TUESDAY, June 16, 2026 (HealthDay News) -- Daily heart rhythm monitoring at home using a smartphone significantly reduces the number of same-day cancellations among patients scheduled for electrical cardioversion for atrial fibrillation, according to a study published online June 3 in JAMA Cardiology.Jonatan Fernstad, M.D., Ph.D., from the Karolinska Institutet in Stockholm, and colleagues compared the efficacy and feasibility of precardioversion rhythm monitoring using smartphone photoplethysmography compared to standard of care in scheduled cardioversion of atrial fibrillation. The analysis included 203 adult patients with persistent atrial fibrillation or flutter scheduled for cardioversion who were randomly assigned to ambulatory heart rhythm monitoring using smartphone photoplethysmography and reminders to support adherence to anticoagulation, or to standard of care.The researchers found that participants performed 5,226 heart rhythm recordings precardioversion, with a median number of daily recordings per participant of 2.1. The number of same-day cancellations of scheduled cardioversions was significantly lower in the intervention group compared with the control group (4.8 versus 23.3 percent). For same-day cancellations due to spontaneous sinus rhythm conversion, the frequency was 1.0 percent in the intervention group versus 18.2 percent in the control group."We are pleased to see that the method could help avoid unnecessary health care visits, and that so many patients were able to record their heart rhythm independently from home using a smartphone," Fernstad said in a statement.Several authors disclosed ties to the pharmaceutical industry.Abstract/Full Text (subscription or payment may be required).Sign up for our weekly HealthDay newsletter