Atrial fibrillation is the most common heart rhythm disorder in adults and causes the heart to beat irregularly and too fast. However, the normal heart rhythm can be restored in a healthcare facility with the help of a procedure called cardioversion.
The problem is that the treatment is resource-intensive, while many patients spontaneously regain their normal rhythm before the planned cardioversion - without feeling any difference in symptoms. If this is discovered on the same day, no new patient can be called in.
Reduces late cancellations
Researchers at Danderyd Hospital and the Karolinska Institute studied patients who were to undergo cardioversion between 2022 and 2025. They were asked to record their heart rhythm twice a day using their mobile phones.
When the mobile measurements showed that the heart rhythm had spontaneously returned to normal, it was confirmed using a regular ECG and the cardioversion was canceled in advance.
This significantly reduced the number of late cancellations, according to the researchers.
We have compared it with what is considered today's standard, examining with a regular ECG, and it is, so to speak, just as good, says Johan Engdahl, professor of cardiology at Karolinska Institutet and senior physician at the heart clinic at Danderyd Hospital.
In addition, 99 percent of the more than 200 patients who participated in the study had their own mobile phone, despite an average age of 70 years - which means that the method has general potential to increase accessibility to heart rhythm assessment, according to Engdahl.
Reading via mobile camera
He says that all that is needed is an app developed within the study. The technology is based on photoplethysmography, PPG, where the mobile phone's camera reads pulse signals from the finger.
The app is still approved for research purposes only.
These are simple things, technology that is already available and that everyone has in their pocket and that can be used in a good and smart way. We hope we can move forward with this, says Engdahl.
The study has been published in the scientific journal JAMA Cardiology.
