“Consumer wearable devices like smartwatches are now being used by the general population to track vital signs and exercise output as well as advanced health metrics that can be valuable in the detection and management of A-fib,” said Dr. Brett Faulknier, cardiac electrophysiologist at Cleveland Clinic Indian River Hospital.
Atrial fibrillation (A-fib) is a common cardiac arrhythmia characterized by irregular and often rapid heartbeats. Effective management of A-fib requires continuous monitoring of heart rhythm to detect episodes and assess treatment efficacy. Wearable heart monitors like smartwatches and fitness trackers have emerged as promising tools for monitoring A-fib outside clinical settings.
“One of the primary benefits of consumer wearable devices (CWDs) is their ability to provide continuous, real-time monitoring of heart rhythm which facilitates early intervention and timely adjustments to treatment plans,” Dr. Brett Faulknier said. “But with this massive expansion of data collected at the individual patient level, careful interpretation is imperative.”
The validity of CWDs in detecting A-fib episodes has been a subject of scrutiny. Studies have demonstrated varying levels of accuracy among different devices. Some wearables exhibit high sensitivity and specificity in detecting A-fib while others may produce false positives or negatives. Factors such as sensor technology, signal processing algorithms and device placement influence the reliability of heart rhythm detection.
Some of the challenges and pitfalls of interpreting data collected by CWDs were explored in a 2023 article published by the American College of Cardiology Foundation. The article asserts that CWDs measure heart rate using either PPG or ECG.
PPG is used in most wrist- and finger-worn CWDs. PPG relies on the use of light-emitting diodes, which emit light at specific wavelengths toward the skin. The intensity and pulsatility of light reflected from blood vessels is then measured by a photodector and converted into estimates of blood flow and heart rate. Commercial chest straps use electrode-based ECG methods to measure heart rate which is consistently more accurate in heart rate measurement.
A primary determinant of PPG accuracy is the anatomic location of measurement. PPG-based biosensors worn on the wrists have the largest median error rate. Wrist motion may shift the CWD position relative to the skin surface, thereby distancing sensors from their intended measurement location. Improper CWD fit is another source of error. Wrist-worn CWDs that are too loose may not accurately detect PPG signals, and those too tight may result in impaired blood flow, resulting in inaccurate PPG measurement.
“In one review assessing the accuracy of wrist worn CWD heart rate data collected by nine different manufactures, the PPG-based heart rate measurement demonstrated plus or minus 3 percent measurement error in controlled settings compared to reference standard devices,” Dr. Faulknier explained. “So, while the wrist devices are good, the gold standard technique to assess heart rate remains the use of conventional clinically electro-based chest straps.” Additionally, the studies show sensitivity of A-fib detection ranged between 69 percent and 79 percent.
Even with the margin of error, CWDs are valuable tools in the treatment and management of A-Fib in many ways. Wearables enable early detection of A-fib episodes, in many cases, allowing healthcare providers to intervene promptly and prevent complications such as stroke or heart failure.
By tracking heart rhythms over time, wearables can identify triggers and risk factors specific to each patient that can be used to formulate personalized treatment strategies.
CWDs’ remote monitoring capabilities allow healthcare providers to access and review the patient’s heart rhythms and adjust treatment plans without the need for an office visit.
“I encourage my patients to use a consumer wearable device to just try to give some indication if they are potentially going in or out of rhythm,” Dr. Faulknier explained.
“Getting data from a wearable will not lead us into making clinical decisions, but it can assist us in managing these patients on a day-to-day basis.
“If the patient gets to know his regular heart rate and sees something they are not comfortable with in the data, they can ask us about it. Everyone can benefit from looking at a CWD for standard things like the time they exercise, the number of steps they take and their heart rate range. If they want to dive deeper, they can learn how to read extra cardiac health metrics.
“The exercise function of time and step count is probably the most important feature on a wearable for the average person,” Dr. Faulknier continued. “The number of steps that you take in a day and the intensity is important to your health.
“If you do moderate intensity, it’s recommended 150 to 300 minutes per week. More vigorous intensity should be done 75 to 150 minutes per week for health and longevity.
There is a lower mortality risk among adults older than 60 who achieve up to 6,000 to 8,000 steps per day and among those adults less than 60 who achieve up to 8,000 to 10,000 steps a day.”
Despite challenges related to the accuracy and reliability of some devices, advancements in wearable device technology have made them more useful in detecting and managing A-fib episodes and also inspired millions of people to track their own health and fitness on a daily basis – which turns out to be a very good thing.
In fact, a national Cleveland Clinic survey showed that 4 out of 5 Americans using health monitoring technologies noticed positive changes to their physical and mental health; 60 percent track their daily step count with 50 percent saying they are getting in more steps per day then they did before using the wearable device. More than 50 percent monitor their heart rate/pulse, 40 percent track their burned calories and 32 percent track their blood pressure. Some 53 percent say they exercise more regularly since wearing a CWD, and 34 percent are improving their eating habits.
Dr. Brett Faulknier is board-certified in adult cardiovascular disease and cardiac electrophysiology. Prior to joining Cleveland Clinic Indian River Hospital, he served seven years as section director of electrophysiology and associate professor of medicine at West Virginia University Charleston. Faulknier received his Doctor of Osteopathic Medicine degree from West Virginia School of Osteopathic Medicine and completed fellowships in adult cardiovascular disease and cardiovascular electrophysiology. Dr. Faulknier’s office is located at the Health and Wellness Center at Cleveland Clinic. For more information or to schedule an appointment, call 772-226-4830.
