Ambulatory ECG monitoring in the age of smartphones

Cleveland Clinic Journal of Medicine. 2019 July;86(7):483-493 | 10.3949/ccjm.86a.18123
July 1, 2019|Cleveland Clinic Journal of Medicine
David Sanders, MD;Leo Ungar, MD;Michael A. Eskander, MD;Arnold H. Seto, MD, MPA
Author and Disclosure Information

David Sanders, MD
Cardiology Fellow, Rush University Medical Center, Chicago, IL

Leo Ungar, MD
Cardiology Fellow, University of California, Irvine, CA

Michael A. Eskander, MD
Cardiac Electrophysiology Fellow, University of California, San Diego, CA

Arnold H. Seto, MD, MPA
Chief of Cardiology, Long Beach Veterans Affairs Medical Center, Long Beach, CA

Address: David Sanders, MD, Rush University Medical Center, 1725 West Harrison Street, Professional Building, Suite 1159, Chicago, IL 60612; djsanders13@gmail.com

Release date: July 1, 2019
Expiration date: June 30, 2020
Estimated time of completion: 1 hour

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ABSTRACT

Ambulatory electrocardiography (ECG) allows for extended monitoring of arrhythmias in a real-world setting. This article reviews the currently available ambulatory ECG devices and their differences in design, function, indications, efficacy, cost, and optimal use in clinical practice.

KEY POINTS

  • Ambulatory ECG monitoring is commonly used to correlate symptoms with arrhythmia, confirm occult atrial fibrillation, and assess the efficacy of antiarrhythmic therapy.
  • Devices have features such as access to the full monitoring time (“full disclosure”), extended monitoring, and telemetry, each with advantages and limitations.
  • Consumer-oriented wearable devices are aimed at arrhythmia monitoring, which could lead to increased arrhythmia detection, but at the risk of more false-positive results and excessive use of healthcare resources.

DISRUPTIVE TECHNOLOGY AND DIRECT-TO-CONSUMER MARKETING

The development of smartphone and watch ECG technology has led to a rise in direct-to-consumer healthcare delivery. By devising technology that is appealing, useful, and affordable, companies can bypass the insurer and practitioner by targeting increasingly health-literate consumers. For many companies, there is great motivation to enter this healthcare space. Wearable devices are immensely popular and, as a result, generate substantial revenue. One analysis estimates that 1 in 10 Americans (nearly 30 million) owns a wearable, smart-technology device.37

This direct-to-consumer approach has specific implications for cardiology and, more broadly, for healthcare overall. By directly selling to consumers, companies have an opportunity to reach many more people. The Apple Watch Series 4 has taken this a step further: by including this technology in the watch, consumers not necessarily seeking an ambulatory cardiac monitor will have one with a watch purchase. This could lead to increases in monitoring and could alert people to previously undiagnosed disorders.

For consumers, this technology can empower them to choose how and when to be monitored. Further, it gives them personal control of their healthcare data, and helps move the point of care out of hospitals and clinics and into the home.

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But wearable medical technology and direct-to-consumer healthcare have risks. First, in the absence of appropriate regulation, patients have to distinguish between products that are well validated and those that are unproven. Consumers also may inappropriately use devices for indications or in scenarios for which the value is uncertain.

Also, there is potential for confusion and misunderstanding of results, including false-positive readings, which could lead to excessive and costly use of unnecessary diagnostic workups. Instead of providing peace of mind, these devices could cause greater worry. This may be especially true with the newest Apple watch, as this product will introduce ambulatory ECG to a younger and healthier segment of the population who are less likely to have true disease.

Further, these devices have algorithms that detect atrial fibrillation, but is it the same as that detected by traditional methods? Sometimes termed “subclinical” atrial fibrillation, it poses uncertainties: ie, Do patients need anticoagulation, pharmacologic therapy, and ablation? The optimal management of subclinical atrial fibrillation, as well as its similarities to and differences from atrial fibrillation diagnosed by traditional methods, are topics that need further study.

Wearable technology is still developing and will continue to do so. Medical practice will have to adapt to it.

FUTURE DIRECTIONS

Changes in technology have led to remarkable advances in the convenience and accuracy of ambulatory ECG monitoring. Ongoing research is expected to lead to even more improvements. Devices will become more ergonomic and technically capable, and they may expand monitoring to include other biologic parameters beyond ECG.

Comfort is important to ensure patient adherence. Newer, flexible electronics embedded in ultrathin materials can potentially improve the wearability of devices that require gel electrodes or adhesive patches.38 Wireless technology may obviate the need for on-skin attachments. Future recording systems may be embedded into clothing or incorporated into wearable vests capable of wirelessly transmitting ECG signals to separate recording stations.39

In addition to becoming smaller and more comfortable, future devices will be more technically capable, leading to a merging of technologies that will further blur the distinctions among devices. Eventually, the features of full disclosure, extended monitoring duration, and telemetric communication will all be present together. Perhaps more important is that ambulatory ECG devices may become fully capable biosensor monitors. These devices would have the potential to monitor respiratory frequency, peripheral oxygen saturation, potassium levels, and arterial pulse pressure.39,40