedicalToday
image

AliveCor in March 2017 as a cloud-based software platform that allows physicians to monitor patients who use the Kardia mobile ECG device.

I have been utilizing the Kardia mobile ECG device since 2013 with many of my atrial fibrillation (Afib) patients and have found it be very useful as a personal intermittent long-term cardiac monitor. (See and )

I signed up for the Kardia Pro service about 3 months ago, and all of my patients who purchased Kardia devices prior to March 2017 were migrated automatically to Kardia Pro by AliveCor.

New users who acquire a Kardia device must sign up for the Kardia Pro service at $15 per month to connect with a physician.

I think this is money well spent, and I'll demonstrate how the service works with a few examples.

Monitoring AF Patients

I saw a 68-year-old man with persistent Afib that was first diagnosed at the time of pneumonia in late 2017.

He underwent a cardioversion after recovering from the pneumonia but quickly reverted back to Afib. His prior cardiologist offered him the option of repeat cardioversion and long-term flecainide (Tambocor) therapy for maintenance of normal sinus rhythm (NSR), but he declined.

When I saw him for the first time in the office a month ago, I listened to his heart and, to my surprise, noted a regular rhythm: An AliveCor recording in the office confirmed he was in NSR. The patient had been unaware of when he was in or out of rhythm.

We discussed methods for monitoring his rhythm at this point, which included a 24-hour Holter monitor, a 7- to 14-day Long Term Monitor, a Cardiac Event Monitor, and a Mobile Cardiac Outpatient Telemetry device. These devices are helpful and, although expensive, are often covered by insurance. They require wearing electrodes or a patch continuously and the results are not immediately available.

I also offered him the option of monitoring his Afib using a Kardia device with the recordings connected to me by Kardia Pro.

He purchased the device on his own for $99, downloaded the app for his smartphone, and began making recordings.

I enrolled him in my Kardia Pro account, and he received an email invitation with a code that he entered that connected his account with mine, allowing me to view all of his recordings as they were made.

When I log into my Kardia Pro account, I can now view a graphic display of the recordings he has made with color coding of whether they were considered normal or abnormal by Kardia.

The patient overview page also displays blood pressure information if the patient is utilizing certain Omron devices that work with Kardia.

image

The display shows that, after our office visit, he maintained NSR for 3 days (green dots) and then intermittently had ECG recordings classified as Afib (yellow dots) or unclassified (black).

The more he used the device and got feedback on when he was in or out of rhythm, the more he was able to recognize symptoms that were caused by Afib.

I can click on any of the dots and 6-second strips of the full recording are displayed. In the example below, I clicked on 2/27 which has both an unclassified recording (actually atrial flutter) and an Afib recording.

image

Clicking on the ECG strips brings up the full 30-second recording on a page that also allows me to assign my formal interpretation. In the example below, I added atrial flutter as the diagnosis, changing it from Kardia's unclassified. (Kardia's algorithm calls "unclassified" anything it cannot clearly identify as Afib that is over 100 BPM.)

image

The ECG can then be archived or exported for entry into an electronic health record.

The benefits of this patient being connected to me are obvious: We now have an instantaneous patient-controlled method for knowing what his cardiac rhythm is doing and whether he is having symptoms.

This knowledge allows me to make more informed treatment decisions.

The Kardia Pro Dashboard

When I log into Kardia Pro I see this screen.

image

It contains buttons for searching for a specific patient or adding a new patient. Adding new patients is a quick and simple process requiring input of patient demographics, including email and birth date.

From the opening screen, you can click on your triage tab. I have elected to have all non-normal, patient-recorded ECGs go into the triage tab.

Other Examples

Another patient's Kardia Pro page shows that he records an ECG nearly every day, and most of the time Kardia documents NSR in the 60s. Overall, he has made 773 recordings and 677 of them were NSR, 28 unanalyzed (due to brevity) , 13 unclassified and 55 showing AF.

image

Monitoring Rate Control After Cardioversion

Another patient I recently saw for the first time has had long-standing persistent Afib. His previous cardiologist performed an electrical cardioversion a year ago, but the patient reverted back to Afib in 40 hours. Before seeing me, he had purchased a Kardia mobile ECG device and was using it to monitor his heart rate.

After he accepted my email invitation to connect via Kardia Pro, I was able to see his rhythm and rate daily. The Kardia Pro chart below shows his daily heart rate while in atrial fibrillation. We utilized this to guide titration of his rate-controlling medications. Such precise remote monitoring of heart rate in Afib (which is often difficult to accurately assess by standard heart rate devices) obviates the need for office visits for 12-lead ECGs or periodic Holter monitors.

image

I performed a second cardioversion on him after which he made daily recordings documenting maintenance of NSR. With this system, we can determine exactly when Afib returns, information that will be very helpful in determining future treatment options.

A Personal, Intermittent Long-Term Rhythm Monitor

There are many potential applications of the Kardia ECG device beyond Afib monitoring (assessing palpitations, premature ventricular contractions, tachycardia, etc.), but they are all enhanced when the device is combined with a good cardiologist connected to the device by Kardia Pro.

I've gotten spoiled by the information I get from my Afib patients who are on Kardia Pro now. When they call the office with palpitations or a sense of being out of rhythm, I can determine within a minute what their rhythm is wherever I am (excluding tropical beaches and mountain tops) or wherever the patient is (for the most part).

On the other hand, patients who are not on Kardia Pro have to come into the office for 12-lead ECGs. When they call, I feel like my diagnostic tools are limited. Such patients usually end up getting one of the standard Long Term Monitoring Devices. If I am fortunate, after a few days to weeks, the results of the Long Term Monitor will be faxed to my office.

I am optimistic, based on this early experience with Kardia Pro, that ultimately this service in conjunction with the Kardia Mobile ECG device (or similar products) will replace many of the more expensive and inconvenient long-term monitoring devices that cardiologists currently use.

is a private practice noninvasive cardiologist and medical director of echocardiography at St. Luke's Hospital in St. Louis. He blogs on nutrition, cardiac testing, quackery, and other things worthy of skepticism at , where a version of this post first appeared.