Fitness Tracker Applications May Save Lives in the ER

A new case report describes how emergency physicians interrogated smartphone activity tracker data to treat new-onset atrial fibrillation (AF) with electrical cardioversion.

Researchers at Thomas Jefferson University and Our Lady of Lourdes Medical Center reported the case of a 42-year-old male who presented at the emergency room (ER) with newly diagnosed AF of an unknown duration. By interrogating the patient’s wrist-worn Fitbit activity tracker and the smartphone application, they were able to identify onset of arrhythmia within the previous three hours, permitting electro-cardioversion and subsequent discharge.


The treatment of recent onset AF is via electrical cardioversion, if the patient can reliably relate an arrhythmia onset time within the previous 48 hours. But since the patient was asymptomatic during the episode, it was not possible to assign an onset time for his arrhythmia. After it was established via the Fitbit and the sedated patient underwent cardioversion, the smartphone app was interrogated again, accurately recording the change in heart rate as consistent with a rhythm change from AF to normal rhythm. The patient was discharged home with instructions to follow up with outpatient cardiology. The case report was published on April 1, 2016, in Annals of Emergency Medicine.

“Using the patient's activity tracker, in this case, a Fitbit, we were able to pinpoint exactly when the patient's normal heart rate of 70 jumped up to 190,” said corresponding author Alfred Sacchetti, MD, of Our Lady of Lourdes Medical Center. “The device told us that the patient's atrial fibrillation was present for only a few hours. That was well within the 48-hour window needed to consider him for rhythm conversion, so we cardioverted him and sent him home.”

"At present, activity trackers are not considered approved medical devices and use of their information to make medical decisions is at the clinician's own discretion,” concluded Dr. Sacchetti. “However, the increased use of these devices has the potential to provide emergency physicians with objective clinical information prior to the patient's arrival at the emergency department.”

The Fitbit activity wristband offers continuous heart rate monitoring to better estimate daily activity, tracked workouts, monitor resting heart rate, and evaluate sleep quality. Advanced tracking record daily steps and calories by day, and monitor sleep by night, automatically switching between modes based on movement and heart rate data. The device is linked by an app to a smartphone, allowing real time monitoring of daily data.

Related Links:
Thomas Jefferson University
Our Lady of Lourdes Medical Center
Fitbit