TSilicon Vallei first offered an ECG service to Apple Vatch Series 4 last year.
However, doctors have previously expressed concern about the accuracy of technology and have called for it to be used together with appropriate consultations.
According to the NHS, atrial fibrillation affects about 1m people in the UK and can affect adults of any age. The researchers concluded that study data can be used as an additional tool for doctors who diagnose patients.
"The doctor can use the information from the study, combines them with their assessment … and then directs clinical decisions on what to do with the warning," said Dr.