The US Food and Drug Administration (FDA) and Conformité Européenne (CE) have both cleared the electrocardiogram (ECG) app on Fitbit's new Sense smartwatch, allowing it to track heart rhythms and detect irregular heartbeats, including signs of atrial fibrillation (AFib), which puts people at risk for stroke and other conditions.

The clearance by both bodies means the ECG app will be available to Fitbit Sense users in the US, UK, Germany, Austria, Luxembourg, the Netherlands, Sweden, Switzerland, Czech Republic, Poland, Belgium, Portugal, Romania, Ireland, Italy, Spain, France, Hong Kong and India.

The Fitbit ECG app, unveiled in Fitbit's recent autumn product launch, is intended to improve heart health, prevent more serious conditions, and potentially save lives. As part of the submission process to the FDA, Fitbit said it conducted a "multi-site clinical trial" across the US, with the goal of studying whether its algorithm can accurately detect AFib from normal sinus rhythm and generate an ECG trace, a recording of a heart's electrical rhythm.

Fitbit said the study showed the algorithm demonstrated the ability to detect 98.7 per cent of AFib cases. However, it was a small study. In May, the company announced it would conduct a larger study to continue testing how well its devices can identify AFib. The study is hoping to enroll hundreds of thousands.

"Helping people understand and manage their heart health has always been a priority for Fitbit and our new ECG app is designed for those users who want to assess themselves in the moment and review the reading later with their doctor," said Eric Friedman, Fitbit co-founder and CTO in a statement. "Early detection of AFib is critical, and I'm incredibly excited that we are making these innovations accessible to people around the world to help them".

Fitbit Sense features an electrodermal activity (EDA) sensor and is Fitbit's first device capable of reading a heart for heart rhythm irregularity AFib. Users simply hold their fingers to the ring on the watch and stay still for 30 seconds to get a reading that can be downloaded and shared with a doctor. 

Fitbit Sense is available now for pre-order on Fitbit.com and online retailers for £300 in carbon/graphite stainless steel and lunar white/soft gold stainless steel.

It is reportedly the third wearable app to get FDA clearance for ECG in the US. Apple Watch did in 2018, and Samsung said it received the designation at an Unpacked event in August.