Can Fitbit detect AFib?

Researchers track whether wearable fitness devices such as Fitbit can detect atrial fibrillation (AFib).

As of 2019, there were 28 million active users of the physical activity tracker, Fitbit,1 and at least 19% of Americans owned a wearable activity tracker.2 Fitbit devices are popular fitness trackers, and the market for activity tracking devices is only expected to grow. The forecast for wearables activity tracker shipments worldwide is expected to reach 631.7 million shipments by 2024.3

Usually, activity trackers such as Fitbit are worn on the wrist like a watch. There are many different models of Fitbit devices. Depending on the type, the wearables can track a variety of physical data, such as exercise, intensity, inactivity, steps taken, heart rate, blood pressure, and even amount and quality of sleep.

Fitbits use different tracking sensors to measure physical data. Most wearables use accelerometers or gyroscopes to measure activity levels. Global positioning systems (GPS) and barometers are also used to accurately measure activity and movement. The different sensors all have differing levels of accuracy, but do not use as much battery life.4

Activity trackers can also be used to measure blood pressure, fluid electrolytes, and cardiac output, but are not commonly available in wristband form.

Healthcare practitioners quickly realized the potential value of fitness trackers as a means to monitor health conditions. Because they provide a more accurate assessment of a person’s activity levels, healthcare practitioners could rely on data from the health trackers instead of foggy memories. Data on exercise intensity would no longer be subjective but could be quantified for real time assessment. Fitness trackers also have value as motivators of healthy behaviors and can help wearers set and reach their fitness goals.

One such common, but difficult to detect condition is atrial fibrillation (AFib). Atrial fibrillation is an abnormal heartbeat. It occurs when the upper chambers of the heartbeat irregularly, out of sync with the lower chambers5  AFib can lead to stroke or heart failure ( AFib affects up to 34 million people worldwide but is difficult to detect.6 Often people experiencing AFib do not show any outward symptoms.

Because of the prevalence and the popularity of activity trackers, healthcare practitioners wondered can Fitbit detect AFib? To determine can Fitbit detect AFib, healthcare practitioners at Fitbit conducted a large-scale clinical trial in 2020 called the Fitbit Heart Study.7

Participants in the Fitbit Heart Study wore Fitbit activity trackers and reported heart data. Any participant that showed signs of AFib was alerted and connected with a healthcare practitioner for a virtual appointment. Fitbits’ sensors use photoplethysmography (PPG) technology to measure blood flow and heart rates.  From this, the Fitbit algorithm calculated heart rhythm, which allowed it to detect atrial fibrillation if it occurred.7

The Fitbit Heart Study showed that Fitbit’s algorithm was 98.8% successful in AFib detection, and 100% accurate in identifying normal heart rhythms. The FDA granted 510(k) clearance for the device.8

The AFib algorithm is available to users of the Fitbit Sense, the company’s first wearable with an ECG app. The device contains an electrodermal activity sensor for stress management, and up to six hours of battery life.

While an activity tracker is not a substitute for regular check-ups with your healthcare practitioner, it did answer the question, ‘Can Fitbit detect AFib?’ with a resounding yes. It is important to remember that activity trackers can be part of a holistic personal health program. The data they provide helps users get up and leave the sedentary lifestyle behind them.

One should always consult their healthcare practitioner before beginning any new diet or exercise plan.


Image by Daniel Reche from Pixabay

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