Smartphone Heart Monitoring Tied to Lower Cancellation – EMJ

SMARTPHONE MONITORING initiated in the weeks leading up to scheduled cardioversion treatments led to a significant decrease in the number of same-day cancellations, according to a new study from Sweden.¹

Cardioversion is a commonly scheduled procedure for the treatment of arrythmias, namely atrial fibrillation and atrial flutter. While the procedure requires significant resource investment from healthcare systems, same-day cancellations are common due to spontaneous conversion from atrial fibrillation to sinus rhythm. This can result in unnecessary hospital visits for patients and wasted healthcare resources.

The SMARTBEATS Randomized Clinical Trial

The study followed 206 patients aged at least 18 years, with persistent atrial fibrillation or flutter, who were scheduled for cardioversion. The randomised clinical trial took place between 2022 and 2025, with the participants split into intervention and standard-of-care (control) groups.

In the intervention group, participants’ heart rhythms were monitored daily one to two weeks ahead of their scheduled cardioversion, using smartphone-based photoplethysmography (PPG): an optical technique used to measure blood oxygen saturation and volume in pulse oximetry.² Participants were also prompted with daily reminders to support their adherence to anticoagulation treatments.¹

Fewer Same-Day Cancellations

Following the exclusion of participants with cardiac implantable electronic devices, 104 intervention and 99 control participants were included in the final analysis. When spontaneous conversion to sinus rhythm was observed in the intervention group, that participant’s cardioversion was cancelled.

Researchers found that there were 4.8% (5/104) same-day cancellations of participants in the intervention group, in comparison to 23.2% (23/99) in the control group. For same-day cancellations due to spontaneous conversion to sinus rhythm, the researchers found that they account for 1.0% (1/104) of the intervention group and 18.2% (18/99) of the control group (p=<0.001).

Improving Healthcare Efficiency and Access

“Among the patients who participated in the study, 99 percent owned a smartphone even though the median age was 70 years. This means that smartphone-based heart rhythm diagnostics has the potential to improve access to heart rhythm assessment more generally,” said Johan Engdahl, professor of cardiology at Karolinska Institutet and senior consultant at the Department of Cardiology, Danderyd Hospital, Stockholm, Sweden.

“This is important because untreated atrial fibrillation increases the risk of stroke and heart failure. In upcoming research projects, we will study how effective the method is at detecting previously unknown atrial fibrillation compared with current methods used in healthcare.”

These findings highlight the potential for smartphone-based PPG, as a highly scalable digital intervention which could result in fewer same-day cancellations, and ultimately reduce unnecessary healthcare visits for patients and optimise healthcare resources. Additional research is needed to understand smartphone-based heart rhythm diagnostics’ capability beyond supporting pre-cardioversion monitoring.

References

¹Fernstad Jet al. Precardioversion heart rhythm monitoring using smartphone photoplethysmography: the SMARTBEATS randomized clinical trial. JAMA Cardiol. 2026; DOI:10.1001/jamacardio.2026.1269.

²Elgendi, M et al. The use of photoplethysmography for assessing hypertension. npj Digit. Med. 2019;DOI:10.1038/s41746-019-0136-7.

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